79bd9814e5
cgroup_event is way over-designed and tries to build a generic flexible event mechanism into cgroup - fully customizable event specification for each user of the interface. This is utterly unnecessary and overboard especially in the light of the planned unified hierarchy as there's gonna be single agent. Simply generating events at fixed points, or if that's too restrictive, configureable cadence or single set of configureable points should be enough. Thankfully, memcg is the only user and gets to keep it. Replacing it with something simpler on sane_behavior is strongly recommended. This patch moves cgroup_event and "cgroup.event_control" implementation to mm/memcontrol.c. Clearing of events on cgroup destruction is moved from cgroup_destroy_locked() to mem_cgroup_css_offline(), which shouldn't make any noticeable difference. cgroup_css() and __file_cft() are exported to enable the move; however, this will soon be reverted once the event code is updated to be memcg specific. Note that "cgroup.event_control" will now exist only on the hierarchy with memcg attached to it. While this change is visible to userland, it is unlikely to be noticeable as the file has never been meaningful outside memcg. Aside from the above change, this is pure code relocation. v2: Per Li Zefan's comments, init/Kconfig updated accordingly and poll.h inclusion moved from cgroup.c to memcontrol.c. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Balbir Singh <bsingharora@gmail.com>
7260 lines
192 KiB
C
7260 lines
192 KiB
C
/* memcontrol.c - Memory Controller
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*
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* Copyright IBM Corporation, 2007
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* Author Balbir Singh <balbir@linux.vnet.ibm.com>
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*
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* Copyright 2007 OpenVZ SWsoft Inc
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* Author: Pavel Emelianov <xemul@openvz.org>
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*
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* Memory thresholds
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* Copyright (C) 2009 Nokia Corporation
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* Author: Kirill A. Shutemov
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*
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* Kernel Memory Controller
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* Copyright (C) 2012 Parallels Inc. and Google Inc.
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* Authors: Glauber Costa and Suleiman Souhlal
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#include <linux/res_counter.h>
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#include <linux/memcontrol.h>
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#include <linux/cgroup.h>
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#include <linux/mm.h>
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#include <linux/hugetlb.h>
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#include <linux/pagemap.h>
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#include <linux/smp.h>
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#include <linux/page-flags.h>
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#include <linux/backing-dev.h>
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#include <linux/bit_spinlock.h>
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#include <linux/rcupdate.h>
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#include <linux/limits.h>
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#include <linux/export.h>
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#include <linux/mutex.h>
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#include <linux/rbtree.h>
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#include <linux/slab.h>
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#include <linux/swap.h>
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#include <linux/swapops.h>
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#include <linux/spinlock.h>
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#include <linux/eventfd.h>
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#include <linux/poll.h>
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#include <linux/sort.h>
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#include <linux/fs.h>
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#include <linux/seq_file.h>
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#include <linux/vmalloc.h>
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#include <linux/vmpressure.h>
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#include <linux/mm_inline.h>
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#include <linux/page_cgroup.h>
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#include <linux/cpu.h>
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#include <linux/oom.h>
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#include <linux/lockdep.h>
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#include <linux/file.h>
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#include "internal.h"
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#include <net/sock.h>
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#include <net/ip.h>
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#include <net/tcp_memcontrol.h>
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#include <asm/uaccess.h>
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#include <trace/events/vmscan.h>
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struct cgroup_subsys mem_cgroup_subsys __read_mostly;
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EXPORT_SYMBOL(mem_cgroup_subsys);
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#define MEM_CGROUP_RECLAIM_RETRIES 5
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static struct mem_cgroup *root_mem_cgroup __read_mostly;
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#ifdef CONFIG_MEMCG_SWAP
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/* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */
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int do_swap_account __read_mostly;
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/* for remember boot option*/
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#ifdef CONFIG_MEMCG_SWAP_ENABLED
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static int really_do_swap_account __initdata = 1;
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#else
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static int really_do_swap_account __initdata = 0;
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#endif
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#else
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#define do_swap_account 0
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#endif
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static const char * const mem_cgroup_stat_names[] = {
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"cache",
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"rss",
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"rss_huge",
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"mapped_file",
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"writeback",
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"swap",
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};
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enum mem_cgroup_events_index {
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MEM_CGROUP_EVENTS_PGPGIN, /* # of pages paged in */
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MEM_CGROUP_EVENTS_PGPGOUT, /* # of pages paged out */
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MEM_CGROUP_EVENTS_PGFAULT, /* # of page-faults */
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MEM_CGROUP_EVENTS_PGMAJFAULT, /* # of major page-faults */
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MEM_CGROUP_EVENTS_NSTATS,
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};
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static const char * const mem_cgroup_events_names[] = {
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"pgpgin",
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"pgpgout",
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"pgfault",
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"pgmajfault",
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};
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static const char * const mem_cgroup_lru_names[] = {
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"inactive_anon",
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"active_anon",
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"inactive_file",
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"active_file",
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"unevictable",
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};
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/*
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* Per memcg event counter is incremented at every pagein/pageout. With THP,
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* it will be incremated by the number of pages. This counter is used for
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* for trigger some periodic events. This is straightforward and better
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* than using jiffies etc. to handle periodic memcg event.
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*/
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enum mem_cgroup_events_target {
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MEM_CGROUP_TARGET_THRESH,
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MEM_CGROUP_TARGET_SOFTLIMIT,
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MEM_CGROUP_TARGET_NUMAINFO,
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MEM_CGROUP_NTARGETS,
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};
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#define THRESHOLDS_EVENTS_TARGET 128
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#define SOFTLIMIT_EVENTS_TARGET 1024
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#define NUMAINFO_EVENTS_TARGET 1024
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struct mem_cgroup_stat_cpu {
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long count[MEM_CGROUP_STAT_NSTATS];
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unsigned long events[MEM_CGROUP_EVENTS_NSTATS];
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unsigned long nr_page_events;
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unsigned long targets[MEM_CGROUP_NTARGETS];
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};
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struct mem_cgroup_reclaim_iter {
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/*
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* last scanned hierarchy member. Valid only if last_dead_count
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* matches memcg->dead_count of the hierarchy root group.
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*/
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struct mem_cgroup *last_visited;
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unsigned long last_dead_count;
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/* scan generation, increased every round-trip */
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unsigned int generation;
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};
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/*
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* per-zone information in memory controller.
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*/
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struct mem_cgroup_per_zone {
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struct lruvec lruvec;
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unsigned long lru_size[NR_LRU_LISTS];
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struct mem_cgroup_reclaim_iter reclaim_iter[DEF_PRIORITY + 1];
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struct rb_node tree_node; /* RB tree node */
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unsigned long long usage_in_excess;/* Set to the value by which */
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/* the soft limit is exceeded*/
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bool on_tree;
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struct mem_cgroup *memcg; /* Back pointer, we cannot */
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/* use container_of */
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};
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struct mem_cgroup_per_node {
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struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES];
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};
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/*
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* Cgroups above their limits are maintained in a RB-Tree, independent of
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* their hierarchy representation
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*/
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struct mem_cgroup_tree_per_zone {
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struct rb_root rb_root;
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spinlock_t lock;
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};
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struct mem_cgroup_tree_per_node {
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struct mem_cgroup_tree_per_zone rb_tree_per_zone[MAX_NR_ZONES];
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};
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struct mem_cgroup_tree {
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struct mem_cgroup_tree_per_node *rb_tree_per_node[MAX_NUMNODES];
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};
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static struct mem_cgroup_tree soft_limit_tree __read_mostly;
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struct mem_cgroup_threshold {
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struct eventfd_ctx *eventfd;
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u64 threshold;
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};
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/* For threshold */
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struct mem_cgroup_threshold_ary {
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/* An array index points to threshold just below or equal to usage. */
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int current_threshold;
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/* Size of entries[] */
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unsigned int size;
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/* Array of thresholds */
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struct mem_cgroup_threshold entries[0];
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};
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struct mem_cgroup_thresholds {
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/* Primary thresholds array */
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struct mem_cgroup_threshold_ary *primary;
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/*
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* Spare threshold array.
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* This is needed to make mem_cgroup_unregister_event() "never fail".
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* It must be able to store at least primary->size - 1 entries.
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*/
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struct mem_cgroup_threshold_ary *spare;
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};
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/* for OOM */
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struct mem_cgroup_eventfd_list {
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struct list_head list;
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struct eventfd_ctx *eventfd;
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};
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/*
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* cgroup_event represents events which userspace want to receive.
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*/
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struct cgroup_event {
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/*
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* css which the event belongs to.
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*/
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struct cgroup_subsys_state *css;
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/*
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* Control file which the event associated.
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*/
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struct cftype *cft;
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/*
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* eventfd to signal userspace about the event.
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*/
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struct eventfd_ctx *eventfd;
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/*
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* Each of these stored in a list by the cgroup.
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*/
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struct list_head list;
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/*
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* All fields below needed to unregister event when
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* userspace closes eventfd.
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*/
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poll_table pt;
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wait_queue_head_t *wqh;
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wait_queue_t wait;
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struct work_struct remove;
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};
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static void mem_cgroup_threshold(struct mem_cgroup *memcg);
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static void mem_cgroup_oom_notify(struct mem_cgroup *memcg);
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/*
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* The memory controller data structure. The memory controller controls both
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* page cache and RSS per cgroup. We would eventually like to provide
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* statistics based on the statistics developed by Rik Van Riel for clock-pro,
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* to help the administrator determine what knobs to tune.
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*
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* TODO: Add a water mark for the memory controller. Reclaim will begin when
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* we hit the water mark. May be even add a low water mark, such that
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* no reclaim occurs from a cgroup at it's low water mark, this is
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* a feature that will be implemented much later in the future.
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*/
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struct mem_cgroup {
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struct cgroup_subsys_state css;
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/*
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* the counter to account for memory usage
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*/
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struct res_counter res;
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/* vmpressure notifications */
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struct vmpressure vmpressure;
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/*
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* the counter to account for mem+swap usage.
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*/
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struct res_counter memsw;
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/*
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* the counter to account for kernel memory usage.
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*/
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struct res_counter kmem;
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/*
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* Should the accounting and control be hierarchical, per subtree?
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*/
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bool use_hierarchy;
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unsigned long kmem_account_flags; /* See KMEM_ACCOUNTED_*, below */
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bool oom_lock;
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atomic_t under_oom;
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atomic_t oom_wakeups;
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int swappiness;
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/* OOM-Killer disable */
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int oom_kill_disable;
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/* set when res.limit == memsw.limit */
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bool memsw_is_minimum;
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/* protect arrays of thresholds */
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struct mutex thresholds_lock;
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/* thresholds for memory usage. RCU-protected */
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struct mem_cgroup_thresholds thresholds;
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/* thresholds for mem+swap usage. RCU-protected */
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struct mem_cgroup_thresholds memsw_thresholds;
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/* For oom notifier event fd */
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struct list_head oom_notify;
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/*
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* Should we move charges of a task when a task is moved into this
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* mem_cgroup ? And what type of charges should we move ?
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*/
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unsigned long move_charge_at_immigrate;
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/*
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* set > 0 if pages under this cgroup are moving to other cgroup.
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*/
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atomic_t moving_account;
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/* taken only while moving_account > 0 */
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spinlock_t move_lock;
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/*
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* percpu counter.
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*/
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struct mem_cgroup_stat_cpu __percpu *stat;
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/*
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* used when a cpu is offlined or other synchronizations
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* See mem_cgroup_read_stat().
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*/
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struct mem_cgroup_stat_cpu nocpu_base;
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spinlock_t pcp_counter_lock;
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atomic_t dead_count;
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#if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_INET)
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struct tcp_memcontrol tcp_mem;
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#endif
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#if defined(CONFIG_MEMCG_KMEM)
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/* analogous to slab_common's slab_caches list. per-memcg */
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struct list_head memcg_slab_caches;
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/* Not a spinlock, we can take a lot of time walking the list */
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struct mutex slab_caches_mutex;
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/* Index in the kmem_cache->memcg_params->memcg_caches array */
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int kmemcg_id;
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#endif
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int last_scanned_node;
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#if MAX_NUMNODES > 1
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nodemask_t scan_nodes;
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atomic_t numainfo_events;
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atomic_t numainfo_updating;
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#endif
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struct mem_cgroup_per_node *nodeinfo[0];
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/* WARNING: nodeinfo must be the last member here */
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};
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static size_t memcg_size(void)
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{
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return sizeof(struct mem_cgroup) +
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nr_node_ids * sizeof(struct mem_cgroup_per_node);
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}
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/* internal only representation about the status of kmem accounting. */
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enum {
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KMEM_ACCOUNTED_ACTIVE = 0, /* accounted by this cgroup itself */
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KMEM_ACCOUNTED_ACTIVATED, /* static key enabled. */
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KMEM_ACCOUNTED_DEAD, /* dead memcg with pending kmem charges */
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};
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/* We account when limit is on, but only after call sites are patched */
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#define KMEM_ACCOUNTED_MASK \
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((1 << KMEM_ACCOUNTED_ACTIVE) | (1 << KMEM_ACCOUNTED_ACTIVATED))
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#ifdef CONFIG_MEMCG_KMEM
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static inline void memcg_kmem_set_active(struct mem_cgroup *memcg)
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{
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set_bit(KMEM_ACCOUNTED_ACTIVE, &memcg->kmem_account_flags);
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}
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static bool memcg_kmem_is_active(struct mem_cgroup *memcg)
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{
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return test_bit(KMEM_ACCOUNTED_ACTIVE, &memcg->kmem_account_flags);
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}
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static void memcg_kmem_set_activated(struct mem_cgroup *memcg)
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{
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set_bit(KMEM_ACCOUNTED_ACTIVATED, &memcg->kmem_account_flags);
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}
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static void memcg_kmem_clear_activated(struct mem_cgroup *memcg)
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{
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clear_bit(KMEM_ACCOUNTED_ACTIVATED, &memcg->kmem_account_flags);
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}
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static void memcg_kmem_mark_dead(struct mem_cgroup *memcg)
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{
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/*
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* Our caller must use css_get() first, because memcg_uncharge_kmem()
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* will call css_put() if it sees the memcg is dead.
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*/
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smp_wmb();
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if (test_bit(KMEM_ACCOUNTED_ACTIVE, &memcg->kmem_account_flags))
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set_bit(KMEM_ACCOUNTED_DEAD, &memcg->kmem_account_flags);
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}
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static bool memcg_kmem_test_and_clear_dead(struct mem_cgroup *memcg)
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{
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return test_and_clear_bit(KMEM_ACCOUNTED_DEAD,
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&memcg->kmem_account_flags);
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}
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#endif
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/* Stuffs for move charges at task migration. */
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/*
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* Types of charges to be moved. "move_charge_at_immitgrate" and
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* "immigrate_flags" are treated as a left-shifted bitmap of these types.
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*/
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enum move_type {
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MOVE_CHARGE_TYPE_ANON, /* private anonymous page and swap of it */
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MOVE_CHARGE_TYPE_FILE, /* file page(including tmpfs) and swap of it */
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NR_MOVE_TYPE,
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};
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/* "mc" and its members are protected by cgroup_mutex */
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static struct move_charge_struct {
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spinlock_t lock; /* for from, to */
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struct mem_cgroup *from;
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struct mem_cgroup *to;
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unsigned long immigrate_flags;
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unsigned long precharge;
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unsigned long moved_charge;
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unsigned long moved_swap;
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struct task_struct *moving_task; /* a task moving charges */
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wait_queue_head_t waitq; /* a waitq for other context */
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} mc = {
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.lock = __SPIN_LOCK_UNLOCKED(mc.lock),
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.waitq = __WAIT_QUEUE_HEAD_INITIALIZER(mc.waitq),
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};
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static bool move_anon(void)
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{
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return test_bit(MOVE_CHARGE_TYPE_ANON, &mc.immigrate_flags);
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}
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static bool move_file(void)
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{
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return test_bit(MOVE_CHARGE_TYPE_FILE, &mc.immigrate_flags);
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}
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/*
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* Maximum loops in mem_cgroup_hierarchical_reclaim(), used for soft
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* limit reclaim to prevent infinite loops, if they ever occur.
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*/
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#define MEM_CGROUP_MAX_RECLAIM_LOOPS 100
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#define MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS 2
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enum charge_type {
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MEM_CGROUP_CHARGE_TYPE_CACHE = 0,
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MEM_CGROUP_CHARGE_TYPE_ANON,
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MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */
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MEM_CGROUP_CHARGE_TYPE_DROP, /* a page was unused swap cache */
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NR_CHARGE_TYPE,
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};
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/* for encoding cft->private value on file */
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enum res_type {
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_MEM,
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_MEMSWAP,
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_OOM_TYPE,
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_KMEM,
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};
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#define MEMFILE_PRIVATE(x, val) ((x) << 16 | (val))
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#define MEMFILE_TYPE(val) ((val) >> 16 & 0xffff)
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#define MEMFILE_ATTR(val) ((val) & 0xffff)
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/* Used for OOM nofiier */
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#define OOM_CONTROL (0)
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|
|
/*
|
|
* Reclaim flags for mem_cgroup_hierarchical_reclaim
|
|
*/
|
|
#define MEM_CGROUP_RECLAIM_NOSWAP_BIT 0x0
|
|
#define MEM_CGROUP_RECLAIM_NOSWAP (1 << MEM_CGROUP_RECLAIM_NOSWAP_BIT)
|
|
#define MEM_CGROUP_RECLAIM_SHRINK_BIT 0x1
|
|
#define MEM_CGROUP_RECLAIM_SHRINK (1 << MEM_CGROUP_RECLAIM_SHRINK_BIT)
|
|
|
|
/*
|
|
* The memcg_create_mutex will be held whenever a new cgroup is created.
|
|
* As a consequence, any change that needs to protect against new child cgroups
|
|
* appearing has to hold it as well.
|
|
*/
|
|
static DEFINE_MUTEX(memcg_create_mutex);
|
|
|
|
struct mem_cgroup *mem_cgroup_from_css(struct cgroup_subsys_state *s)
|
|
{
|
|
return s ? container_of(s, struct mem_cgroup, css) : NULL;
|
|
}
|
|
|
|
/* Some nice accessors for the vmpressure. */
|
|
struct vmpressure *memcg_to_vmpressure(struct mem_cgroup *memcg)
|
|
{
|
|
if (!memcg)
|
|
memcg = root_mem_cgroup;
|
|
return &memcg->vmpressure;
|
|
}
|
|
|
|
struct cgroup_subsys_state *vmpressure_to_css(struct vmpressure *vmpr)
|
|
{
|
|
return &container_of(vmpr, struct mem_cgroup, vmpressure)->css;
|
|
}
|
|
|
|
struct vmpressure *css_to_vmpressure(struct cgroup_subsys_state *css)
|
|
{
|
|
return &mem_cgroup_from_css(css)->vmpressure;
|
|
}
|
|
|
|
static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg)
|
|
{
|
|
return (memcg == root_mem_cgroup);
|
|
}
|
|
|
|
/* Writing them here to avoid exposing memcg's inner layout */
|
|
#if defined(CONFIG_INET) && defined(CONFIG_MEMCG_KMEM)
|
|
|
|
void sock_update_memcg(struct sock *sk)
|
|
{
|
|
if (mem_cgroup_sockets_enabled) {
|
|
struct mem_cgroup *memcg;
|
|
struct cg_proto *cg_proto;
|
|
|
|
BUG_ON(!sk->sk_prot->proto_cgroup);
|
|
|
|
/* Socket cloning can throw us here with sk_cgrp already
|
|
* filled. It won't however, necessarily happen from
|
|
* process context. So the test for root memcg given
|
|
* the current task's memcg won't help us in this case.
|
|
*
|
|
* Respecting the original socket's memcg is a better
|
|
* decision in this case.
|
|
*/
|
|
if (sk->sk_cgrp) {
|
|
BUG_ON(mem_cgroup_is_root(sk->sk_cgrp->memcg));
|
|
css_get(&sk->sk_cgrp->memcg->css);
|
|
return;
|
|
}
|
|
|
|
rcu_read_lock();
|
|
memcg = mem_cgroup_from_task(current);
|
|
cg_proto = sk->sk_prot->proto_cgroup(memcg);
|
|
if (!mem_cgroup_is_root(memcg) &&
|
|
memcg_proto_active(cg_proto) && css_tryget(&memcg->css)) {
|
|
sk->sk_cgrp = cg_proto;
|
|
}
|
|
rcu_read_unlock();
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(sock_update_memcg);
|
|
|
|
void sock_release_memcg(struct sock *sk)
|
|
{
|
|
if (mem_cgroup_sockets_enabled && sk->sk_cgrp) {
|
|
struct mem_cgroup *memcg;
|
|
WARN_ON(!sk->sk_cgrp->memcg);
|
|
memcg = sk->sk_cgrp->memcg;
|
|
css_put(&sk->sk_cgrp->memcg->css);
|
|
}
|
|
}
|
|
|
|
struct cg_proto *tcp_proto_cgroup(struct mem_cgroup *memcg)
|
|
{
|
|
if (!memcg || mem_cgroup_is_root(memcg))
|
|
return NULL;
|
|
|
|
return &memcg->tcp_mem.cg_proto;
|
|
}
|
|
EXPORT_SYMBOL(tcp_proto_cgroup);
|
|
|
|
static void disarm_sock_keys(struct mem_cgroup *memcg)
|
|
{
|
|
if (!memcg_proto_activated(&memcg->tcp_mem.cg_proto))
|
|
return;
|
|
static_key_slow_dec(&memcg_socket_limit_enabled);
|
|
}
|
|
#else
|
|
static void disarm_sock_keys(struct mem_cgroup *memcg)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
#ifdef CONFIG_MEMCG_KMEM
|
|
/*
|
|
* This will be the memcg's index in each cache's ->memcg_params->memcg_caches.
|
|
* There are two main reasons for not using the css_id for this:
|
|
* 1) this works better in sparse environments, where we have a lot of memcgs,
|
|
* but only a few kmem-limited. Or also, if we have, for instance, 200
|
|
* memcgs, and none but the 200th is kmem-limited, we'd have to have a
|
|
* 200 entry array for that.
|
|
*
|
|
* 2) In order not to violate the cgroup API, we would like to do all memory
|
|
* allocation in ->create(). At that point, we haven't yet allocated the
|
|
* css_id. Having a separate index prevents us from messing with the cgroup
|
|
* core for this
|
|
*
|
|
* The current size of the caches array is stored in
|
|
* memcg_limited_groups_array_size. It will double each time we have to
|
|
* increase it.
|
|
*/
|
|
static DEFINE_IDA(kmem_limited_groups);
|
|
int memcg_limited_groups_array_size;
|
|
|
|
/*
|
|
* MIN_SIZE is different than 1, because we would like to avoid going through
|
|
* the alloc/free process all the time. In a small machine, 4 kmem-limited
|
|
* cgroups is a reasonable guess. In the future, it could be a parameter or
|
|
* tunable, but that is strictly not necessary.
|
|
*
|
|
* MAX_SIZE should be as large as the number of css_ids. Ideally, we could get
|
|
* this constant directly from cgroup, but it is understandable that this is
|
|
* better kept as an internal representation in cgroup.c. In any case, the
|
|
* css_id space is not getting any smaller, and we don't have to necessarily
|
|
* increase ours as well if it increases.
|
|
*/
|
|
#define MEMCG_CACHES_MIN_SIZE 4
|
|
#define MEMCG_CACHES_MAX_SIZE 65535
|
|
|
|
/*
|
|
* A lot of the calls to the cache allocation functions are expected to be
|
|
* inlined by the compiler. Since the calls to memcg_kmem_get_cache are
|
|
* conditional to this static branch, we'll have to allow modules that does
|
|
* kmem_cache_alloc and the such to see this symbol as well
|
|
*/
|
|
struct static_key memcg_kmem_enabled_key;
|
|
EXPORT_SYMBOL(memcg_kmem_enabled_key);
|
|
|
|
static void disarm_kmem_keys(struct mem_cgroup *memcg)
|
|
{
|
|
if (memcg_kmem_is_active(memcg)) {
|
|
static_key_slow_dec(&memcg_kmem_enabled_key);
|
|
ida_simple_remove(&kmem_limited_groups, memcg->kmemcg_id);
|
|
}
|
|
/*
|
|
* This check can't live in kmem destruction function,
|
|
* since the charges will outlive the cgroup
|
|
*/
|
|
WARN_ON(res_counter_read_u64(&memcg->kmem, RES_USAGE) != 0);
|
|
}
|
|
#else
|
|
static void disarm_kmem_keys(struct mem_cgroup *memcg)
|
|
{
|
|
}
|
|
#endif /* CONFIG_MEMCG_KMEM */
|
|
|
|
static void disarm_static_keys(struct mem_cgroup *memcg)
|
|
{
|
|
disarm_sock_keys(memcg);
|
|
disarm_kmem_keys(memcg);
|
|
}
|
|
|
|
static void drain_all_stock_async(struct mem_cgroup *memcg);
|
|
|
|
static struct mem_cgroup_per_zone *
|
|
mem_cgroup_zoneinfo(struct mem_cgroup *memcg, int nid, int zid)
|
|
{
|
|
VM_BUG_ON((unsigned)nid >= nr_node_ids);
|
|
return &memcg->nodeinfo[nid]->zoneinfo[zid];
|
|
}
|
|
|
|
struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *memcg)
|
|
{
|
|
return &memcg->css;
|
|
}
|
|
|
|
static struct mem_cgroup_per_zone *
|
|
page_cgroup_zoneinfo(struct mem_cgroup *memcg, struct page *page)
|
|
{
|
|
int nid = page_to_nid(page);
|
|
int zid = page_zonenum(page);
|
|
|
|
return mem_cgroup_zoneinfo(memcg, nid, zid);
|
|
}
|
|
|
|
static struct mem_cgroup_tree_per_zone *
|
|
soft_limit_tree_node_zone(int nid, int zid)
|
|
{
|
|
return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid];
|
|
}
|
|
|
|
static struct mem_cgroup_tree_per_zone *
|
|
soft_limit_tree_from_page(struct page *page)
|
|
{
|
|
int nid = page_to_nid(page);
|
|
int zid = page_zonenum(page);
|
|
|
|
return &soft_limit_tree.rb_tree_per_node[nid]->rb_tree_per_zone[zid];
|
|
}
|
|
|
|
static void
|
|
__mem_cgroup_insert_exceeded(struct mem_cgroup *memcg,
|
|
struct mem_cgroup_per_zone *mz,
|
|
struct mem_cgroup_tree_per_zone *mctz,
|
|
unsigned long long new_usage_in_excess)
|
|
{
|
|
struct rb_node **p = &mctz->rb_root.rb_node;
|
|
struct rb_node *parent = NULL;
|
|
struct mem_cgroup_per_zone *mz_node;
|
|
|
|
if (mz->on_tree)
|
|
return;
|
|
|
|
mz->usage_in_excess = new_usage_in_excess;
|
|
if (!mz->usage_in_excess)
|
|
return;
|
|
while (*p) {
|
|
parent = *p;
|
|
mz_node = rb_entry(parent, struct mem_cgroup_per_zone,
|
|
tree_node);
|
|
if (mz->usage_in_excess < mz_node->usage_in_excess)
|
|
p = &(*p)->rb_left;
|
|
/*
|
|
* We can't avoid mem cgroups that are over their soft
|
|
* limit by the same amount
|
|
*/
|
|
else if (mz->usage_in_excess >= mz_node->usage_in_excess)
|
|
p = &(*p)->rb_right;
|
|
}
|
|
rb_link_node(&mz->tree_node, parent, p);
|
|
rb_insert_color(&mz->tree_node, &mctz->rb_root);
|
|
mz->on_tree = true;
|
|
}
|
|
|
|
static void
|
|
__mem_cgroup_remove_exceeded(struct mem_cgroup *memcg,
|
|
struct mem_cgroup_per_zone *mz,
|
|
struct mem_cgroup_tree_per_zone *mctz)
|
|
{
|
|
if (!mz->on_tree)
|
|
return;
|
|
rb_erase(&mz->tree_node, &mctz->rb_root);
|
|
mz->on_tree = false;
|
|
}
|
|
|
|
static void
|
|
mem_cgroup_remove_exceeded(struct mem_cgroup *memcg,
|
|
struct mem_cgroup_per_zone *mz,
|
|
struct mem_cgroup_tree_per_zone *mctz)
|
|
{
|
|
spin_lock(&mctz->lock);
|
|
__mem_cgroup_remove_exceeded(memcg, mz, mctz);
|
|
spin_unlock(&mctz->lock);
|
|
}
|
|
|
|
|
|
static void mem_cgroup_update_tree(struct mem_cgroup *memcg, struct page *page)
|
|
{
|
|
unsigned long long excess;
|
|
struct mem_cgroup_per_zone *mz;
|
|
struct mem_cgroup_tree_per_zone *mctz;
|
|
int nid = page_to_nid(page);
|
|
int zid = page_zonenum(page);
|
|
mctz = soft_limit_tree_from_page(page);
|
|
|
|
/*
|
|
* Necessary to update all ancestors when hierarchy is used.
|
|
* because their event counter is not touched.
|
|
*/
|
|
for (; memcg; memcg = parent_mem_cgroup(memcg)) {
|
|
mz = mem_cgroup_zoneinfo(memcg, nid, zid);
|
|
excess = res_counter_soft_limit_excess(&memcg->res);
|
|
/*
|
|
* We have to update the tree if mz is on RB-tree or
|
|
* mem is over its softlimit.
|
|
*/
|
|
if (excess || mz->on_tree) {
|
|
spin_lock(&mctz->lock);
|
|
/* if on-tree, remove it */
|
|
if (mz->on_tree)
|
|
__mem_cgroup_remove_exceeded(memcg, mz, mctz);
|
|
/*
|
|
* Insert again. mz->usage_in_excess will be updated.
|
|
* If excess is 0, no tree ops.
|
|
*/
|
|
__mem_cgroup_insert_exceeded(memcg, mz, mctz, excess);
|
|
spin_unlock(&mctz->lock);
|
|
}
|
|
}
|
|
}
|
|
|
|
static void mem_cgroup_remove_from_trees(struct mem_cgroup *memcg)
|
|
{
|
|
int node, zone;
|
|
struct mem_cgroup_per_zone *mz;
|
|
struct mem_cgroup_tree_per_zone *mctz;
|
|
|
|
for_each_node(node) {
|
|
for (zone = 0; zone < MAX_NR_ZONES; zone++) {
|
|
mz = mem_cgroup_zoneinfo(memcg, node, zone);
|
|
mctz = soft_limit_tree_node_zone(node, zone);
|
|
mem_cgroup_remove_exceeded(memcg, mz, mctz);
|
|
}
|
|
}
|
|
}
|
|
|
|
static struct mem_cgroup_per_zone *
|
|
__mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz)
|
|
{
|
|
struct rb_node *rightmost = NULL;
|
|
struct mem_cgroup_per_zone *mz;
|
|
|
|
retry:
|
|
mz = NULL;
|
|
rightmost = rb_last(&mctz->rb_root);
|
|
if (!rightmost)
|
|
goto done; /* Nothing to reclaim from */
|
|
|
|
mz = rb_entry(rightmost, struct mem_cgroup_per_zone, tree_node);
|
|
/*
|
|
* Remove the node now but someone else can add it back,
|
|
* we will to add it back at the end of reclaim to its correct
|
|
* position in the tree.
|
|
*/
|
|
__mem_cgroup_remove_exceeded(mz->memcg, mz, mctz);
|
|
if (!res_counter_soft_limit_excess(&mz->memcg->res) ||
|
|
!css_tryget(&mz->memcg->css))
|
|
goto retry;
|
|
done:
|
|
return mz;
|
|
}
|
|
|
|
static struct mem_cgroup_per_zone *
|
|
mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz)
|
|
{
|
|
struct mem_cgroup_per_zone *mz;
|
|
|
|
spin_lock(&mctz->lock);
|
|
mz = __mem_cgroup_largest_soft_limit_node(mctz);
|
|
spin_unlock(&mctz->lock);
|
|
return mz;
|
|
}
|
|
|
|
/*
|
|
* Implementation Note: reading percpu statistics for memcg.
|
|
*
|
|
* Both of vmstat[] and percpu_counter has threshold and do periodic
|
|
* synchronization to implement "quick" read. There are trade-off between
|
|
* reading cost and precision of value. Then, we may have a chance to implement
|
|
* a periodic synchronizion of counter in memcg's counter.
|
|
*
|
|
* But this _read() function is used for user interface now. The user accounts
|
|
* memory usage by memory cgroup and he _always_ requires exact value because
|
|
* he accounts memory. Even if we provide quick-and-fuzzy read, we always
|
|
* have to visit all online cpus and make sum. So, for now, unnecessary
|
|
* synchronization is not implemented. (just implemented for cpu hotplug)
|
|
*
|
|
* If there are kernel internal actions which can make use of some not-exact
|
|
* value, and reading all cpu value can be performance bottleneck in some
|
|
* common workload, threashold and synchonization as vmstat[] should be
|
|
* implemented.
|
|
*/
|
|
static long mem_cgroup_read_stat(struct mem_cgroup *memcg,
|
|
enum mem_cgroup_stat_index idx)
|
|
{
|
|
long val = 0;
|
|
int cpu;
|
|
|
|
get_online_cpus();
|
|
for_each_online_cpu(cpu)
|
|
val += per_cpu(memcg->stat->count[idx], cpu);
|
|
#ifdef CONFIG_HOTPLUG_CPU
|
|
spin_lock(&memcg->pcp_counter_lock);
|
|
val += memcg->nocpu_base.count[idx];
|
|
spin_unlock(&memcg->pcp_counter_lock);
|
|
#endif
|
|
put_online_cpus();
|
|
return val;
|
|
}
|
|
|
|
static void mem_cgroup_swap_statistics(struct mem_cgroup *memcg,
|
|
bool charge)
|
|
{
|
|
int val = (charge) ? 1 : -1;
|
|
this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_SWAP], val);
|
|
}
|
|
|
|
static unsigned long mem_cgroup_read_events(struct mem_cgroup *memcg,
|
|
enum mem_cgroup_events_index idx)
|
|
{
|
|
unsigned long val = 0;
|
|
int cpu;
|
|
|
|
get_online_cpus();
|
|
for_each_online_cpu(cpu)
|
|
val += per_cpu(memcg->stat->events[idx], cpu);
|
|
#ifdef CONFIG_HOTPLUG_CPU
|
|
spin_lock(&memcg->pcp_counter_lock);
|
|
val += memcg->nocpu_base.events[idx];
|
|
spin_unlock(&memcg->pcp_counter_lock);
|
|
#endif
|
|
put_online_cpus();
|
|
return val;
|
|
}
|
|
|
|
static void mem_cgroup_charge_statistics(struct mem_cgroup *memcg,
|
|
struct page *page,
|
|
bool anon, int nr_pages)
|
|
{
|
|
preempt_disable();
|
|
|
|
/*
|
|
* Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is
|
|
* counted as CACHE even if it's on ANON LRU.
|
|
*/
|
|
if (anon)
|
|
__this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_RSS],
|
|
nr_pages);
|
|
else
|
|
__this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_CACHE],
|
|
nr_pages);
|
|
|
|
if (PageTransHuge(page))
|
|
__this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_RSS_HUGE],
|
|
nr_pages);
|
|
|
|
/* pagein of a big page is an event. So, ignore page size */
|
|
if (nr_pages > 0)
|
|
__this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGIN]);
|
|
else {
|
|
__this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGPGOUT]);
|
|
nr_pages = -nr_pages; /* for event */
|
|
}
|
|
|
|
__this_cpu_add(memcg->stat->nr_page_events, nr_pages);
|
|
|
|
preempt_enable();
|
|
}
|
|
|
|
unsigned long
|
|
mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list lru)
|
|
{
|
|
struct mem_cgroup_per_zone *mz;
|
|
|
|
mz = container_of(lruvec, struct mem_cgroup_per_zone, lruvec);
|
|
return mz->lru_size[lru];
|
|
}
|
|
|
|
static unsigned long
|
|
mem_cgroup_zone_nr_lru_pages(struct mem_cgroup *memcg, int nid, int zid,
|
|
unsigned int lru_mask)
|
|
{
|
|
struct mem_cgroup_per_zone *mz;
|
|
enum lru_list lru;
|
|
unsigned long ret = 0;
|
|
|
|
mz = mem_cgroup_zoneinfo(memcg, nid, zid);
|
|
|
|
for_each_lru(lru) {
|
|
if (BIT(lru) & lru_mask)
|
|
ret += mz->lru_size[lru];
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static unsigned long
|
|
mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg,
|
|
int nid, unsigned int lru_mask)
|
|
{
|
|
u64 total = 0;
|
|
int zid;
|
|
|
|
for (zid = 0; zid < MAX_NR_ZONES; zid++)
|
|
total += mem_cgroup_zone_nr_lru_pages(memcg,
|
|
nid, zid, lru_mask);
|
|
|
|
return total;
|
|
}
|
|
|
|
static unsigned long mem_cgroup_nr_lru_pages(struct mem_cgroup *memcg,
|
|
unsigned int lru_mask)
|
|
{
|
|
int nid;
|
|
u64 total = 0;
|
|
|
|
for_each_node_state(nid, N_MEMORY)
|
|
total += mem_cgroup_node_nr_lru_pages(memcg, nid, lru_mask);
|
|
return total;
|
|
}
|
|
|
|
static bool mem_cgroup_event_ratelimit(struct mem_cgroup *memcg,
|
|
enum mem_cgroup_events_target target)
|
|
{
|
|
unsigned long val, next;
|
|
|
|
val = __this_cpu_read(memcg->stat->nr_page_events);
|
|
next = __this_cpu_read(memcg->stat->targets[target]);
|
|
/* from time_after() in jiffies.h */
|
|
if ((long)next - (long)val < 0) {
|
|
switch (target) {
|
|
case MEM_CGROUP_TARGET_THRESH:
|
|
next = val + THRESHOLDS_EVENTS_TARGET;
|
|
break;
|
|
case MEM_CGROUP_TARGET_SOFTLIMIT:
|
|
next = val + SOFTLIMIT_EVENTS_TARGET;
|
|
break;
|
|
case MEM_CGROUP_TARGET_NUMAINFO:
|
|
next = val + NUMAINFO_EVENTS_TARGET;
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
__this_cpu_write(memcg->stat->targets[target], next);
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Check events in order.
|
|
*
|
|
*/
|
|
static void memcg_check_events(struct mem_cgroup *memcg, struct page *page)
|
|
{
|
|
preempt_disable();
|
|
/* threshold event is triggered in finer grain than soft limit */
|
|
if (unlikely(mem_cgroup_event_ratelimit(memcg,
|
|
MEM_CGROUP_TARGET_THRESH))) {
|
|
bool do_softlimit;
|
|
bool do_numainfo __maybe_unused;
|
|
|
|
do_softlimit = mem_cgroup_event_ratelimit(memcg,
|
|
MEM_CGROUP_TARGET_SOFTLIMIT);
|
|
#if MAX_NUMNODES > 1
|
|
do_numainfo = mem_cgroup_event_ratelimit(memcg,
|
|
MEM_CGROUP_TARGET_NUMAINFO);
|
|
#endif
|
|
preempt_enable();
|
|
|
|
mem_cgroup_threshold(memcg);
|
|
if (unlikely(do_softlimit))
|
|
mem_cgroup_update_tree(memcg, page);
|
|
#if MAX_NUMNODES > 1
|
|
if (unlikely(do_numainfo))
|
|
atomic_inc(&memcg->numainfo_events);
|
|
#endif
|
|
} else
|
|
preempt_enable();
|
|
}
|
|
|
|
struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p)
|
|
{
|
|
/*
|
|
* mm_update_next_owner() may clear mm->owner to NULL
|
|
* if it races with swapoff, page migration, etc.
|
|
* So this can be called with p == NULL.
|
|
*/
|
|
if (unlikely(!p))
|
|
return NULL;
|
|
|
|
return mem_cgroup_from_css(task_css(p, mem_cgroup_subsys_id));
|
|
}
|
|
|
|
struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm)
|
|
{
|
|
struct mem_cgroup *memcg = NULL;
|
|
|
|
if (!mm)
|
|
return NULL;
|
|
/*
|
|
* Because we have no locks, mm->owner's may be being moved to other
|
|
* cgroup. We use css_tryget() here even if this looks
|
|
* pessimistic (rather than adding locks here).
|
|
*/
|
|
rcu_read_lock();
|
|
do {
|
|
memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
|
|
if (unlikely(!memcg))
|
|
break;
|
|
} while (!css_tryget(&memcg->css));
|
|
rcu_read_unlock();
|
|
return memcg;
|
|
}
|
|
|
|
/*
|
|
* Returns a next (in a pre-order walk) alive memcg (with elevated css
|
|
* ref. count) or NULL if the whole root's subtree has been visited.
|
|
*
|
|
* helper function to be used by mem_cgroup_iter
|
|
*/
|
|
static struct mem_cgroup *__mem_cgroup_iter_next(struct mem_cgroup *root,
|
|
struct mem_cgroup *last_visited)
|
|
{
|
|
struct cgroup_subsys_state *prev_css, *next_css;
|
|
|
|
prev_css = last_visited ? &last_visited->css : NULL;
|
|
skip_node:
|
|
next_css = css_next_descendant_pre(prev_css, &root->css);
|
|
|
|
/*
|
|
* Even if we found a group we have to make sure it is
|
|
* alive. css && !memcg means that the groups should be
|
|
* skipped and we should continue the tree walk.
|
|
* last_visited css is safe to use because it is
|
|
* protected by css_get and the tree walk is rcu safe.
|
|
*/
|
|
if (next_css) {
|
|
struct mem_cgroup *mem = mem_cgroup_from_css(next_css);
|
|
|
|
if (css_tryget(&mem->css))
|
|
return mem;
|
|
else {
|
|
prev_css = next_css;
|
|
goto skip_node;
|
|
}
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static void mem_cgroup_iter_invalidate(struct mem_cgroup *root)
|
|
{
|
|
/*
|
|
* When a group in the hierarchy below root is destroyed, the
|
|
* hierarchy iterator can no longer be trusted since it might
|
|
* have pointed to the destroyed group. Invalidate it.
|
|
*/
|
|
atomic_inc(&root->dead_count);
|
|
}
|
|
|
|
static struct mem_cgroup *
|
|
mem_cgroup_iter_load(struct mem_cgroup_reclaim_iter *iter,
|
|
struct mem_cgroup *root,
|
|
int *sequence)
|
|
{
|
|
struct mem_cgroup *position = NULL;
|
|
/*
|
|
* A cgroup destruction happens in two stages: offlining and
|
|
* release. They are separated by a RCU grace period.
|
|
*
|
|
* If the iterator is valid, we may still race with an
|
|
* offlining. The RCU lock ensures the object won't be
|
|
* released, tryget will fail if we lost the race.
|
|
*/
|
|
*sequence = atomic_read(&root->dead_count);
|
|
if (iter->last_dead_count == *sequence) {
|
|
smp_rmb();
|
|
position = iter->last_visited;
|
|
if (position && !css_tryget(&position->css))
|
|
position = NULL;
|
|
}
|
|
return position;
|
|
}
|
|
|
|
static void mem_cgroup_iter_update(struct mem_cgroup_reclaim_iter *iter,
|
|
struct mem_cgroup *last_visited,
|
|
struct mem_cgroup *new_position,
|
|
int sequence)
|
|
{
|
|
if (last_visited)
|
|
css_put(&last_visited->css);
|
|
/*
|
|
* We store the sequence count from the time @last_visited was
|
|
* loaded successfully instead of rereading it here so that we
|
|
* don't lose destruction events in between. We could have
|
|
* raced with the destruction of @new_position after all.
|
|
*/
|
|
iter->last_visited = new_position;
|
|
smp_wmb();
|
|
iter->last_dead_count = sequence;
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_iter - iterate over memory cgroup hierarchy
|
|
* @root: hierarchy root
|
|
* @prev: previously returned memcg, NULL on first invocation
|
|
* @reclaim: cookie for shared reclaim walks, NULL for full walks
|
|
*
|
|
* Returns references to children of the hierarchy below @root, or
|
|
* @root itself, or %NULL after a full round-trip.
|
|
*
|
|
* Caller must pass the return value in @prev on subsequent
|
|
* invocations for reference counting, or use mem_cgroup_iter_break()
|
|
* to cancel a hierarchy walk before the round-trip is complete.
|
|
*
|
|
* Reclaimers can specify a zone and a priority level in @reclaim to
|
|
* divide up the memcgs in the hierarchy among all concurrent
|
|
* reclaimers operating on the same zone and priority.
|
|
*/
|
|
struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root,
|
|
struct mem_cgroup *prev,
|
|
struct mem_cgroup_reclaim_cookie *reclaim)
|
|
{
|
|
struct mem_cgroup *memcg = NULL;
|
|
struct mem_cgroup *last_visited = NULL;
|
|
|
|
if (mem_cgroup_disabled())
|
|
return NULL;
|
|
|
|
if (!root)
|
|
root = root_mem_cgroup;
|
|
|
|
if (prev && !reclaim)
|
|
last_visited = prev;
|
|
|
|
if (!root->use_hierarchy && root != root_mem_cgroup) {
|
|
if (prev)
|
|
goto out_css_put;
|
|
return root;
|
|
}
|
|
|
|
rcu_read_lock();
|
|
while (!memcg) {
|
|
struct mem_cgroup_reclaim_iter *uninitialized_var(iter);
|
|
int uninitialized_var(seq);
|
|
|
|
if (reclaim) {
|
|
int nid = zone_to_nid(reclaim->zone);
|
|
int zid = zone_idx(reclaim->zone);
|
|
struct mem_cgroup_per_zone *mz;
|
|
|
|
mz = mem_cgroup_zoneinfo(root, nid, zid);
|
|
iter = &mz->reclaim_iter[reclaim->priority];
|
|
if (prev && reclaim->generation != iter->generation) {
|
|
iter->last_visited = NULL;
|
|
goto out_unlock;
|
|
}
|
|
|
|
last_visited = mem_cgroup_iter_load(iter, root, &seq);
|
|
}
|
|
|
|
memcg = __mem_cgroup_iter_next(root, last_visited);
|
|
|
|
if (reclaim) {
|
|
mem_cgroup_iter_update(iter, last_visited, memcg, seq);
|
|
|
|
if (!memcg)
|
|
iter->generation++;
|
|
else if (!prev && memcg)
|
|
reclaim->generation = iter->generation;
|
|
}
|
|
|
|
if (prev && !memcg)
|
|
goto out_unlock;
|
|
}
|
|
out_unlock:
|
|
rcu_read_unlock();
|
|
out_css_put:
|
|
if (prev && prev != root)
|
|
css_put(&prev->css);
|
|
|
|
return memcg;
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_iter_break - abort a hierarchy walk prematurely
|
|
* @root: hierarchy root
|
|
* @prev: last visited hierarchy member as returned by mem_cgroup_iter()
|
|
*/
|
|
void mem_cgroup_iter_break(struct mem_cgroup *root,
|
|
struct mem_cgroup *prev)
|
|
{
|
|
if (!root)
|
|
root = root_mem_cgroup;
|
|
if (prev && prev != root)
|
|
css_put(&prev->css);
|
|
}
|
|
|
|
/*
|
|
* Iteration constructs for visiting all cgroups (under a tree). If
|
|
* loops are exited prematurely (break), mem_cgroup_iter_break() must
|
|
* be used for reference counting.
|
|
*/
|
|
#define for_each_mem_cgroup_tree(iter, root) \
|
|
for (iter = mem_cgroup_iter(root, NULL, NULL); \
|
|
iter != NULL; \
|
|
iter = mem_cgroup_iter(root, iter, NULL))
|
|
|
|
#define for_each_mem_cgroup(iter) \
|
|
for (iter = mem_cgroup_iter(NULL, NULL, NULL); \
|
|
iter != NULL; \
|
|
iter = mem_cgroup_iter(NULL, iter, NULL))
|
|
|
|
void __mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
|
|
rcu_read_lock();
|
|
memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));
|
|
if (unlikely(!memcg))
|
|
goto out;
|
|
|
|
switch (idx) {
|
|
case PGFAULT:
|
|
this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGFAULT]);
|
|
break;
|
|
case PGMAJFAULT:
|
|
this_cpu_inc(memcg->stat->events[MEM_CGROUP_EVENTS_PGMAJFAULT]);
|
|
break;
|
|
default:
|
|
BUG();
|
|
}
|
|
out:
|
|
rcu_read_unlock();
|
|
}
|
|
EXPORT_SYMBOL(__mem_cgroup_count_vm_event);
|
|
|
|
/**
|
|
* mem_cgroup_zone_lruvec - get the lru list vector for a zone and memcg
|
|
* @zone: zone of the wanted lruvec
|
|
* @memcg: memcg of the wanted lruvec
|
|
*
|
|
* Returns the lru list vector holding pages for the given @zone and
|
|
* @mem. This can be the global zone lruvec, if the memory controller
|
|
* is disabled.
|
|
*/
|
|
struct lruvec *mem_cgroup_zone_lruvec(struct zone *zone,
|
|
struct mem_cgroup *memcg)
|
|
{
|
|
struct mem_cgroup_per_zone *mz;
|
|
struct lruvec *lruvec;
|
|
|
|
if (mem_cgroup_disabled()) {
|
|
lruvec = &zone->lruvec;
|
|
goto out;
|
|
}
|
|
|
|
mz = mem_cgroup_zoneinfo(memcg, zone_to_nid(zone), zone_idx(zone));
|
|
lruvec = &mz->lruvec;
|
|
out:
|
|
/*
|
|
* Since a node can be onlined after the mem_cgroup was created,
|
|
* we have to be prepared to initialize lruvec->zone here;
|
|
* and if offlined then reonlined, we need to reinitialize it.
|
|
*/
|
|
if (unlikely(lruvec->zone != zone))
|
|
lruvec->zone = zone;
|
|
return lruvec;
|
|
}
|
|
|
|
/*
|
|
* Following LRU functions are allowed to be used without PCG_LOCK.
|
|
* Operations are called by routine of global LRU independently from memcg.
|
|
* What we have to take care of here is validness of pc->mem_cgroup.
|
|
*
|
|
* Changes to pc->mem_cgroup happens when
|
|
* 1. charge
|
|
* 2. moving account
|
|
* In typical case, "charge" is done before add-to-lru. Exception is SwapCache.
|
|
* It is added to LRU before charge.
|
|
* If PCG_USED bit is not set, page_cgroup is not added to this private LRU.
|
|
* When moving account, the page is not on LRU. It's isolated.
|
|
*/
|
|
|
|
/**
|
|
* mem_cgroup_page_lruvec - return lruvec for adding an lru page
|
|
* @page: the page
|
|
* @zone: zone of the page
|
|
*/
|
|
struct lruvec *mem_cgroup_page_lruvec(struct page *page, struct zone *zone)
|
|
{
|
|
struct mem_cgroup_per_zone *mz;
|
|
struct mem_cgroup *memcg;
|
|
struct page_cgroup *pc;
|
|
struct lruvec *lruvec;
|
|
|
|
if (mem_cgroup_disabled()) {
|
|
lruvec = &zone->lruvec;
|
|
goto out;
|
|
}
|
|
|
|
pc = lookup_page_cgroup(page);
|
|
memcg = pc->mem_cgroup;
|
|
|
|
/*
|
|
* Surreptitiously switch any uncharged offlist page to root:
|
|
* an uncharged page off lru does nothing to secure
|
|
* its former mem_cgroup from sudden removal.
|
|
*
|
|
* Our caller holds lru_lock, and PageCgroupUsed is updated
|
|
* under page_cgroup lock: between them, they make all uses
|
|
* of pc->mem_cgroup safe.
|
|
*/
|
|
if (!PageLRU(page) && !PageCgroupUsed(pc) && memcg != root_mem_cgroup)
|
|
pc->mem_cgroup = memcg = root_mem_cgroup;
|
|
|
|
mz = page_cgroup_zoneinfo(memcg, page);
|
|
lruvec = &mz->lruvec;
|
|
out:
|
|
/*
|
|
* Since a node can be onlined after the mem_cgroup was created,
|
|
* we have to be prepared to initialize lruvec->zone here;
|
|
* and if offlined then reonlined, we need to reinitialize it.
|
|
*/
|
|
if (unlikely(lruvec->zone != zone))
|
|
lruvec->zone = zone;
|
|
return lruvec;
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_update_lru_size - account for adding or removing an lru page
|
|
* @lruvec: mem_cgroup per zone lru vector
|
|
* @lru: index of lru list the page is sitting on
|
|
* @nr_pages: positive when adding or negative when removing
|
|
*
|
|
* This function must be called when a page is added to or removed from an
|
|
* lru list.
|
|
*/
|
|
void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru,
|
|
int nr_pages)
|
|
{
|
|
struct mem_cgroup_per_zone *mz;
|
|
unsigned long *lru_size;
|
|
|
|
if (mem_cgroup_disabled())
|
|
return;
|
|
|
|
mz = container_of(lruvec, struct mem_cgroup_per_zone, lruvec);
|
|
lru_size = mz->lru_size + lru;
|
|
*lru_size += nr_pages;
|
|
VM_BUG_ON((long)(*lru_size) < 0);
|
|
}
|
|
|
|
/*
|
|
* Checks whether given mem is same or in the root_mem_cgroup's
|
|
* hierarchy subtree
|
|
*/
|
|
bool __mem_cgroup_same_or_subtree(const struct mem_cgroup *root_memcg,
|
|
struct mem_cgroup *memcg)
|
|
{
|
|
if (root_memcg == memcg)
|
|
return true;
|
|
if (!root_memcg->use_hierarchy || !memcg)
|
|
return false;
|
|
return css_is_ancestor(&memcg->css, &root_memcg->css);
|
|
}
|
|
|
|
static bool mem_cgroup_same_or_subtree(const struct mem_cgroup *root_memcg,
|
|
struct mem_cgroup *memcg)
|
|
{
|
|
bool ret;
|
|
|
|
rcu_read_lock();
|
|
ret = __mem_cgroup_same_or_subtree(root_memcg, memcg);
|
|
rcu_read_unlock();
|
|
return ret;
|
|
}
|
|
|
|
bool task_in_mem_cgroup(struct task_struct *task,
|
|
const struct mem_cgroup *memcg)
|
|
{
|
|
struct mem_cgroup *curr = NULL;
|
|
struct task_struct *p;
|
|
bool ret;
|
|
|
|
p = find_lock_task_mm(task);
|
|
if (p) {
|
|
curr = try_get_mem_cgroup_from_mm(p->mm);
|
|
task_unlock(p);
|
|
} else {
|
|
/*
|
|
* All threads may have already detached their mm's, but the oom
|
|
* killer still needs to detect if they have already been oom
|
|
* killed to prevent needlessly killing additional tasks.
|
|
*/
|
|
rcu_read_lock();
|
|
curr = mem_cgroup_from_task(task);
|
|
if (curr)
|
|
css_get(&curr->css);
|
|
rcu_read_unlock();
|
|
}
|
|
if (!curr)
|
|
return false;
|
|
/*
|
|
* We should check use_hierarchy of "memcg" not "curr". Because checking
|
|
* use_hierarchy of "curr" here make this function true if hierarchy is
|
|
* enabled in "curr" and "curr" is a child of "memcg" in *cgroup*
|
|
* hierarchy(even if use_hierarchy is disabled in "memcg").
|
|
*/
|
|
ret = mem_cgroup_same_or_subtree(memcg, curr);
|
|
css_put(&curr->css);
|
|
return ret;
|
|
}
|
|
|
|
int mem_cgroup_inactive_anon_is_low(struct lruvec *lruvec)
|
|
{
|
|
unsigned long inactive_ratio;
|
|
unsigned long inactive;
|
|
unsigned long active;
|
|
unsigned long gb;
|
|
|
|
inactive = mem_cgroup_get_lru_size(lruvec, LRU_INACTIVE_ANON);
|
|
active = mem_cgroup_get_lru_size(lruvec, LRU_ACTIVE_ANON);
|
|
|
|
gb = (inactive + active) >> (30 - PAGE_SHIFT);
|
|
if (gb)
|
|
inactive_ratio = int_sqrt(10 * gb);
|
|
else
|
|
inactive_ratio = 1;
|
|
|
|
return inactive * inactive_ratio < active;
|
|
}
|
|
|
|
#define mem_cgroup_from_res_counter(counter, member) \
|
|
container_of(counter, struct mem_cgroup, member)
|
|
|
|
/**
|
|
* mem_cgroup_margin - calculate chargeable space of a memory cgroup
|
|
* @memcg: the memory cgroup
|
|
*
|
|
* Returns the maximum amount of memory @mem can be charged with, in
|
|
* pages.
|
|
*/
|
|
static unsigned long mem_cgroup_margin(struct mem_cgroup *memcg)
|
|
{
|
|
unsigned long long margin;
|
|
|
|
margin = res_counter_margin(&memcg->res);
|
|
if (do_swap_account)
|
|
margin = min(margin, res_counter_margin(&memcg->memsw));
|
|
return margin >> PAGE_SHIFT;
|
|
}
|
|
|
|
int mem_cgroup_swappiness(struct mem_cgroup *memcg)
|
|
{
|
|
/* root ? */
|
|
if (!css_parent(&memcg->css))
|
|
return vm_swappiness;
|
|
|
|
return memcg->swappiness;
|
|
}
|
|
|
|
/*
|
|
* memcg->moving_account is used for checking possibility that some thread is
|
|
* calling move_account(). When a thread on CPU-A starts moving pages under
|
|
* a memcg, other threads should check memcg->moving_account under
|
|
* rcu_read_lock(), like this:
|
|
*
|
|
* CPU-A CPU-B
|
|
* rcu_read_lock()
|
|
* memcg->moving_account+1 if (memcg->mocing_account)
|
|
* take heavy locks.
|
|
* synchronize_rcu() update something.
|
|
* rcu_read_unlock()
|
|
* start move here.
|
|
*/
|
|
|
|
/* for quick checking without looking up memcg */
|
|
atomic_t memcg_moving __read_mostly;
|
|
|
|
static void mem_cgroup_start_move(struct mem_cgroup *memcg)
|
|
{
|
|
atomic_inc(&memcg_moving);
|
|
atomic_inc(&memcg->moving_account);
|
|
synchronize_rcu();
|
|
}
|
|
|
|
static void mem_cgroup_end_move(struct mem_cgroup *memcg)
|
|
{
|
|
/*
|
|
* Now, mem_cgroup_clear_mc() may call this function with NULL.
|
|
* We check NULL in callee rather than caller.
|
|
*/
|
|
if (memcg) {
|
|
atomic_dec(&memcg_moving);
|
|
atomic_dec(&memcg->moving_account);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 2 routines for checking "mem" is under move_account() or not.
|
|
*
|
|
* mem_cgroup_stolen() - checking whether a cgroup is mc.from or not. This
|
|
* is used for avoiding races in accounting. If true,
|
|
* pc->mem_cgroup may be overwritten.
|
|
*
|
|
* mem_cgroup_under_move() - checking a cgroup is mc.from or mc.to or
|
|
* under hierarchy of moving cgroups. This is for
|
|
* waiting at hith-memory prressure caused by "move".
|
|
*/
|
|
|
|
static bool mem_cgroup_stolen(struct mem_cgroup *memcg)
|
|
{
|
|
VM_BUG_ON(!rcu_read_lock_held());
|
|
return atomic_read(&memcg->moving_account) > 0;
|
|
}
|
|
|
|
static bool mem_cgroup_under_move(struct mem_cgroup *memcg)
|
|
{
|
|
struct mem_cgroup *from;
|
|
struct mem_cgroup *to;
|
|
bool ret = false;
|
|
/*
|
|
* Unlike task_move routines, we access mc.to, mc.from not under
|
|
* mutual exclusion by cgroup_mutex. Here, we take spinlock instead.
|
|
*/
|
|
spin_lock(&mc.lock);
|
|
from = mc.from;
|
|
to = mc.to;
|
|
if (!from)
|
|
goto unlock;
|
|
|
|
ret = mem_cgroup_same_or_subtree(memcg, from)
|
|
|| mem_cgroup_same_or_subtree(memcg, to);
|
|
unlock:
|
|
spin_unlock(&mc.lock);
|
|
return ret;
|
|
}
|
|
|
|
static bool mem_cgroup_wait_acct_move(struct mem_cgroup *memcg)
|
|
{
|
|
if (mc.moving_task && current != mc.moving_task) {
|
|
if (mem_cgroup_under_move(memcg)) {
|
|
DEFINE_WAIT(wait);
|
|
prepare_to_wait(&mc.waitq, &wait, TASK_INTERRUPTIBLE);
|
|
/* moving charge context might have finished. */
|
|
if (mc.moving_task)
|
|
schedule();
|
|
finish_wait(&mc.waitq, &wait);
|
|
return true;
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Take this lock when
|
|
* - a code tries to modify page's memcg while it's USED.
|
|
* - a code tries to modify page state accounting in a memcg.
|
|
* see mem_cgroup_stolen(), too.
|
|
*/
|
|
static void move_lock_mem_cgroup(struct mem_cgroup *memcg,
|
|
unsigned long *flags)
|
|
{
|
|
spin_lock_irqsave(&memcg->move_lock, *flags);
|
|
}
|
|
|
|
static void move_unlock_mem_cgroup(struct mem_cgroup *memcg,
|
|
unsigned long *flags)
|
|
{
|
|
spin_unlock_irqrestore(&memcg->move_lock, *flags);
|
|
}
|
|
|
|
#define K(x) ((x) << (PAGE_SHIFT-10))
|
|
/**
|
|
* mem_cgroup_print_oom_info: Print OOM information relevant to memory controller.
|
|
* @memcg: The memory cgroup that went over limit
|
|
* @p: Task that is going to be killed
|
|
*
|
|
* NOTE: @memcg and @p's mem_cgroup can be different when hierarchy is
|
|
* enabled
|
|
*/
|
|
void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
|
|
{
|
|
struct cgroup *task_cgrp;
|
|
struct cgroup *mem_cgrp;
|
|
/*
|
|
* Need a buffer in BSS, can't rely on allocations. The code relies
|
|
* on the assumption that OOM is serialized for memory controller.
|
|
* If this assumption is broken, revisit this code.
|
|
*/
|
|
static char memcg_name[PATH_MAX];
|
|
int ret;
|
|
struct mem_cgroup *iter;
|
|
unsigned int i;
|
|
|
|
if (!p)
|
|
return;
|
|
|
|
rcu_read_lock();
|
|
|
|
mem_cgrp = memcg->css.cgroup;
|
|
task_cgrp = task_cgroup(p, mem_cgroup_subsys_id);
|
|
|
|
ret = cgroup_path(task_cgrp, memcg_name, PATH_MAX);
|
|
if (ret < 0) {
|
|
/*
|
|
* Unfortunately, we are unable to convert to a useful name
|
|
* But we'll still print out the usage information
|
|
*/
|
|
rcu_read_unlock();
|
|
goto done;
|
|
}
|
|
rcu_read_unlock();
|
|
|
|
pr_info("Task in %s killed", memcg_name);
|
|
|
|
rcu_read_lock();
|
|
ret = cgroup_path(mem_cgrp, memcg_name, PATH_MAX);
|
|
if (ret < 0) {
|
|
rcu_read_unlock();
|
|
goto done;
|
|
}
|
|
rcu_read_unlock();
|
|
|
|
/*
|
|
* Continues from above, so we don't need an KERN_ level
|
|
*/
|
|
pr_cont(" as a result of limit of %s\n", memcg_name);
|
|
done:
|
|
|
|
pr_info("memory: usage %llukB, limit %llukB, failcnt %llu\n",
|
|
res_counter_read_u64(&memcg->res, RES_USAGE) >> 10,
|
|
res_counter_read_u64(&memcg->res, RES_LIMIT) >> 10,
|
|
res_counter_read_u64(&memcg->res, RES_FAILCNT));
|
|
pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %llu\n",
|
|
res_counter_read_u64(&memcg->memsw, RES_USAGE) >> 10,
|
|
res_counter_read_u64(&memcg->memsw, RES_LIMIT) >> 10,
|
|
res_counter_read_u64(&memcg->memsw, RES_FAILCNT));
|
|
pr_info("kmem: usage %llukB, limit %llukB, failcnt %llu\n",
|
|
res_counter_read_u64(&memcg->kmem, RES_USAGE) >> 10,
|
|
res_counter_read_u64(&memcg->kmem, RES_LIMIT) >> 10,
|
|
res_counter_read_u64(&memcg->kmem, RES_FAILCNT));
|
|
|
|
for_each_mem_cgroup_tree(iter, memcg) {
|
|
pr_info("Memory cgroup stats");
|
|
|
|
rcu_read_lock();
|
|
ret = cgroup_path(iter->css.cgroup, memcg_name, PATH_MAX);
|
|
if (!ret)
|
|
pr_cont(" for %s", memcg_name);
|
|
rcu_read_unlock();
|
|
pr_cont(":");
|
|
|
|
for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) {
|
|
if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account)
|
|
continue;
|
|
pr_cont(" %s:%ldKB", mem_cgroup_stat_names[i],
|
|
K(mem_cgroup_read_stat(iter, i)));
|
|
}
|
|
|
|
for (i = 0; i < NR_LRU_LISTS; i++)
|
|
pr_cont(" %s:%luKB", mem_cgroup_lru_names[i],
|
|
K(mem_cgroup_nr_lru_pages(iter, BIT(i))));
|
|
|
|
pr_cont("\n");
|
|
}
|
|
}
|
|
|
|
/*
|
|
* This function returns the number of memcg under hierarchy tree. Returns
|
|
* 1(self count) if no children.
|
|
*/
|
|
static int mem_cgroup_count_children(struct mem_cgroup *memcg)
|
|
{
|
|
int num = 0;
|
|
struct mem_cgroup *iter;
|
|
|
|
for_each_mem_cgroup_tree(iter, memcg)
|
|
num++;
|
|
return num;
|
|
}
|
|
|
|
/*
|
|
* Return the memory (and swap, if configured) limit for a memcg.
|
|
*/
|
|
static u64 mem_cgroup_get_limit(struct mem_cgroup *memcg)
|
|
{
|
|
u64 limit;
|
|
|
|
limit = res_counter_read_u64(&memcg->res, RES_LIMIT);
|
|
|
|
/*
|
|
* Do not consider swap space if we cannot swap due to swappiness
|
|
*/
|
|
if (mem_cgroup_swappiness(memcg)) {
|
|
u64 memsw;
|
|
|
|
limit += total_swap_pages << PAGE_SHIFT;
|
|
memsw = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
|
|
|
|
/*
|
|
* If memsw is finite and limits the amount of swap space
|
|
* available to this memcg, return that limit.
|
|
*/
|
|
limit = min(limit, memsw);
|
|
}
|
|
|
|
return limit;
|
|
}
|
|
|
|
static void mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask,
|
|
int order)
|
|
{
|
|
struct mem_cgroup *iter;
|
|
unsigned long chosen_points = 0;
|
|
unsigned long totalpages;
|
|
unsigned int points = 0;
|
|
struct task_struct *chosen = NULL;
|
|
|
|
/*
|
|
* If current has a pending SIGKILL or is exiting, then automatically
|
|
* select it. The goal is to allow it to allocate so that it may
|
|
* quickly exit and free its memory.
|
|
*/
|
|
if (fatal_signal_pending(current) || current->flags & PF_EXITING) {
|
|
set_thread_flag(TIF_MEMDIE);
|
|
return;
|
|
}
|
|
|
|
check_panic_on_oom(CONSTRAINT_MEMCG, gfp_mask, order, NULL);
|
|
totalpages = mem_cgroup_get_limit(memcg) >> PAGE_SHIFT ? : 1;
|
|
for_each_mem_cgroup_tree(iter, memcg) {
|
|
struct css_task_iter it;
|
|
struct task_struct *task;
|
|
|
|
css_task_iter_start(&iter->css, &it);
|
|
while ((task = css_task_iter_next(&it))) {
|
|
switch (oom_scan_process_thread(task, totalpages, NULL,
|
|
false)) {
|
|
case OOM_SCAN_SELECT:
|
|
if (chosen)
|
|
put_task_struct(chosen);
|
|
chosen = task;
|
|
chosen_points = ULONG_MAX;
|
|
get_task_struct(chosen);
|
|
/* fall through */
|
|
case OOM_SCAN_CONTINUE:
|
|
continue;
|
|
case OOM_SCAN_ABORT:
|
|
css_task_iter_end(&it);
|
|
mem_cgroup_iter_break(memcg, iter);
|
|
if (chosen)
|
|
put_task_struct(chosen);
|
|
return;
|
|
case OOM_SCAN_OK:
|
|
break;
|
|
};
|
|
points = oom_badness(task, memcg, NULL, totalpages);
|
|
if (points > chosen_points) {
|
|
if (chosen)
|
|
put_task_struct(chosen);
|
|
chosen = task;
|
|
chosen_points = points;
|
|
get_task_struct(chosen);
|
|
}
|
|
}
|
|
css_task_iter_end(&it);
|
|
}
|
|
|
|
if (!chosen)
|
|
return;
|
|
points = chosen_points * 1000 / totalpages;
|
|
oom_kill_process(chosen, gfp_mask, order, points, totalpages, memcg,
|
|
NULL, "Memory cgroup out of memory");
|
|
}
|
|
|
|
static unsigned long mem_cgroup_reclaim(struct mem_cgroup *memcg,
|
|
gfp_t gfp_mask,
|
|
unsigned long flags)
|
|
{
|
|
unsigned long total = 0;
|
|
bool noswap = false;
|
|
int loop;
|
|
|
|
if (flags & MEM_CGROUP_RECLAIM_NOSWAP)
|
|
noswap = true;
|
|
if (!(flags & MEM_CGROUP_RECLAIM_SHRINK) && memcg->memsw_is_minimum)
|
|
noswap = true;
|
|
|
|
for (loop = 0; loop < MEM_CGROUP_MAX_RECLAIM_LOOPS; loop++) {
|
|
if (loop)
|
|
drain_all_stock_async(memcg);
|
|
total += try_to_free_mem_cgroup_pages(memcg, gfp_mask, noswap);
|
|
/*
|
|
* Allow limit shrinkers, which are triggered directly
|
|
* by userspace, to catch signals and stop reclaim
|
|
* after minimal progress, regardless of the margin.
|
|
*/
|
|
if (total && (flags & MEM_CGROUP_RECLAIM_SHRINK))
|
|
break;
|
|
if (mem_cgroup_margin(memcg))
|
|
break;
|
|
/*
|
|
* If nothing was reclaimed after two attempts, there
|
|
* may be no reclaimable pages in this hierarchy.
|
|
*/
|
|
if (loop && !total)
|
|
break;
|
|
}
|
|
return total;
|
|
}
|
|
|
|
/**
|
|
* test_mem_cgroup_node_reclaimable
|
|
* @memcg: the target memcg
|
|
* @nid: the node ID to be checked.
|
|
* @noswap : specify true here if the user wants flle only information.
|
|
*
|
|
* This function returns whether the specified memcg contains any
|
|
* reclaimable pages on a node. Returns true if there are any reclaimable
|
|
* pages in the node.
|
|
*/
|
|
static bool test_mem_cgroup_node_reclaimable(struct mem_cgroup *memcg,
|
|
int nid, bool noswap)
|
|
{
|
|
if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_FILE))
|
|
return true;
|
|
if (noswap || !total_swap_pages)
|
|
return false;
|
|
if (mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL_ANON))
|
|
return true;
|
|
return false;
|
|
|
|
}
|
|
#if MAX_NUMNODES > 1
|
|
|
|
/*
|
|
* Always updating the nodemask is not very good - even if we have an empty
|
|
* list or the wrong list here, we can start from some node and traverse all
|
|
* nodes based on the zonelist. So update the list loosely once per 10 secs.
|
|
*
|
|
*/
|
|
static void mem_cgroup_may_update_nodemask(struct mem_cgroup *memcg)
|
|
{
|
|
int nid;
|
|
/*
|
|
* numainfo_events > 0 means there was at least NUMAINFO_EVENTS_TARGET
|
|
* pagein/pageout changes since the last update.
|
|
*/
|
|
if (!atomic_read(&memcg->numainfo_events))
|
|
return;
|
|
if (atomic_inc_return(&memcg->numainfo_updating) > 1)
|
|
return;
|
|
|
|
/* make a nodemask where this memcg uses memory from */
|
|
memcg->scan_nodes = node_states[N_MEMORY];
|
|
|
|
for_each_node_mask(nid, node_states[N_MEMORY]) {
|
|
|
|
if (!test_mem_cgroup_node_reclaimable(memcg, nid, false))
|
|
node_clear(nid, memcg->scan_nodes);
|
|
}
|
|
|
|
atomic_set(&memcg->numainfo_events, 0);
|
|
atomic_set(&memcg->numainfo_updating, 0);
|
|
}
|
|
|
|
/*
|
|
* Selecting a node where we start reclaim from. Because what we need is just
|
|
* reducing usage counter, start from anywhere is O,K. Considering
|
|
* memory reclaim from current node, there are pros. and cons.
|
|
*
|
|
* Freeing memory from current node means freeing memory from a node which
|
|
* we'll use or we've used. So, it may make LRU bad. And if several threads
|
|
* hit limits, it will see a contention on a node. But freeing from remote
|
|
* node means more costs for memory reclaim because of memory latency.
|
|
*
|
|
* Now, we use round-robin. Better algorithm is welcomed.
|
|
*/
|
|
int mem_cgroup_select_victim_node(struct mem_cgroup *memcg)
|
|
{
|
|
int node;
|
|
|
|
mem_cgroup_may_update_nodemask(memcg);
|
|
node = memcg->last_scanned_node;
|
|
|
|
node = next_node(node, memcg->scan_nodes);
|
|
if (node == MAX_NUMNODES)
|
|
node = first_node(memcg->scan_nodes);
|
|
/*
|
|
* We call this when we hit limit, not when pages are added to LRU.
|
|
* No LRU may hold pages because all pages are UNEVICTABLE or
|
|
* memcg is too small and all pages are not on LRU. In that case,
|
|
* we use curret node.
|
|
*/
|
|
if (unlikely(node == MAX_NUMNODES))
|
|
node = numa_node_id();
|
|
|
|
memcg->last_scanned_node = node;
|
|
return node;
|
|
}
|
|
|
|
/*
|
|
* Check all nodes whether it contains reclaimable pages or not.
|
|
* For quick scan, we make use of scan_nodes. This will allow us to skip
|
|
* unused nodes. But scan_nodes is lazily updated and may not cotain
|
|
* enough new information. We need to do double check.
|
|
*/
|
|
static bool mem_cgroup_reclaimable(struct mem_cgroup *memcg, bool noswap)
|
|
{
|
|
int nid;
|
|
|
|
/*
|
|
* quick check...making use of scan_node.
|
|
* We can skip unused nodes.
|
|
*/
|
|
if (!nodes_empty(memcg->scan_nodes)) {
|
|
for (nid = first_node(memcg->scan_nodes);
|
|
nid < MAX_NUMNODES;
|
|
nid = next_node(nid, memcg->scan_nodes)) {
|
|
|
|
if (test_mem_cgroup_node_reclaimable(memcg, nid, noswap))
|
|
return true;
|
|
}
|
|
}
|
|
/*
|
|
* Check rest of nodes.
|
|
*/
|
|
for_each_node_state(nid, N_MEMORY) {
|
|
if (node_isset(nid, memcg->scan_nodes))
|
|
continue;
|
|
if (test_mem_cgroup_node_reclaimable(memcg, nid, noswap))
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
#else
|
|
int mem_cgroup_select_victim_node(struct mem_cgroup *memcg)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static bool mem_cgroup_reclaimable(struct mem_cgroup *memcg, bool noswap)
|
|
{
|
|
return test_mem_cgroup_node_reclaimable(memcg, 0, noswap);
|
|
}
|
|
#endif
|
|
|
|
static int mem_cgroup_soft_reclaim(struct mem_cgroup *root_memcg,
|
|
struct zone *zone,
|
|
gfp_t gfp_mask,
|
|
unsigned long *total_scanned)
|
|
{
|
|
struct mem_cgroup *victim = NULL;
|
|
int total = 0;
|
|
int loop = 0;
|
|
unsigned long excess;
|
|
unsigned long nr_scanned;
|
|
struct mem_cgroup_reclaim_cookie reclaim = {
|
|
.zone = zone,
|
|
.priority = 0,
|
|
};
|
|
|
|
excess = res_counter_soft_limit_excess(&root_memcg->res) >> PAGE_SHIFT;
|
|
|
|
while (1) {
|
|
victim = mem_cgroup_iter(root_memcg, victim, &reclaim);
|
|
if (!victim) {
|
|
loop++;
|
|
if (loop >= 2) {
|
|
/*
|
|
* If we have not been able to reclaim
|
|
* anything, it might because there are
|
|
* no reclaimable pages under this hierarchy
|
|
*/
|
|
if (!total)
|
|
break;
|
|
/*
|
|
* We want to do more targeted reclaim.
|
|
* excess >> 2 is not to excessive so as to
|
|
* reclaim too much, nor too less that we keep
|
|
* coming back to reclaim from this cgroup
|
|
*/
|
|
if (total >= (excess >> 2) ||
|
|
(loop > MEM_CGROUP_MAX_RECLAIM_LOOPS))
|
|
break;
|
|
}
|
|
continue;
|
|
}
|
|
if (!mem_cgroup_reclaimable(victim, false))
|
|
continue;
|
|
total += mem_cgroup_shrink_node_zone(victim, gfp_mask, false,
|
|
zone, &nr_scanned);
|
|
*total_scanned += nr_scanned;
|
|
if (!res_counter_soft_limit_excess(&root_memcg->res))
|
|
break;
|
|
}
|
|
mem_cgroup_iter_break(root_memcg, victim);
|
|
return total;
|
|
}
|
|
|
|
#ifdef CONFIG_LOCKDEP
|
|
static struct lockdep_map memcg_oom_lock_dep_map = {
|
|
.name = "memcg_oom_lock",
|
|
};
|
|
#endif
|
|
|
|
static DEFINE_SPINLOCK(memcg_oom_lock);
|
|
|
|
/*
|
|
* Check OOM-Killer is already running under our hierarchy.
|
|
* If someone is running, return false.
|
|
*/
|
|
static bool mem_cgroup_oom_trylock(struct mem_cgroup *memcg)
|
|
{
|
|
struct mem_cgroup *iter, *failed = NULL;
|
|
|
|
spin_lock(&memcg_oom_lock);
|
|
|
|
for_each_mem_cgroup_tree(iter, memcg) {
|
|
if (iter->oom_lock) {
|
|
/*
|
|
* this subtree of our hierarchy is already locked
|
|
* so we cannot give a lock.
|
|
*/
|
|
failed = iter;
|
|
mem_cgroup_iter_break(memcg, iter);
|
|
break;
|
|
} else
|
|
iter->oom_lock = true;
|
|
}
|
|
|
|
if (failed) {
|
|
/*
|
|
* OK, we failed to lock the whole subtree so we have
|
|
* to clean up what we set up to the failing subtree
|
|
*/
|
|
for_each_mem_cgroup_tree(iter, memcg) {
|
|
if (iter == failed) {
|
|
mem_cgroup_iter_break(memcg, iter);
|
|
break;
|
|
}
|
|
iter->oom_lock = false;
|
|
}
|
|
} else
|
|
mutex_acquire(&memcg_oom_lock_dep_map, 0, 1, _RET_IP_);
|
|
|
|
spin_unlock(&memcg_oom_lock);
|
|
|
|
return !failed;
|
|
}
|
|
|
|
static void mem_cgroup_oom_unlock(struct mem_cgroup *memcg)
|
|
{
|
|
struct mem_cgroup *iter;
|
|
|
|
spin_lock(&memcg_oom_lock);
|
|
mutex_release(&memcg_oom_lock_dep_map, 1, _RET_IP_);
|
|
for_each_mem_cgroup_tree(iter, memcg)
|
|
iter->oom_lock = false;
|
|
spin_unlock(&memcg_oom_lock);
|
|
}
|
|
|
|
static void mem_cgroup_mark_under_oom(struct mem_cgroup *memcg)
|
|
{
|
|
struct mem_cgroup *iter;
|
|
|
|
for_each_mem_cgroup_tree(iter, memcg)
|
|
atomic_inc(&iter->under_oom);
|
|
}
|
|
|
|
static void mem_cgroup_unmark_under_oom(struct mem_cgroup *memcg)
|
|
{
|
|
struct mem_cgroup *iter;
|
|
|
|
/*
|
|
* When a new child is created while the hierarchy is under oom,
|
|
* mem_cgroup_oom_lock() may not be called. We have to use
|
|
* atomic_add_unless() here.
|
|
*/
|
|
for_each_mem_cgroup_tree(iter, memcg)
|
|
atomic_add_unless(&iter->under_oom, -1, 0);
|
|
}
|
|
|
|
static DECLARE_WAIT_QUEUE_HEAD(memcg_oom_waitq);
|
|
|
|
struct oom_wait_info {
|
|
struct mem_cgroup *memcg;
|
|
wait_queue_t wait;
|
|
};
|
|
|
|
static int memcg_oom_wake_function(wait_queue_t *wait,
|
|
unsigned mode, int sync, void *arg)
|
|
{
|
|
struct mem_cgroup *wake_memcg = (struct mem_cgroup *)arg;
|
|
struct mem_cgroup *oom_wait_memcg;
|
|
struct oom_wait_info *oom_wait_info;
|
|
|
|
oom_wait_info = container_of(wait, struct oom_wait_info, wait);
|
|
oom_wait_memcg = oom_wait_info->memcg;
|
|
|
|
/*
|
|
* Both of oom_wait_info->memcg and wake_memcg are stable under us.
|
|
* Then we can use css_is_ancestor without taking care of RCU.
|
|
*/
|
|
if (!mem_cgroup_same_or_subtree(oom_wait_memcg, wake_memcg)
|
|
&& !mem_cgroup_same_or_subtree(wake_memcg, oom_wait_memcg))
|
|
return 0;
|
|
return autoremove_wake_function(wait, mode, sync, arg);
|
|
}
|
|
|
|
static void memcg_wakeup_oom(struct mem_cgroup *memcg)
|
|
{
|
|
atomic_inc(&memcg->oom_wakeups);
|
|
/* for filtering, pass "memcg" as argument. */
|
|
__wake_up(&memcg_oom_waitq, TASK_NORMAL, 0, memcg);
|
|
}
|
|
|
|
static void memcg_oom_recover(struct mem_cgroup *memcg)
|
|
{
|
|
if (memcg && atomic_read(&memcg->under_oom))
|
|
memcg_wakeup_oom(memcg);
|
|
}
|
|
|
|
static void mem_cgroup_oom(struct mem_cgroup *memcg, gfp_t mask, int order)
|
|
{
|
|
if (!current->memcg_oom.may_oom)
|
|
return;
|
|
/*
|
|
* We are in the middle of the charge context here, so we
|
|
* don't want to block when potentially sitting on a callstack
|
|
* that holds all kinds of filesystem and mm locks.
|
|
*
|
|
* Also, the caller may handle a failed allocation gracefully
|
|
* (like optional page cache readahead) and so an OOM killer
|
|
* invocation might not even be necessary.
|
|
*
|
|
* That's why we don't do anything here except remember the
|
|
* OOM context and then deal with it at the end of the page
|
|
* fault when the stack is unwound, the locks are released,
|
|
* and when we know whether the fault was overall successful.
|
|
*/
|
|
css_get(&memcg->css);
|
|
current->memcg_oom.memcg = memcg;
|
|
current->memcg_oom.gfp_mask = mask;
|
|
current->memcg_oom.order = order;
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_oom_synchronize - complete memcg OOM handling
|
|
* @handle: actually kill/wait or just clean up the OOM state
|
|
*
|
|
* This has to be called at the end of a page fault if the memcg OOM
|
|
* handler was enabled.
|
|
*
|
|
* Memcg supports userspace OOM handling where failed allocations must
|
|
* sleep on a waitqueue until the userspace task resolves the
|
|
* situation. Sleeping directly in the charge context with all kinds
|
|
* of locks held is not a good idea, instead we remember an OOM state
|
|
* in the task and mem_cgroup_oom_synchronize() has to be called at
|
|
* the end of the page fault to complete the OOM handling.
|
|
*
|
|
* Returns %true if an ongoing memcg OOM situation was detected and
|
|
* completed, %false otherwise.
|
|
*/
|
|
bool mem_cgroup_oom_synchronize(bool handle)
|
|
{
|
|
struct mem_cgroup *memcg = current->memcg_oom.memcg;
|
|
struct oom_wait_info owait;
|
|
bool locked;
|
|
|
|
/* OOM is global, do not handle */
|
|
if (!memcg)
|
|
return false;
|
|
|
|
if (!handle)
|
|
goto cleanup;
|
|
|
|
owait.memcg = memcg;
|
|
owait.wait.flags = 0;
|
|
owait.wait.func = memcg_oom_wake_function;
|
|
owait.wait.private = current;
|
|
INIT_LIST_HEAD(&owait.wait.task_list);
|
|
|
|
prepare_to_wait(&memcg_oom_waitq, &owait.wait, TASK_KILLABLE);
|
|
mem_cgroup_mark_under_oom(memcg);
|
|
|
|
locked = mem_cgroup_oom_trylock(memcg);
|
|
|
|
if (locked)
|
|
mem_cgroup_oom_notify(memcg);
|
|
|
|
if (locked && !memcg->oom_kill_disable) {
|
|
mem_cgroup_unmark_under_oom(memcg);
|
|
finish_wait(&memcg_oom_waitq, &owait.wait);
|
|
mem_cgroup_out_of_memory(memcg, current->memcg_oom.gfp_mask,
|
|
current->memcg_oom.order);
|
|
} else {
|
|
schedule();
|
|
mem_cgroup_unmark_under_oom(memcg);
|
|
finish_wait(&memcg_oom_waitq, &owait.wait);
|
|
}
|
|
|
|
if (locked) {
|
|
mem_cgroup_oom_unlock(memcg);
|
|
/*
|
|
* There is no guarantee that an OOM-lock contender
|
|
* sees the wakeups triggered by the OOM kill
|
|
* uncharges. Wake any sleepers explicitely.
|
|
*/
|
|
memcg_oom_recover(memcg);
|
|
}
|
|
cleanup:
|
|
current->memcg_oom.memcg = NULL;
|
|
css_put(&memcg->css);
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* Currently used to update mapped file statistics, but the routine can be
|
|
* generalized to update other statistics as well.
|
|
*
|
|
* Notes: Race condition
|
|
*
|
|
* We usually use page_cgroup_lock() for accessing page_cgroup member but
|
|
* it tends to be costly. But considering some conditions, we doesn't need
|
|
* to do so _always_.
|
|
*
|
|
* Considering "charge", lock_page_cgroup() is not required because all
|
|
* file-stat operations happen after a page is attached to radix-tree. There
|
|
* are no race with "charge".
|
|
*
|
|
* Considering "uncharge", we know that memcg doesn't clear pc->mem_cgroup
|
|
* at "uncharge" intentionally. So, we always see valid pc->mem_cgroup even
|
|
* if there are race with "uncharge". Statistics itself is properly handled
|
|
* by flags.
|
|
*
|
|
* Considering "move", this is an only case we see a race. To make the race
|
|
* small, we check mm->moving_account and detect there are possibility of race
|
|
* If there is, we take a lock.
|
|
*/
|
|
|
|
void __mem_cgroup_begin_update_page_stat(struct page *page,
|
|
bool *locked, unsigned long *flags)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
struct page_cgroup *pc;
|
|
|
|
pc = lookup_page_cgroup(page);
|
|
again:
|
|
memcg = pc->mem_cgroup;
|
|
if (unlikely(!memcg || !PageCgroupUsed(pc)))
|
|
return;
|
|
/*
|
|
* If this memory cgroup is not under account moving, we don't
|
|
* need to take move_lock_mem_cgroup(). Because we already hold
|
|
* rcu_read_lock(), any calls to move_account will be delayed until
|
|
* rcu_read_unlock() if mem_cgroup_stolen() == true.
|
|
*/
|
|
if (!mem_cgroup_stolen(memcg))
|
|
return;
|
|
|
|
move_lock_mem_cgroup(memcg, flags);
|
|
if (memcg != pc->mem_cgroup || !PageCgroupUsed(pc)) {
|
|
move_unlock_mem_cgroup(memcg, flags);
|
|
goto again;
|
|
}
|
|
*locked = true;
|
|
}
|
|
|
|
void __mem_cgroup_end_update_page_stat(struct page *page, unsigned long *flags)
|
|
{
|
|
struct page_cgroup *pc = lookup_page_cgroup(page);
|
|
|
|
/*
|
|
* It's guaranteed that pc->mem_cgroup never changes while
|
|
* lock is held because a routine modifies pc->mem_cgroup
|
|
* should take move_lock_mem_cgroup().
|
|
*/
|
|
move_unlock_mem_cgroup(pc->mem_cgroup, flags);
|
|
}
|
|
|
|
void mem_cgroup_update_page_stat(struct page *page,
|
|
enum mem_cgroup_stat_index idx, int val)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
struct page_cgroup *pc = lookup_page_cgroup(page);
|
|
unsigned long uninitialized_var(flags);
|
|
|
|
if (mem_cgroup_disabled())
|
|
return;
|
|
|
|
VM_BUG_ON(!rcu_read_lock_held());
|
|
memcg = pc->mem_cgroup;
|
|
if (unlikely(!memcg || !PageCgroupUsed(pc)))
|
|
return;
|
|
|
|
this_cpu_add(memcg->stat->count[idx], val);
|
|
}
|
|
|
|
/*
|
|
* size of first charge trial. "32" comes from vmscan.c's magic value.
|
|
* TODO: maybe necessary to use big numbers in big irons.
|
|
*/
|
|
#define CHARGE_BATCH 32U
|
|
struct memcg_stock_pcp {
|
|
struct mem_cgroup *cached; /* this never be root cgroup */
|
|
unsigned int nr_pages;
|
|
struct work_struct work;
|
|
unsigned long flags;
|
|
#define FLUSHING_CACHED_CHARGE 0
|
|
};
|
|
static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock);
|
|
static DEFINE_MUTEX(percpu_charge_mutex);
|
|
|
|
/**
|
|
* consume_stock: Try to consume stocked charge on this cpu.
|
|
* @memcg: memcg to consume from.
|
|
* @nr_pages: how many pages to charge.
|
|
*
|
|
* The charges will only happen if @memcg matches the current cpu's memcg
|
|
* stock, and at least @nr_pages are available in that stock. Failure to
|
|
* service an allocation will refill the stock.
|
|
*
|
|
* returns true if successful, false otherwise.
|
|
*/
|
|
static bool consume_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
|
|
{
|
|
struct memcg_stock_pcp *stock;
|
|
bool ret = true;
|
|
|
|
if (nr_pages > CHARGE_BATCH)
|
|
return false;
|
|
|
|
stock = &get_cpu_var(memcg_stock);
|
|
if (memcg == stock->cached && stock->nr_pages >= nr_pages)
|
|
stock->nr_pages -= nr_pages;
|
|
else /* need to call res_counter_charge */
|
|
ret = false;
|
|
put_cpu_var(memcg_stock);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Returns stocks cached in percpu to res_counter and reset cached information.
|
|
*/
|
|
static void drain_stock(struct memcg_stock_pcp *stock)
|
|
{
|
|
struct mem_cgroup *old = stock->cached;
|
|
|
|
if (stock->nr_pages) {
|
|
unsigned long bytes = stock->nr_pages * PAGE_SIZE;
|
|
|
|
res_counter_uncharge(&old->res, bytes);
|
|
if (do_swap_account)
|
|
res_counter_uncharge(&old->memsw, bytes);
|
|
stock->nr_pages = 0;
|
|
}
|
|
stock->cached = NULL;
|
|
}
|
|
|
|
/*
|
|
* This must be called under preempt disabled or must be called by
|
|
* a thread which is pinned to local cpu.
|
|
*/
|
|
static void drain_local_stock(struct work_struct *dummy)
|
|
{
|
|
struct memcg_stock_pcp *stock = &__get_cpu_var(memcg_stock);
|
|
drain_stock(stock);
|
|
clear_bit(FLUSHING_CACHED_CHARGE, &stock->flags);
|
|
}
|
|
|
|
static void __init memcg_stock_init(void)
|
|
{
|
|
int cpu;
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
struct memcg_stock_pcp *stock =
|
|
&per_cpu(memcg_stock, cpu);
|
|
INIT_WORK(&stock->work, drain_local_stock);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Cache charges(val) which is from res_counter, to local per_cpu area.
|
|
* This will be consumed by consume_stock() function, later.
|
|
*/
|
|
static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
|
|
{
|
|
struct memcg_stock_pcp *stock = &get_cpu_var(memcg_stock);
|
|
|
|
if (stock->cached != memcg) { /* reset if necessary */
|
|
drain_stock(stock);
|
|
stock->cached = memcg;
|
|
}
|
|
stock->nr_pages += nr_pages;
|
|
put_cpu_var(memcg_stock);
|
|
}
|
|
|
|
/*
|
|
* Drains all per-CPU charge caches for given root_memcg resp. subtree
|
|
* of the hierarchy under it. sync flag says whether we should block
|
|
* until the work is done.
|
|
*/
|
|
static void drain_all_stock(struct mem_cgroup *root_memcg, bool sync)
|
|
{
|
|
int cpu, curcpu;
|
|
|
|
/* Notify other cpus that system-wide "drain" is running */
|
|
get_online_cpus();
|
|
curcpu = get_cpu();
|
|
for_each_online_cpu(cpu) {
|
|
struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu);
|
|
struct mem_cgroup *memcg;
|
|
|
|
memcg = stock->cached;
|
|
if (!memcg || !stock->nr_pages)
|
|
continue;
|
|
if (!mem_cgroup_same_or_subtree(root_memcg, memcg))
|
|
continue;
|
|
if (!test_and_set_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) {
|
|
if (cpu == curcpu)
|
|
drain_local_stock(&stock->work);
|
|
else
|
|
schedule_work_on(cpu, &stock->work);
|
|
}
|
|
}
|
|
put_cpu();
|
|
|
|
if (!sync)
|
|
goto out;
|
|
|
|
for_each_online_cpu(cpu) {
|
|
struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu);
|
|
if (test_bit(FLUSHING_CACHED_CHARGE, &stock->flags))
|
|
flush_work(&stock->work);
|
|
}
|
|
out:
|
|
put_online_cpus();
|
|
}
|
|
|
|
/*
|
|
* Tries to drain stocked charges in other cpus. This function is asynchronous
|
|
* and just put a work per cpu for draining localy on each cpu. Caller can
|
|
* expects some charges will be back to res_counter later but cannot wait for
|
|
* it.
|
|
*/
|
|
static void drain_all_stock_async(struct mem_cgroup *root_memcg)
|
|
{
|
|
/*
|
|
* If someone calls draining, avoid adding more kworker runs.
|
|
*/
|
|
if (!mutex_trylock(&percpu_charge_mutex))
|
|
return;
|
|
drain_all_stock(root_memcg, false);
|
|
mutex_unlock(&percpu_charge_mutex);
|
|
}
|
|
|
|
/* This is a synchronous drain interface. */
|
|
static void drain_all_stock_sync(struct mem_cgroup *root_memcg)
|
|
{
|
|
/* called when force_empty is called */
|
|
mutex_lock(&percpu_charge_mutex);
|
|
drain_all_stock(root_memcg, true);
|
|
mutex_unlock(&percpu_charge_mutex);
|
|
}
|
|
|
|
/*
|
|
* This function drains percpu counter value from DEAD cpu and
|
|
* move it to local cpu. Note that this function can be preempted.
|
|
*/
|
|
static void mem_cgroup_drain_pcp_counter(struct mem_cgroup *memcg, int cpu)
|
|
{
|
|
int i;
|
|
|
|
spin_lock(&memcg->pcp_counter_lock);
|
|
for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) {
|
|
long x = per_cpu(memcg->stat->count[i], cpu);
|
|
|
|
per_cpu(memcg->stat->count[i], cpu) = 0;
|
|
memcg->nocpu_base.count[i] += x;
|
|
}
|
|
for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) {
|
|
unsigned long x = per_cpu(memcg->stat->events[i], cpu);
|
|
|
|
per_cpu(memcg->stat->events[i], cpu) = 0;
|
|
memcg->nocpu_base.events[i] += x;
|
|
}
|
|
spin_unlock(&memcg->pcp_counter_lock);
|
|
}
|
|
|
|
static int memcg_cpu_hotplug_callback(struct notifier_block *nb,
|
|
unsigned long action,
|
|
void *hcpu)
|
|
{
|
|
int cpu = (unsigned long)hcpu;
|
|
struct memcg_stock_pcp *stock;
|
|
struct mem_cgroup *iter;
|
|
|
|
if (action == CPU_ONLINE)
|
|
return NOTIFY_OK;
|
|
|
|
if (action != CPU_DEAD && action != CPU_DEAD_FROZEN)
|
|
return NOTIFY_OK;
|
|
|
|
for_each_mem_cgroup(iter)
|
|
mem_cgroup_drain_pcp_counter(iter, cpu);
|
|
|
|
stock = &per_cpu(memcg_stock, cpu);
|
|
drain_stock(stock);
|
|
return NOTIFY_OK;
|
|
}
|
|
|
|
|
|
/* See __mem_cgroup_try_charge() for details */
|
|
enum {
|
|
CHARGE_OK, /* success */
|
|
CHARGE_RETRY, /* need to retry but retry is not bad */
|
|
CHARGE_NOMEM, /* we can't do more. return -ENOMEM */
|
|
CHARGE_WOULDBLOCK, /* GFP_WAIT wasn't set and no enough res. */
|
|
};
|
|
|
|
static int mem_cgroup_do_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
|
|
unsigned int nr_pages, unsigned int min_pages,
|
|
bool invoke_oom)
|
|
{
|
|
unsigned long csize = nr_pages * PAGE_SIZE;
|
|
struct mem_cgroup *mem_over_limit;
|
|
struct res_counter *fail_res;
|
|
unsigned long flags = 0;
|
|
int ret;
|
|
|
|
ret = res_counter_charge(&memcg->res, csize, &fail_res);
|
|
|
|
if (likely(!ret)) {
|
|
if (!do_swap_account)
|
|
return CHARGE_OK;
|
|
ret = res_counter_charge(&memcg->memsw, csize, &fail_res);
|
|
if (likely(!ret))
|
|
return CHARGE_OK;
|
|
|
|
res_counter_uncharge(&memcg->res, csize);
|
|
mem_over_limit = mem_cgroup_from_res_counter(fail_res, memsw);
|
|
flags |= MEM_CGROUP_RECLAIM_NOSWAP;
|
|
} else
|
|
mem_over_limit = mem_cgroup_from_res_counter(fail_res, res);
|
|
/*
|
|
* Never reclaim on behalf of optional batching, retry with a
|
|
* single page instead.
|
|
*/
|
|
if (nr_pages > min_pages)
|
|
return CHARGE_RETRY;
|
|
|
|
if (!(gfp_mask & __GFP_WAIT))
|
|
return CHARGE_WOULDBLOCK;
|
|
|
|
if (gfp_mask & __GFP_NORETRY)
|
|
return CHARGE_NOMEM;
|
|
|
|
ret = mem_cgroup_reclaim(mem_over_limit, gfp_mask, flags);
|
|
if (mem_cgroup_margin(mem_over_limit) >= nr_pages)
|
|
return CHARGE_RETRY;
|
|
/*
|
|
* Even though the limit is exceeded at this point, reclaim
|
|
* may have been able to free some pages. Retry the charge
|
|
* before killing the task.
|
|
*
|
|
* Only for regular pages, though: huge pages are rather
|
|
* unlikely to succeed so close to the limit, and we fall back
|
|
* to regular pages anyway in case of failure.
|
|
*/
|
|
if (nr_pages <= (1 << PAGE_ALLOC_COSTLY_ORDER) && ret)
|
|
return CHARGE_RETRY;
|
|
|
|
/*
|
|
* At task move, charge accounts can be doubly counted. So, it's
|
|
* better to wait until the end of task_move if something is going on.
|
|
*/
|
|
if (mem_cgroup_wait_acct_move(mem_over_limit))
|
|
return CHARGE_RETRY;
|
|
|
|
if (invoke_oom)
|
|
mem_cgroup_oom(mem_over_limit, gfp_mask, get_order(csize));
|
|
|
|
return CHARGE_NOMEM;
|
|
}
|
|
|
|
/*
|
|
* __mem_cgroup_try_charge() does
|
|
* 1. detect memcg to be charged against from passed *mm and *ptr,
|
|
* 2. update res_counter
|
|
* 3. call memory reclaim if necessary.
|
|
*
|
|
* In some special case, if the task is fatal, fatal_signal_pending() or
|
|
* has TIF_MEMDIE, this function returns -EINTR while writing root_mem_cgroup
|
|
* to *ptr. There are two reasons for this. 1: fatal threads should quit as soon
|
|
* as possible without any hazards. 2: all pages should have a valid
|
|
* pc->mem_cgroup. If mm is NULL and the caller doesn't pass a valid memcg
|
|
* pointer, that is treated as a charge to root_mem_cgroup.
|
|
*
|
|
* So __mem_cgroup_try_charge() will return
|
|
* 0 ... on success, filling *ptr with a valid memcg pointer.
|
|
* -ENOMEM ... charge failure because of resource limits.
|
|
* -EINTR ... if thread is fatal. *ptr is filled with root_mem_cgroup.
|
|
*
|
|
* Unlike the exported interface, an "oom" parameter is added. if oom==true,
|
|
* the oom-killer can be invoked.
|
|
*/
|
|
static int __mem_cgroup_try_charge(struct mm_struct *mm,
|
|
gfp_t gfp_mask,
|
|
unsigned int nr_pages,
|
|
struct mem_cgroup **ptr,
|
|
bool oom)
|
|
{
|
|
unsigned int batch = max(CHARGE_BATCH, nr_pages);
|
|
int nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES;
|
|
struct mem_cgroup *memcg = NULL;
|
|
int ret;
|
|
|
|
/*
|
|
* Unlike gloval-vm's OOM-kill, we're not in memory shortage
|
|
* in system level. So, allow to go ahead dying process in addition to
|
|
* MEMDIE process.
|
|
*/
|
|
if (unlikely(test_thread_flag(TIF_MEMDIE)
|
|
|| fatal_signal_pending(current)))
|
|
goto bypass;
|
|
|
|
if (unlikely(task_in_memcg_oom(current)))
|
|
goto bypass;
|
|
|
|
/*
|
|
* We always charge the cgroup the mm_struct belongs to.
|
|
* The mm_struct's mem_cgroup changes on task migration if the
|
|
* thread group leader migrates. It's possible that mm is not
|
|
* set, if so charge the root memcg (happens for pagecache usage).
|
|
*/
|
|
if (!*ptr && !mm)
|
|
*ptr = root_mem_cgroup;
|
|
again:
|
|
if (*ptr) { /* css should be a valid one */
|
|
memcg = *ptr;
|
|
if (mem_cgroup_is_root(memcg))
|
|
goto done;
|
|
if (consume_stock(memcg, nr_pages))
|
|
goto done;
|
|
css_get(&memcg->css);
|
|
} else {
|
|
struct task_struct *p;
|
|
|
|
rcu_read_lock();
|
|
p = rcu_dereference(mm->owner);
|
|
/*
|
|
* Because we don't have task_lock(), "p" can exit.
|
|
* In that case, "memcg" can point to root or p can be NULL with
|
|
* race with swapoff. Then, we have small risk of mis-accouning.
|
|
* But such kind of mis-account by race always happens because
|
|
* we don't have cgroup_mutex(). It's overkill and we allo that
|
|
* small race, here.
|
|
* (*) swapoff at el will charge against mm-struct not against
|
|
* task-struct. So, mm->owner can be NULL.
|
|
*/
|
|
memcg = mem_cgroup_from_task(p);
|
|
if (!memcg)
|
|
memcg = root_mem_cgroup;
|
|
if (mem_cgroup_is_root(memcg)) {
|
|
rcu_read_unlock();
|
|
goto done;
|
|
}
|
|
if (consume_stock(memcg, nr_pages)) {
|
|
/*
|
|
* It seems dagerous to access memcg without css_get().
|
|
* But considering how consume_stok works, it's not
|
|
* necessary. If consume_stock success, some charges
|
|
* from this memcg are cached on this cpu. So, we
|
|
* don't need to call css_get()/css_tryget() before
|
|
* calling consume_stock().
|
|
*/
|
|
rcu_read_unlock();
|
|
goto done;
|
|
}
|
|
/* after here, we may be blocked. we need to get refcnt */
|
|
if (!css_tryget(&memcg->css)) {
|
|
rcu_read_unlock();
|
|
goto again;
|
|
}
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
do {
|
|
bool invoke_oom = oom && !nr_oom_retries;
|
|
|
|
/* If killed, bypass charge */
|
|
if (fatal_signal_pending(current)) {
|
|
css_put(&memcg->css);
|
|
goto bypass;
|
|
}
|
|
|
|
ret = mem_cgroup_do_charge(memcg, gfp_mask, batch,
|
|
nr_pages, invoke_oom);
|
|
switch (ret) {
|
|
case CHARGE_OK:
|
|
break;
|
|
case CHARGE_RETRY: /* not in OOM situation but retry */
|
|
batch = nr_pages;
|
|
css_put(&memcg->css);
|
|
memcg = NULL;
|
|
goto again;
|
|
case CHARGE_WOULDBLOCK: /* !__GFP_WAIT */
|
|
css_put(&memcg->css);
|
|
goto nomem;
|
|
case CHARGE_NOMEM: /* OOM routine works */
|
|
if (!oom || invoke_oom) {
|
|
css_put(&memcg->css);
|
|
goto nomem;
|
|
}
|
|
nr_oom_retries--;
|
|
break;
|
|
}
|
|
} while (ret != CHARGE_OK);
|
|
|
|
if (batch > nr_pages)
|
|
refill_stock(memcg, batch - nr_pages);
|
|
css_put(&memcg->css);
|
|
done:
|
|
*ptr = memcg;
|
|
return 0;
|
|
nomem:
|
|
if (!(gfp_mask & __GFP_NOFAIL)) {
|
|
*ptr = NULL;
|
|
return -ENOMEM;
|
|
}
|
|
bypass:
|
|
*ptr = root_mem_cgroup;
|
|
return -EINTR;
|
|
}
|
|
|
|
/*
|
|
* Somemtimes we have to undo a charge we got by try_charge().
|
|
* This function is for that and do uncharge, put css's refcnt.
|
|
* gotten by try_charge().
|
|
*/
|
|
static void __mem_cgroup_cancel_charge(struct mem_cgroup *memcg,
|
|
unsigned int nr_pages)
|
|
{
|
|
if (!mem_cgroup_is_root(memcg)) {
|
|
unsigned long bytes = nr_pages * PAGE_SIZE;
|
|
|
|
res_counter_uncharge(&memcg->res, bytes);
|
|
if (do_swap_account)
|
|
res_counter_uncharge(&memcg->memsw, bytes);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Cancel chrages in this cgroup....doesn't propagate to parent cgroup.
|
|
* This is useful when moving usage to parent cgroup.
|
|
*/
|
|
static void __mem_cgroup_cancel_local_charge(struct mem_cgroup *memcg,
|
|
unsigned int nr_pages)
|
|
{
|
|
unsigned long bytes = nr_pages * PAGE_SIZE;
|
|
|
|
if (mem_cgroup_is_root(memcg))
|
|
return;
|
|
|
|
res_counter_uncharge_until(&memcg->res, memcg->res.parent, bytes);
|
|
if (do_swap_account)
|
|
res_counter_uncharge_until(&memcg->memsw,
|
|
memcg->memsw.parent, bytes);
|
|
}
|
|
|
|
/*
|
|
* A helper function to get mem_cgroup from ID. must be called under
|
|
* rcu_read_lock(). The caller is responsible for calling css_tryget if
|
|
* the mem_cgroup is used for charging. (dropping refcnt from swap can be
|
|
* called against removed memcg.)
|
|
*/
|
|
static struct mem_cgroup *mem_cgroup_lookup(unsigned short id)
|
|
{
|
|
struct cgroup_subsys_state *css;
|
|
|
|
/* ID 0 is unused ID */
|
|
if (!id)
|
|
return NULL;
|
|
css = css_lookup(&mem_cgroup_subsys, id);
|
|
if (!css)
|
|
return NULL;
|
|
return mem_cgroup_from_css(css);
|
|
}
|
|
|
|
struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page)
|
|
{
|
|
struct mem_cgroup *memcg = NULL;
|
|
struct page_cgroup *pc;
|
|
unsigned short id;
|
|
swp_entry_t ent;
|
|
|
|
VM_BUG_ON(!PageLocked(page));
|
|
|
|
pc = lookup_page_cgroup(page);
|
|
lock_page_cgroup(pc);
|
|
if (PageCgroupUsed(pc)) {
|
|
memcg = pc->mem_cgroup;
|
|
if (memcg && !css_tryget(&memcg->css))
|
|
memcg = NULL;
|
|
} else if (PageSwapCache(page)) {
|
|
ent.val = page_private(page);
|
|
id = lookup_swap_cgroup_id(ent);
|
|
rcu_read_lock();
|
|
memcg = mem_cgroup_lookup(id);
|
|
if (memcg && !css_tryget(&memcg->css))
|
|
memcg = NULL;
|
|
rcu_read_unlock();
|
|
}
|
|
unlock_page_cgroup(pc);
|
|
return memcg;
|
|
}
|
|
|
|
static void __mem_cgroup_commit_charge(struct mem_cgroup *memcg,
|
|
struct page *page,
|
|
unsigned int nr_pages,
|
|
enum charge_type ctype,
|
|
bool lrucare)
|
|
{
|
|
struct page_cgroup *pc = lookup_page_cgroup(page);
|
|
struct zone *uninitialized_var(zone);
|
|
struct lruvec *lruvec;
|
|
bool was_on_lru = false;
|
|
bool anon;
|
|
|
|
lock_page_cgroup(pc);
|
|
VM_BUG_ON(PageCgroupUsed(pc));
|
|
/*
|
|
* we don't need page_cgroup_lock about tail pages, becase they are not
|
|
* accessed by any other context at this point.
|
|
*/
|
|
|
|
/*
|
|
* In some cases, SwapCache and FUSE(splice_buf->radixtree), the page
|
|
* may already be on some other mem_cgroup's LRU. Take care of it.
|
|
*/
|
|
if (lrucare) {
|
|
zone = page_zone(page);
|
|
spin_lock_irq(&zone->lru_lock);
|
|
if (PageLRU(page)) {
|
|
lruvec = mem_cgroup_zone_lruvec(zone, pc->mem_cgroup);
|
|
ClearPageLRU(page);
|
|
del_page_from_lru_list(page, lruvec, page_lru(page));
|
|
was_on_lru = true;
|
|
}
|
|
}
|
|
|
|
pc->mem_cgroup = memcg;
|
|
/*
|
|
* We access a page_cgroup asynchronously without lock_page_cgroup().
|
|
* Especially when a page_cgroup is taken from a page, pc->mem_cgroup
|
|
* is accessed after testing USED bit. To make pc->mem_cgroup visible
|
|
* before USED bit, we need memory barrier here.
|
|
* See mem_cgroup_add_lru_list(), etc.
|
|
*/
|
|
smp_wmb();
|
|
SetPageCgroupUsed(pc);
|
|
|
|
if (lrucare) {
|
|
if (was_on_lru) {
|
|
lruvec = mem_cgroup_zone_lruvec(zone, pc->mem_cgroup);
|
|
VM_BUG_ON(PageLRU(page));
|
|
SetPageLRU(page);
|
|
add_page_to_lru_list(page, lruvec, page_lru(page));
|
|
}
|
|
spin_unlock_irq(&zone->lru_lock);
|
|
}
|
|
|
|
if (ctype == MEM_CGROUP_CHARGE_TYPE_ANON)
|
|
anon = true;
|
|
else
|
|
anon = false;
|
|
|
|
mem_cgroup_charge_statistics(memcg, page, anon, nr_pages);
|
|
unlock_page_cgroup(pc);
|
|
|
|
/*
|
|
* "charge_statistics" updated event counter. Then, check it.
|
|
* Insert ancestor (and ancestor's ancestors), to softlimit RB-tree.
|
|
* if they exceeds softlimit.
|
|
*/
|
|
memcg_check_events(memcg, page);
|
|
}
|
|
|
|
static DEFINE_MUTEX(set_limit_mutex);
|
|
|
|
#ifdef CONFIG_MEMCG_KMEM
|
|
static inline bool memcg_can_account_kmem(struct mem_cgroup *memcg)
|
|
{
|
|
return !mem_cgroup_disabled() && !mem_cgroup_is_root(memcg) &&
|
|
(memcg->kmem_account_flags & KMEM_ACCOUNTED_MASK);
|
|
}
|
|
|
|
/*
|
|
* This is a bit cumbersome, but it is rarely used and avoids a backpointer
|
|
* in the memcg_cache_params struct.
|
|
*/
|
|
static struct kmem_cache *memcg_params_to_cache(struct memcg_cache_params *p)
|
|
{
|
|
struct kmem_cache *cachep;
|
|
|
|
VM_BUG_ON(p->is_root_cache);
|
|
cachep = p->root_cache;
|
|
return cachep->memcg_params->memcg_caches[memcg_cache_id(p->memcg)];
|
|
}
|
|
|
|
#ifdef CONFIG_SLABINFO
|
|
static int mem_cgroup_slabinfo_read(struct cgroup_subsys_state *css,
|
|
struct cftype *cft, struct seq_file *m)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
struct memcg_cache_params *params;
|
|
|
|
if (!memcg_can_account_kmem(memcg))
|
|
return -EIO;
|
|
|
|
print_slabinfo_header(m);
|
|
|
|
mutex_lock(&memcg->slab_caches_mutex);
|
|
list_for_each_entry(params, &memcg->memcg_slab_caches, list)
|
|
cache_show(memcg_params_to_cache(params), m);
|
|
mutex_unlock(&memcg->slab_caches_mutex);
|
|
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
static int memcg_charge_kmem(struct mem_cgroup *memcg, gfp_t gfp, u64 size)
|
|
{
|
|
struct res_counter *fail_res;
|
|
struct mem_cgroup *_memcg;
|
|
int ret = 0;
|
|
bool may_oom;
|
|
|
|
ret = res_counter_charge(&memcg->kmem, size, &fail_res);
|
|
if (ret)
|
|
return ret;
|
|
|
|
/*
|
|
* Conditions under which we can wait for the oom_killer. Those are
|
|
* the same conditions tested by the core page allocator
|
|
*/
|
|
may_oom = (gfp & __GFP_FS) && !(gfp & __GFP_NORETRY);
|
|
|
|
_memcg = memcg;
|
|
ret = __mem_cgroup_try_charge(NULL, gfp, size >> PAGE_SHIFT,
|
|
&_memcg, may_oom);
|
|
|
|
if (ret == -EINTR) {
|
|
/*
|
|
* __mem_cgroup_try_charge() chosed to bypass to root due to
|
|
* OOM kill or fatal signal. Since our only options are to
|
|
* either fail the allocation or charge it to this cgroup, do
|
|
* it as a temporary condition. But we can't fail. From a
|
|
* kmem/slab perspective, the cache has already been selected,
|
|
* by mem_cgroup_kmem_get_cache(), so it is too late to change
|
|
* our minds.
|
|
*
|
|
* This condition will only trigger if the task entered
|
|
* memcg_charge_kmem in a sane state, but was OOM-killed during
|
|
* __mem_cgroup_try_charge() above. Tasks that were already
|
|
* dying when the allocation triggers should have been already
|
|
* directed to the root cgroup in memcontrol.h
|
|
*/
|
|
res_counter_charge_nofail(&memcg->res, size, &fail_res);
|
|
if (do_swap_account)
|
|
res_counter_charge_nofail(&memcg->memsw, size,
|
|
&fail_res);
|
|
ret = 0;
|
|
} else if (ret)
|
|
res_counter_uncharge(&memcg->kmem, size);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void memcg_uncharge_kmem(struct mem_cgroup *memcg, u64 size)
|
|
{
|
|
res_counter_uncharge(&memcg->res, size);
|
|
if (do_swap_account)
|
|
res_counter_uncharge(&memcg->memsw, size);
|
|
|
|
/* Not down to 0 */
|
|
if (res_counter_uncharge(&memcg->kmem, size))
|
|
return;
|
|
|
|
/*
|
|
* Releases a reference taken in kmem_cgroup_css_offline in case
|
|
* this last uncharge is racing with the offlining code or it is
|
|
* outliving the memcg existence.
|
|
*
|
|
* The memory barrier imposed by test&clear is paired with the
|
|
* explicit one in memcg_kmem_mark_dead().
|
|
*/
|
|
if (memcg_kmem_test_and_clear_dead(memcg))
|
|
css_put(&memcg->css);
|
|
}
|
|
|
|
void memcg_cache_list_add(struct mem_cgroup *memcg, struct kmem_cache *cachep)
|
|
{
|
|
if (!memcg)
|
|
return;
|
|
|
|
mutex_lock(&memcg->slab_caches_mutex);
|
|
list_add(&cachep->memcg_params->list, &memcg->memcg_slab_caches);
|
|
mutex_unlock(&memcg->slab_caches_mutex);
|
|
}
|
|
|
|
/*
|
|
* helper for acessing a memcg's index. It will be used as an index in the
|
|
* child cache array in kmem_cache, and also to derive its name. This function
|
|
* will return -1 when this is not a kmem-limited memcg.
|
|
*/
|
|
int memcg_cache_id(struct mem_cgroup *memcg)
|
|
{
|
|
return memcg ? memcg->kmemcg_id : -1;
|
|
}
|
|
|
|
/*
|
|
* This ends up being protected by the set_limit mutex, during normal
|
|
* operation, because that is its main call site.
|
|
*
|
|
* But when we create a new cache, we can call this as well if its parent
|
|
* is kmem-limited. That will have to hold set_limit_mutex as well.
|
|
*/
|
|
int memcg_update_cache_sizes(struct mem_cgroup *memcg)
|
|
{
|
|
int num, ret;
|
|
|
|
num = ida_simple_get(&kmem_limited_groups,
|
|
0, MEMCG_CACHES_MAX_SIZE, GFP_KERNEL);
|
|
if (num < 0)
|
|
return num;
|
|
/*
|
|
* After this point, kmem_accounted (that we test atomically in
|
|
* the beginning of this conditional), is no longer 0. This
|
|
* guarantees only one process will set the following boolean
|
|
* to true. We don't need test_and_set because we're protected
|
|
* by the set_limit_mutex anyway.
|
|
*/
|
|
memcg_kmem_set_activated(memcg);
|
|
|
|
ret = memcg_update_all_caches(num+1);
|
|
if (ret) {
|
|
ida_simple_remove(&kmem_limited_groups, num);
|
|
memcg_kmem_clear_activated(memcg);
|
|
return ret;
|
|
}
|
|
|
|
memcg->kmemcg_id = num;
|
|
INIT_LIST_HEAD(&memcg->memcg_slab_caches);
|
|
mutex_init(&memcg->slab_caches_mutex);
|
|
return 0;
|
|
}
|
|
|
|
static size_t memcg_caches_array_size(int num_groups)
|
|
{
|
|
ssize_t size;
|
|
if (num_groups <= 0)
|
|
return 0;
|
|
|
|
size = 2 * num_groups;
|
|
if (size < MEMCG_CACHES_MIN_SIZE)
|
|
size = MEMCG_CACHES_MIN_SIZE;
|
|
else if (size > MEMCG_CACHES_MAX_SIZE)
|
|
size = MEMCG_CACHES_MAX_SIZE;
|
|
|
|
return size;
|
|
}
|
|
|
|
/*
|
|
* We should update the current array size iff all caches updates succeed. This
|
|
* can only be done from the slab side. The slab mutex needs to be held when
|
|
* calling this.
|
|
*/
|
|
void memcg_update_array_size(int num)
|
|
{
|
|
if (num > memcg_limited_groups_array_size)
|
|
memcg_limited_groups_array_size = memcg_caches_array_size(num);
|
|
}
|
|
|
|
static void kmem_cache_destroy_work_func(struct work_struct *w);
|
|
|
|
int memcg_update_cache_size(struct kmem_cache *s, int num_groups)
|
|
{
|
|
struct memcg_cache_params *cur_params = s->memcg_params;
|
|
|
|
VM_BUG_ON(s->memcg_params && !s->memcg_params->is_root_cache);
|
|
|
|
if (num_groups > memcg_limited_groups_array_size) {
|
|
int i;
|
|
ssize_t size = memcg_caches_array_size(num_groups);
|
|
|
|
size *= sizeof(void *);
|
|
size += offsetof(struct memcg_cache_params, memcg_caches);
|
|
|
|
s->memcg_params = kzalloc(size, GFP_KERNEL);
|
|
if (!s->memcg_params) {
|
|
s->memcg_params = cur_params;
|
|
return -ENOMEM;
|
|
}
|
|
|
|
s->memcg_params->is_root_cache = true;
|
|
|
|
/*
|
|
* There is the chance it will be bigger than
|
|
* memcg_limited_groups_array_size, if we failed an allocation
|
|
* in a cache, in which case all caches updated before it, will
|
|
* have a bigger array.
|
|
*
|
|
* But if that is the case, the data after
|
|
* memcg_limited_groups_array_size is certainly unused
|
|
*/
|
|
for (i = 0; i < memcg_limited_groups_array_size; i++) {
|
|
if (!cur_params->memcg_caches[i])
|
|
continue;
|
|
s->memcg_params->memcg_caches[i] =
|
|
cur_params->memcg_caches[i];
|
|
}
|
|
|
|
/*
|
|
* Ideally, we would wait until all caches succeed, and only
|
|
* then free the old one. But this is not worth the extra
|
|
* pointer per-cache we'd have to have for this.
|
|
*
|
|
* It is not a big deal if some caches are left with a size
|
|
* bigger than the others. And all updates will reset this
|
|
* anyway.
|
|
*/
|
|
kfree(cur_params);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int memcg_register_cache(struct mem_cgroup *memcg, struct kmem_cache *s,
|
|
struct kmem_cache *root_cache)
|
|
{
|
|
size_t size;
|
|
|
|
if (!memcg_kmem_enabled())
|
|
return 0;
|
|
|
|
if (!memcg) {
|
|
size = offsetof(struct memcg_cache_params, memcg_caches);
|
|
size += memcg_limited_groups_array_size * sizeof(void *);
|
|
} else
|
|
size = sizeof(struct memcg_cache_params);
|
|
|
|
s->memcg_params = kzalloc(size, GFP_KERNEL);
|
|
if (!s->memcg_params)
|
|
return -ENOMEM;
|
|
|
|
if (memcg) {
|
|
s->memcg_params->memcg = memcg;
|
|
s->memcg_params->root_cache = root_cache;
|
|
INIT_WORK(&s->memcg_params->destroy,
|
|
kmem_cache_destroy_work_func);
|
|
} else
|
|
s->memcg_params->is_root_cache = true;
|
|
|
|
return 0;
|
|
}
|
|
|
|
void memcg_release_cache(struct kmem_cache *s)
|
|
{
|
|
struct kmem_cache *root;
|
|
struct mem_cgroup *memcg;
|
|
int id;
|
|
|
|
/*
|
|
* This happens, for instance, when a root cache goes away before we
|
|
* add any memcg.
|
|
*/
|
|
if (!s->memcg_params)
|
|
return;
|
|
|
|
if (s->memcg_params->is_root_cache)
|
|
goto out;
|
|
|
|
memcg = s->memcg_params->memcg;
|
|
id = memcg_cache_id(memcg);
|
|
|
|
root = s->memcg_params->root_cache;
|
|
root->memcg_params->memcg_caches[id] = NULL;
|
|
|
|
mutex_lock(&memcg->slab_caches_mutex);
|
|
list_del(&s->memcg_params->list);
|
|
mutex_unlock(&memcg->slab_caches_mutex);
|
|
|
|
css_put(&memcg->css);
|
|
out:
|
|
kfree(s->memcg_params);
|
|
}
|
|
|
|
/*
|
|
* During the creation a new cache, we need to disable our accounting mechanism
|
|
* altogether. This is true even if we are not creating, but rather just
|
|
* enqueing new caches to be created.
|
|
*
|
|
* This is because that process will trigger allocations; some visible, like
|
|
* explicit kmallocs to auxiliary data structures, name strings and internal
|
|
* cache structures; some well concealed, like INIT_WORK() that can allocate
|
|
* objects during debug.
|
|
*
|
|
* If any allocation happens during memcg_kmem_get_cache, we will recurse back
|
|
* to it. This may not be a bounded recursion: since the first cache creation
|
|
* failed to complete (waiting on the allocation), we'll just try to create the
|
|
* cache again, failing at the same point.
|
|
*
|
|
* memcg_kmem_get_cache is prepared to abort after seeing a positive count of
|
|
* memcg_kmem_skip_account. So we enclose anything that might allocate memory
|
|
* inside the following two functions.
|
|
*/
|
|
static inline void memcg_stop_kmem_account(void)
|
|
{
|
|
VM_BUG_ON(!current->mm);
|
|
current->memcg_kmem_skip_account++;
|
|
}
|
|
|
|
static inline void memcg_resume_kmem_account(void)
|
|
{
|
|
VM_BUG_ON(!current->mm);
|
|
current->memcg_kmem_skip_account--;
|
|
}
|
|
|
|
static void kmem_cache_destroy_work_func(struct work_struct *w)
|
|
{
|
|
struct kmem_cache *cachep;
|
|
struct memcg_cache_params *p;
|
|
|
|
p = container_of(w, struct memcg_cache_params, destroy);
|
|
|
|
cachep = memcg_params_to_cache(p);
|
|
|
|
/*
|
|
* If we get down to 0 after shrink, we could delete right away.
|
|
* However, memcg_release_pages() already puts us back in the workqueue
|
|
* in that case. If we proceed deleting, we'll get a dangling
|
|
* reference, and removing the object from the workqueue in that case
|
|
* is unnecessary complication. We are not a fast path.
|
|
*
|
|
* Note that this case is fundamentally different from racing with
|
|
* shrink_slab(): if memcg_cgroup_destroy_cache() is called in
|
|
* kmem_cache_shrink, not only we would be reinserting a dead cache
|
|
* into the queue, but doing so from inside the worker racing to
|
|
* destroy it.
|
|
*
|
|
* So if we aren't down to zero, we'll just schedule a worker and try
|
|
* again
|
|
*/
|
|
if (atomic_read(&cachep->memcg_params->nr_pages) != 0) {
|
|
kmem_cache_shrink(cachep);
|
|
if (atomic_read(&cachep->memcg_params->nr_pages) == 0)
|
|
return;
|
|
} else
|
|
kmem_cache_destroy(cachep);
|
|
}
|
|
|
|
void mem_cgroup_destroy_cache(struct kmem_cache *cachep)
|
|
{
|
|
if (!cachep->memcg_params->dead)
|
|
return;
|
|
|
|
/*
|
|
* There are many ways in which we can get here.
|
|
*
|
|
* We can get to a memory-pressure situation while the delayed work is
|
|
* still pending to run. The vmscan shrinkers can then release all
|
|
* cache memory and get us to destruction. If this is the case, we'll
|
|
* be executed twice, which is a bug (the second time will execute over
|
|
* bogus data). In this case, cancelling the work should be fine.
|
|
*
|
|
* But we can also get here from the worker itself, if
|
|
* kmem_cache_shrink is enough to shake all the remaining objects and
|
|
* get the page count to 0. In this case, we'll deadlock if we try to
|
|
* cancel the work (the worker runs with an internal lock held, which
|
|
* is the same lock we would hold for cancel_work_sync().)
|
|
*
|
|
* Since we can't possibly know who got us here, just refrain from
|
|
* running if there is already work pending
|
|
*/
|
|
if (work_pending(&cachep->memcg_params->destroy))
|
|
return;
|
|
/*
|
|
* We have to defer the actual destroying to a workqueue, because
|
|
* we might currently be in a context that cannot sleep.
|
|
*/
|
|
schedule_work(&cachep->memcg_params->destroy);
|
|
}
|
|
|
|
/*
|
|
* This lock protects updaters, not readers. We want readers to be as fast as
|
|
* they can, and they will either see NULL or a valid cache value. Our model
|
|
* allow them to see NULL, in which case the root memcg will be selected.
|
|
*
|
|
* We need this lock because multiple allocations to the same cache from a non
|
|
* will span more than one worker. Only one of them can create the cache.
|
|
*/
|
|
static DEFINE_MUTEX(memcg_cache_mutex);
|
|
|
|
/*
|
|
* Called with memcg_cache_mutex held
|
|
*/
|
|
static struct kmem_cache *kmem_cache_dup(struct mem_cgroup *memcg,
|
|
struct kmem_cache *s)
|
|
{
|
|
struct kmem_cache *new;
|
|
static char *tmp_name = NULL;
|
|
|
|
lockdep_assert_held(&memcg_cache_mutex);
|
|
|
|
/*
|
|
* kmem_cache_create_memcg duplicates the given name and
|
|
* cgroup_name for this name requires RCU context.
|
|
* This static temporary buffer is used to prevent from
|
|
* pointless shortliving allocation.
|
|
*/
|
|
if (!tmp_name) {
|
|
tmp_name = kmalloc(PATH_MAX, GFP_KERNEL);
|
|
if (!tmp_name)
|
|
return NULL;
|
|
}
|
|
|
|
rcu_read_lock();
|
|
snprintf(tmp_name, PATH_MAX, "%s(%d:%s)", s->name,
|
|
memcg_cache_id(memcg), cgroup_name(memcg->css.cgroup));
|
|
rcu_read_unlock();
|
|
|
|
new = kmem_cache_create_memcg(memcg, tmp_name, s->object_size, s->align,
|
|
(s->flags & ~SLAB_PANIC), s->ctor, s);
|
|
|
|
if (new)
|
|
new->allocflags |= __GFP_KMEMCG;
|
|
|
|
return new;
|
|
}
|
|
|
|
static struct kmem_cache *memcg_create_kmem_cache(struct mem_cgroup *memcg,
|
|
struct kmem_cache *cachep)
|
|
{
|
|
struct kmem_cache *new_cachep;
|
|
int idx;
|
|
|
|
BUG_ON(!memcg_can_account_kmem(memcg));
|
|
|
|
idx = memcg_cache_id(memcg);
|
|
|
|
mutex_lock(&memcg_cache_mutex);
|
|
new_cachep = cachep->memcg_params->memcg_caches[idx];
|
|
if (new_cachep) {
|
|
css_put(&memcg->css);
|
|
goto out;
|
|
}
|
|
|
|
new_cachep = kmem_cache_dup(memcg, cachep);
|
|
if (new_cachep == NULL) {
|
|
new_cachep = cachep;
|
|
css_put(&memcg->css);
|
|
goto out;
|
|
}
|
|
|
|
atomic_set(&new_cachep->memcg_params->nr_pages , 0);
|
|
|
|
cachep->memcg_params->memcg_caches[idx] = new_cachep;
|
|
/*
|
|
* the readers won't lock, make sure everybody sees the updated value,
|
|
* so they won't put stuff in the queue again for no reason
|
|
*/
|
|
wmb();
|
|
out:
|
|
mutex_unlock(&memcg_cache_mutex);
|
|
return new_cachep;
|
|
}
|
|
|
|
void kmem_cache_destroy_memcg_children(struct kmem_cache *s)
|
|
{
|
|
struct kmem_cache *c;
|
|
int i;
|
|
|
|
if (!s->memcg_params)
|
|
return;
|
|
if (!s->memcg_params->is_root_cache)
|
|
return;
|
|
|
|
/*
|
|
* If the cache is being destroyed, we trust that there is no one else
|
|
* requesting objects from it. Even if there are, the sanity checks in
|
|
* kmem_cache_destroy should caught this ill-case.
|
|
*
|
|
* Still, we don't want anyone else freeing memcg_caches under our
|
|
* noses, which can happen if a new memcg comes to life. As usual,
|
|
* we'll take the set_limit_mutex to protect ourselves against this.
|
|
*/
|
|
mutex_lock(&set_limit_mutex);
|
|
for (i = 0; i < memcg_limited_groups_array_size; i++) {
|
|
c = s->memcg_params->memcg_caches[i];
|
|
if (!c)
|
|
continue;
|
|
|
|
/*
|
|
* We will now manually delete the caches, so to avoid races
|
|
* we need to cancel all pending destruction workers and
|
|
* proceed with destruction ourselves.
|
|
*
|
|
* kmem_cache_destroy() will call kmem_cache_shrink internally,
|
|
* and that could spawn the workers again: it is likely that
|
|
* the cache still have active pages until this very moment.
|
|
* This would lead us back to mem_cgroup_destroy_cache.
|
|
*
|
|
* But that will not execute at all if the "dead" flag is not
|
|
* set, so flip it down to guarantee we are in control.
|
|
*/
|
|
c->memcg_params->dead = false;
|
|
cancel_work_sync(&c->memcg_params->destroy);
|
|
kmem_cache_destroy(c);
|
|
}
|
|
mutex_unlock(&set_limit_mutex);
|
|
}
|
|
|
|
struct create_work {
|
|
struct mem_cgroup *memcg;
|
|
struct kmem_cache *cachep;
|
|
struct work_struct work;
|
|
};
|
|
|
|
static void mem_cgroup_destroy_all_caches(struct mem_cgroup *memcg)
|
|
{
|
|
struct kmem_cache *cachep;
|
|
struct memcg_cache_params *params;
|
|
|
|
if (!memcg_kmem_is_active(memcg))
|
|
return;
|
|
|
|
mutex_lock(&memcg->slab_caches_mutex);
|
|
list_for_each_entry(params, &memcg->memcg_slab_caches, list) {
|
|
cachep = memcg_params_to_cache(params);
|
|
cachep->memcg_params->dead = true;
|
|
schedule_work(&cachep->memcg_params->destroy);
|
|
}
|
|
mutex_unlock(&memcg->slab_caches_mutex);
|
|
}
|
|
|
|
static void memcg_create_cache_work_func(struct work_struct *w)
|
|
{
|
|
struct create_work *cw;
|
|
|
|
cw = container_of(w, struct create_work, work);
|
|
memcg_create_kmem_cache(cw->memcg, cw->cachep);
|
|
kfree(cw);
|
|
}
|
|
|
|
/*
|
|
* Enqueue the creation of a per-memcg kmem_cache.
|
|
*/
|
|
static void __memcg_create_cache_enqueue(struct mem_cgroup *memcg,
|
|
struct kmem_cache *cachep)
|
|
{
|
|
struct create_work *cw;
|
|
|
|
cw = kmalloc(sizeof(struct create_work), GFP_NOWAIT);
|
|
if (cw == NULL) {
|
|
css_put(&memcg->css);
|
|
return;
|
|
}
|
|
|
|
cw->memcg = memcg;
|
|
cw->cachep = cachep;
|
|
|
|
INIT_WORK(&cw->work, memcg_create_cache_work_func);
|
|
schedule_work(&cw->work);
|
|
}
|
|
|
|
static void memcg_create_cache_enqueue(struct mem_cgroup *memcg,
|
|
struct kmem_cache *cachep)
|
|
{
|
|
/*
|
|
* We need to stop accounting when we kmalloc, because if the
|
|
* corresponding kmalloc cache is not yet created, the first allocation
|
|
* in __memcg_create_cache_enqueue will recurse.
|
|
*
|
|
* However, it is better to enclose the whole function. Depending on
|
|
* the debugging options enabled, INIT_WORK(), for instance, can
|
|
* trigger an allocation. This too, will make us recurse. Because at
|
|
* this point we can't allow ourselves back into memcg_kmem_get_cache,
|
|
* the safest choice is to do it like this, wrapping the whole function.
|
|
*/
|
|
memcg_stop_kmem_account();
|
|
__memcg_create_cache_enqueue(memcg, cachep);
|
|
memcg_resume_kmem_account();
|
|
}
|
|
/*
|
|
* Return the kmem_cache we're supposed to use for a slab allocation.
|
|
* We try to use the current memcg's version of the cache.
|
|
*
|
|
* If the cache does not exist yet, if we are the first user of it,
|
|
* we either create it immediately, if possible, or create it asynchronously
|
|
* in a workqueue.
|
|
* In the latter case, we will let the current allocation go through with
|
|
* the original cache.
|
|
*
|
|
* Can't be called in interrupt context or from kernel threads.
|
|
* This function needs to be called with rcu_read_lock() held.
|
|
*/
|
|
struct kmem_cache *__memcg_kmem_get_cache(struct kmem_cache *cachep,
|
|
gfp_t gfp)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
int idx;
|
|
|
|
VM_BUG_ON(!cachep->memcg_params);
|
|
VM_BUG_ON(!cachep->memcg_params->is_root_cache);
|
|
|
|
if (!current->mm || current->memcg_kmem_skip_account)
|
|
return cachep;
|
|
|
|
rcu_read_lock();
|
|
memcg = mem_cgroup_from_task(rcu_dereference(current->mm->owner));
|
|
|
|
if (!memcg_can_account_kmem(memcg))
|
|
goto out;
|
|
|
|
idx = memcg_cache_id(memcg);
|
|
|
|
/*
|
|
* barrier to mare sure we're always seeing the up to date value. The
|
|
* code updating memcg_caches will issue a write barrier to match this.
|
|
*/
|
|
read_barrier_depends();
|
|
if (likely(cachep->memcg_params->memcg_caches[idx])) {
|
|
cachep = cachep->memcg_params->memcg_caches[idx];
|
|
goto out;
|
|
}
|
|
|
|
/* The corresponding put will be done in the workqueue. */
|
|
if (!css_tryget(&memcg->css))
|
|
goto out;
|
|
rcu_read_unlock();
|
|
|
|
/*
|
|
* If we are in a safe context (can wait, and not in interrupt
|
|
* context), we could be be predictable and return right away.
|
|
* This would guarantee that the allocation being performed
|
|
* already belongs in the new cache.
|
|
*
|
|
* However, there are some clashes that can arrive from locking.
|
|
* For instance, because we acquire the slab_mutex while doing
|
|
* kmem_cache_dup, this means no further allocation could happen
|
|
* with the slab_mutex held.
|
|
*
|
|
* Also, because cache creation issue get_online_cpus(), this
|
|
* creates a lock chain: memcg_slab_mutex -> cpu_hotplug_mutex,
|
|
* that ends up reversed during cpu hotplug. (cpuset allocates
|
|
* a bunch of GFP_KERNEL memory during cpuup). Due to all that,
|
|
* better to defer everything.
|
|
*/
|
|
memcg_create_cache_enqueue(memcg, cachep);
|
|
return cachep;
|
|
out:
|
|
rcu_read_unlock();
|
|
return cachep;
|
|
}
|
|
EXPORT_SYMBOL(__memcg_kmem_get_cache);
|
|
|
|
/*
|
|
* We need to verify if the allocation against current->mm->owner's memcg is
|
|
* possible for the given order. But the page is not allocated yet, so we'll
|
|
* need a further commit step to do the final arrangements.
|
|
*
|
|
* It is possible for the task to switch cgroups in this mean time, so at
|
|
* commit time, we can't rely on task conversion any longer. We'll then use
|
|
* the handle argument to return to the caller which cgroup we should commit
|
|
* against. We could also return the memcg directly and avoid the pointer
|
|
* passing, but a boolean return value gives better semantics considering
|
|
* the compiled-out case as well.
|
|
*
|
|
* Returning true means the allocation is possible.
|
|
*/
|
|
bool
|
|
__memcg_kmem_newpage_charge(gfp_t gfp, struct mem_cgroup **_memcg, int order)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
int ret;
|
|
|
|
*_memcg = NULL;
|
|
|
|
/*
|
|
* Disabling accounting is only relevant for some specific memcg
|
|
* internal allocations. Therefore we would initially not have such
|
|
* check here, since direct calls to the page allocator that are marked
|
|
* with GFP_KMEMCG only happen outside memcg core. We are mostly
|
|
* concerned with cache allocations, and by having this test at
|
|
* memcg_kmem_get_cache, we are already able to relay the allocation to
|
|
* the root cache and bypass the memcg cache altogether.
|
|
*
|
|
* There is one exception, though: the SLUB allocator does not create
|
|
* large order caches, but rather service large kmallocs directly from
|
|
* the page allocator. Therefore, the following sequence when backed by
|
|
* the SLUB allocator:
|
|
*
|
|
* memcg_stop_kmem_account();
|
|
* kmalloc(<large_number>)
|
|
* memcg_resume_kmem_account();
|
|
*
|
|
* would effectively ignore the fact that we should skip accounting,
|
|
* since it will drive us directly to this function without passing
|
|
* through the cache selector memcg_kmem_get_cache. Such large
|
|
* allocations are extremely rare but can happen, for instance, for the
|
|
* cache arrays. We bring this test here.
|
|
*/
|
|
if (!current->mm || current->memcg_kmem_skip_account)
|
|
return true;
|
|
|
|
memcg = try_get_mem_cgroup_from_mm(current->mm);
|
|
|
|
/*
|
|
* very rare case described in mem_cgroup_from_task. Unfortunately there
|
|
* isn't much we can do without complicating this too much, and it would
|
|
* be gfp-dependent anyway. Just let it go
|
|
*/
|
|
if (unlikely(!memcg))
|
|
return true;
|
|
|
|
if (!memcg_can_account_kmem(memcg)) {
|
|
css_put(&memcg->css);
|
|
return true;
|
|
}
|
|
|
|
ret = memcg_charge_kmem(memcg, gfp, PAGE_SIZE << order);
|
|
if (!ret)
|
|
*_memcg = memcg;
|
|
|
|
css_put(&memcg->css);
|
|
return (ret == 0);
|
|
}
|
|
|
|
void __memcg_kmem_commit_charge(struct page *page, struct mem_cgroup *memcg,
|
|
int order)
|
|
{
|
|
struct page_cgroup *pc;
|
|
|
|
VM_BUG_ON(mem_cgroup_is_root(memcg));
|
|
|
|
/* The page allocation failed. Revert */
|
|
if (!page) {
|
|
memcg_uncharge_kmem(memcg, PAGE_SIZE << order);
|
|
return;
|
|
}
|
|
|
|
pc = lookup_page_cgroup(page);
|
|
lock_page_cgroup(pc);
|
|
pc->mem_cgroup = memcg;
|
|
SetPageCgroupUsed(pc);
|
|
unlock_page_cgroup(pc);
|
|
}
|
|
|
|
void __memcg_kmem_uncharge_pages(struct page *page, int order)
|
|
{
|
|
struct mem_cgroup *memcg = NULL;
|
|
struct page_cgroup *pc;
|
|
|
|
|
|
pc = lookup_page_cgroup(page);
|
|
/*
|
|
* Fast unlocked return. Theoretically might have changed, have to
|
|
* check again after locking.
|
|
*/
|
|
if (!PageCgroupUsed(pc))
|
|
return;
|
|
|
|
lock_page_cgroup(pc);
|
|
if (PageCgroupUsed(pc)) {
|
|
memcg = pc->mem_cgroup;
|
|
ClearPageCgroupUsed(pc);
|
|
}
|
|
unlock_page_cgroup(pc);
|
|
|
|
/*
|
|
* We trust that only if there is a memcg associated with the page, it
|
|
* is a valid allocation
|
|
*/
|
|
if (!memcg)
|
|
return;
|
|
|
|
VM_BUG_ON(mem_cgroup_is_root(memcg));
|
|
memcg_uncharge_kmem(memcg, PAGE_SIZE << order);
|
|
}
|
|
#else
|
|
static inline void mem_cgroup_destroy_all_caches(struct mem_cgroup *memcg)
|
|
{
|
|
}
|
|
#endif /* CONFIG_MEMCG_KMEM */
|
|
|
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
|
|
|
|
#define PCGF_NOCOPY_AT_SPLIT (1 << PCG_LOCK | 1 << PCG_MIGRATION)
|
|
/*
|
|
* Because tail pages are not marked as "used", set it. We're under
|
|
* zone->lru_lock, 'splitting on pmd' and compound_lock.
|
|
* charge/uncharge will be never happen and move_account() is done under
|
|
* compound_lock(), so we don't have to take care of races.
|
|
*/
|
|
void mem_cgroup_split_huge_fixup(struct page *head)
|
|
{
|
|
struct page_cgroup *head_pc = lookup_page_cgroup(head);
|
|
struct page_cgroup *pc;
|
|
struct mem_cgroup *memcg;
|
|
int i;
|
|
|
|
if (mem_cgroup_disabled())
|
|
return;
|
|
|
|
memcg = head_pc->mem_cgroup;
|
|
for (i = 1; i < HPAGE_PMD_NR; i++) {
|
|
pc = head_pc + i;
|
|
pc->mem_cgroup = memcg;
|
|
smp_wmb();/* see __commit_charge() */
|
|
pc->flags = head_pc->flags & ~PCGF_NOCOPY_AT_SPLIT;
|
|
}
|
|
__this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_RSS_HUGE],
|
|
HPAGE_PMD_NR);
|
|
}
|
|
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
|
|
|
|
static inline
|
|
void mem_cgroup_move_account_page_stat(struct mem_cgroup *from,
|
|
struct mem_cgroup *to,
|
|
unsigned int nr_pages,
|
|
enum mem_cgroup_stat_index idx)
|
|
{
|
|
/* Update stat data for mem_cgroup */
|
|
preempt_disable();
|
|
__this_cpu_sub(from->stat->count[idx], nr_pages);
|
|
__this_cpu_add(to->stat->count[idx], nr_pages);
|
|
preempt_enable();
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_move_account - move account of the page
|
|
* @page: the page
|
|
* @nr_pages: number of regular pages (>1 for huge pages)
|
|
* @pc: page_cgroup of the page.
|
|
* @from: mem_cgroup which the page is moved from.
|
|
* @to: mem_cgroup which the page is moved to. @from != @to.
|
|
*
|
|
* The caller must confirm following.
|
|
* - page is not on LRU (isolate_page() is useful.)
|
|
* - compound_lock is held when nr_pages > 1
|
|
*
|
|
* This function doesn't do "charge" to new cgroup and doesn't do "uncharge"
|
|
* from old cgroup.
|
|
*/
|
|
static int mem_cgroup_move_account(struct page *page,
|
|
unsigned int nr_pages,
|
|
struct page_cgroup *pc,
|
|
struct mem_cgroup *from,
|
|
struct mem_cgroup *to)
|
|
{
|
|
unsigned long flags;
|
|
int ret;
|
|
bool anon = PageAnon(page);
|
|
|
|
VM_BUG_ON(from == to);
|
|
VM_BUG_ON(PageLRU(page));
|
|
/*
|
|
* The page is isolated from LRU. So, collapse function
|
|
* will not handle this page. But page splitting can happen.
|
|
* Do this check under compound_page_lock(). The caller should
|
|
* hold it.
|
|
*/
|
|
ret = -EBUSY;
|
|
if (nr_pages > 1 && !PageTransHuge(page))
|
|
goto out;
|
|
|
|
lock_page_cgroup(pc);
|
|
|
|
ret = -EINVAL;
|
|
if (!PageCgroupUsed(pc) || pc->mem_cgroup != from)
|
|
goto unlock;
|
|
|
|
move_lock_mem_cgroup(from, &flags);
|
|
|
|
if (!anon && page_mapped(page))
|
|
mem_cgroup_move_account_page_stat(from, to, nr_pages,
|
|
MEM_CGROUP_STAT_FILE_MAPPED);
|
|
|
|
if (PageWriteback(page))
|
|
mem_cgroup_move_account_page_stat(from, to, nr_pages,
|
|
MEM_CGROUP_STAT_WRITEBACK);
|
|
|
|
mem_cgroup_charge_statistics(from, page, anon, -nr_pages);
|
|
|
|
/* caller should have done css_get */
|
|
pc->mem_cgroup = to;
|
|
mem_cgroup_charge_statistics(to, page, anon, nr_pages);
|
|
move_unlock_mem_cgroup(from, &flags);
|
|
ret = 0;
|
|
unlock:
|
|
unlock_page_cgroup(pc);
|
|
/*
|
|
* check events
|
|
*/
|
|
memcg_check_events(to, page);
|
|
memcg_check_events(from, page);
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_move_parent - moves page to the parent group
|
|
* @page: the page to move
|
|
* @pc: page_cgroup of the page
|
|
* @child: page's cgroup
|
|
*
|
|
* move charges to its parent or the root cgroup if the group has no
|
|
* parent (aka use_hierarchy==0).
|
|
* Although this might fail (get_page_unless_zero, isolate_lru_page or
|
|
* mem_cgroup_move_account fails) the failure is always temporary and
|
|
* it signals a race with a page removal/uncharge or migration. In the
|
|
* first case the page is on the way out and it will vanish from the LRU
|
|
* on the next attempt and the call should be retried later.
|
|
* Isolation from the LRU fails only if page has been isolated from
|
|
* the LRU since we looked at it and that usually means either global
|
|
* reclaim or migration going on. The page will either get back to the
|
|
* LRU or vanish.
|
|
* Finaly mem_cgroup_move_account fails only if the page got uncharged
|
|
* (!PageCgroupUsed) or moved to a different group. The page will
|
|
* disappear in the next attempt.
|
|
*/
|
|
static int mem_cgroup_move_parent(struct page *page,
|
|
struct page_cgroup *pc,
|
|
struct mem_cgroup *child)
|
|
{
|
|
struct mem_cgroup *parent;
|
|
unsigned int nr_pages;
|
|
unsigned long uninitialized_var(flags);
|
|
int ret;
|
|
|
|
VM_BUG_ON(mem_cgroup_is_root(child));
|
|
|
|
ret = -EBUSY;
|
|
if (!get_page_unless_zero(page))
|
|
goto out;
|
|
if (isolate_lru_page(page))
|
|
goto put;
|
|
|
|
nr_pages = hpage_nr_pages(page);
|
|
|
|
parent = parent_mem_cgroup(child);
|
|
/*
|
|
* If no parent, move charges to root cgroup.
|
|
*/
|
|
if (!parent)
|
|
parent = root_mem_cgroup;
|
|
|
|
if (nr_pages > 1) {
|
|
VM_BUG_ON(!PageTransHuge(page));
|
|
flags = compound_lock_irqsave(page);
|
|
}
|
|
|
|
ret = mem_cgroup_move_account(page, nr_pages,
|
|
pc, child, parent);
|
|
if (!ret)
|
|
__mem_cgroup_cancel_local_charge(child, nr_pages);
|
|
|
|
if (nr_pages > 1)
|
|
compound_unlock_irqrestore(page, flags);
|
|
putback_lru_page(page);
|
|
put:
|
|
put_page(page);
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Charge the memory controller for page usage.
|
|
* Return
|
|
* 0 if the charge was successful
|
|
* < 0 if the cgroup is over its limit
|
|
*/
|
|
static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
|
|
gfp_t gfp_mask, enum charge_type ctype)
|
|
{
|
|
struct mem_cgroup *memcg = NULL;
|
|
unsigned int nr_pages = 1;
|
|
bool oom = true;
|
|
int ret;
|
|
|
|
if (PageTransHuge(page)) {
|
|
nr_pages <<= compound_order(page);
|
|
VM_BUG_ON(!PageTransHuge(page));
|
|
/*
|
|
* Never OOM-kill a process for a huge page. The
|
|
* fault handler will fall back to regular pages.
|
|
*/
|
|
oom = false;
|
|
}
|
|
|
|
ret = __mem_cgroup_try_charge(mm, gfp_mask, nr_pages, &memcg, oom);
|
|
if (ret == -ENOMEM)
|
|
return ret;
|
|
__mem_cgroup_commit_charge(memcg, page, nr_pages, ctype, false);
|
|
return 0;
|
|
}
|
|
|
|
int mem_cgroup_newpage_charge(struct page *page,
|
|
struct mm_struct *mm, gfp_t gfp_mask)
|
|
{
|
|
if (mem_cgroup_disabled())
|
|
return 0;
|
|
VM_BUG_ON(page_mapped(page));
|
|
VM_BUG_ON(page->mapping && !PageAnon(page));
|
|
VM_BUG_ON(!mm);
|
|
return mem_cgroup_charge_common(page, mm, gfp_mask,
|
|
MEM_CGROUP_CHARGE_TYPE_ANON);
|
|
}
|
|
|
|
/*
|
|
* While swap-in, try_charge -> commit or cancel, the page is locked.
|
|
* And when try_charge() successfully returns, one refcnt to memcg without
|
|
* struct page_cgroup is acquired. This refcnt will be consumed by
|
|
* "commit()" or removed by "cancel()"
|
|
*/
|
|
static int __mem_cgroup_try_charge_swapin(struct mm_struct *mm,
|
|
struct page *page,
|
|
gfp_t mask,
|
|
struct mem_cgroup **memcgp)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
struct page_cgroup *pc;
|
|
int ret;
|
|
|
|
pc = lookup_page_cgroup(page);
|
|
/*
|
|
* Every swap fault against a single page tries to charge the
|
|
* page, bail as early as possible. shmem_unuse() encounters
|
|
* already charged pages, too. The USED bit is protected by
|
|
* the page lock, which serializes swap cache removal, which
|
|
* in turn serializes uncharging.
|
|
*/
|
|
if (PageCgroupUsed(pc))
|
|
return 0;
|
|
if (!do_swap_account)
|
|
goto charge_cur_mm;
|
|
memcg = try_get_mem_cgroup_from_page(page);
|
|
if (!memcg)
|
|
goto charge_cur_mm;
|
|
*memcgp = memcg;
|
|
ret = __mem_cgroup_try_charge(NULL, mask, 1, memcgp, true);
|
|
css_put(&memcg->css);
|
|
if (ret == -EINTR)
|
|
ret = 0;
|
|
return ret;
|
|
charge_cur_mm:
|
|
ret = __mem_cgroup_try_charge(mm, mask, 1, memcgp, true);
|
|
if (ret == -EINTR)
|
|
ret = 0;
|
|
return ret;
|
|
}
|
|
|
|
int mem_cgroup_try_charge_swapin(struct mm_struct *mm, struct page *page,
|
|
gfp_t gfp_mask, struct mem_cgroup **memcgp)
|
|
{
|
|
*memcgp = NULL;
|
|
if (mem_cgroup_disabled())
|
|
return 0;
|
|
/*
|
|
* A racing thread's fault, or swapoff, may have already
|
|
* updated the pte, and even removed page from swap cache: in
|
|
* those cases unuse_pte()'s pte_same() test will fail; but
|
|
* there's also a KSM case which does need to charge the page.
|
|
*/
|
|
if (!PageSwapCache(page)) {
|
|
int ret;
|
|
|
|
ret = __mem_cgroup_try_charge(mm, gfp_mask, 1, memcgp, true);
|
|
if (ret == -EINTR)
|
|
ret = 0;
|
|
return ret;
|
|
}
|
|
return __mem_cgroup_try_charge_swapin(mm, page, gfp_mask, memcgp);
|
|
}
|
|
|
|
void mem_cgroup_cancel_charge_swapin(struct mem_cgroup *memcg)
|
|
{
|
|
if (mem_cgroup_disabled())
|
|
return;
|
|
if (!memcg)
|
|
return;
|
|
__mem_cgroup_cancel_charge(memcg, 1);
|
|
}
|
|
|
|
static void
|
|
__mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *memcg,
|
|
enum charge_type ctype)
|
|
{
|
|
if (mem_cgroup_disabled())
|
|
return;
|
|
if (!memcg)
|
|
return;
|
|
|
|
__mem_cgroup_commit_charge(memcg, page, 1, ctype, true);
|
|
/*
|
|
* Now swap is on-memory. This means this page may be
|
|
* counted both as mem and swap....double count.
|
|
* Fix it by uncharging from memsw. Basically, this SwapCache is stable
|
|
* under lock_page(). But in do_swap_page()::memory.c, reuse_swap_page()
|
|
* may call delete_from_swap_cache() before reach here.
|
|
*/
|
|
if (do_swap_account && PageSwapCache(page)) {
|
|
swp_entry_t ent = {.val = page_private(page)};
|
|
mem_cgroup_uncharge_swap(ent);
|
|
}
|
|
}
|
|
|
|
void mem_cgroup_commit_charge_swapin(struct page *page,
|
|
struct mem_cgroup *memcg)
|
|
{
|
|
__mem_cgroup_commit_charge_swapin(page, memcg,
|
|
MEM_CGROUP_CHARGE_TYPE_ANON);
|
|
}
|
|
|
|
int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
|
|
gfp_t gfp_mask)
|
|
{
|
|
struct mem_cgroup *memcg = NULL;
|
|
enum charge_type type = MEM_CGROUP_CHARGE_TYPE_CACHE;
|
|
int ret;
|
|
|
|
if (mem_cgroup_disabled())
|
|
return 0;
|
|
if (PageCompound(page))
|
|
return 0;
|
|
|
|
if (!PageSwapCache(page))
|
|
ret = mem_cgroup_charge_common(page, mm, gfp_mask, type);
|
|
else { /* page is swapcache/shmem */
|
|
ret = __mem_cgroup_try_charge_swapin(mm, page,
|
|
gfp_mask, &memcg);
|
|
if (!ret)
|
|
__mem_cgroup_commit_charge_swapin(page, memcg, type);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static void mem_cgroup_do_uncharge(struct mem_cgroup *memcg,
|
|
unsigned int nr_pages,
|
|
const enum charge_type ctype)
|
|
{
|
|
struct memcg_batch_info *batch = NULL;
|
|
bool uncharge_memsw = true;
|
|
|
|
/* If swapout, usage of swap doesn't decrease */
|
|
if (!do_swap_account || ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT)
|
|
uncharge_memsw = false;
|
|
|
|
batch = ¤t->memcg_batch;
|
|
/*
|
|
* In usual, we do css_get() when we remember memcg pointer.
|
|
* But in this case, we keep res->usage until end of a series of
|
|
* uncharges. Then, it's ok to ignore memcg's refcnt.
|
|
*/
|
|
if (!batch->memcg)
|
|
batch->memcg = memcg;
|
|
/*
|
|
* do_batch > 0 when unmapping pages or inode invalidate/truncate.
|
|
* In those cases, all pages freed continuously can be expected to be in
|
|
* the same cgroup and we have chance to coalesce uncharges.
|
|
* But we do uncharge one by one if this is killed by OOM(TIF_MEMDIE)
|
|
* because we want to do uncharge as soon as possible.
|
|
*/
|
|
|
|
if (!batch->do_batch || test_thread_flag(TIF_MEMDIE))
|
|
goto direct_uncharge;
|
|
|
|
if (nr_pages > 1)
|
|
goto direct_uncharge;
|
|
|
|
/*
|
|
* In typical case, batch->memcg == mem. This means we can
|
|
* merge a series of uncharges to an uncharge of res_counter.
|
|
* If not, we uncharge res_counter ony by one.
|
|
*/
|
|
if (batch->memcg != memcg)
|
|
goto direct_uncharge;
|
|
/* remember freed charge and uncharge it later */
|
|
batch->nr_pages++;
|
|
if (uncharge_memsw)
|
|
batch->memsw_nr_pages++;
|
|
return;
|
|
direct_uncharge:
|
|
res_counter_uncharge(&memcg->res, nr_pages * PAGE_SIZE);
|
|
if (uncharge_memsw)
|
|
res_counter_uncharge(&memcg->memsw, nr_pages * PAGE_SIZE);
|
|
if (unlikely(batch->memcg != memcg))
|
|
memcg_oom_recover(memcg);
|
|
}
|
|
|
|
/*
|
|
* uncharge if !page_mapped(page)
|
|
*/
|
|
static struct mem_cgroup *
|
|
__mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype,
|
|
bool end_migration)
|
|
{
|
|
struct mem_cgroup *memcg = NULL;
|
|
unsigned int nr_pages = 1;
|
|
struct page_cgroup *pc;
|
|
bool anon;
|
|
|
|
if (mem_cgroup_disabled())
|
|
return NULL;
|
|
|
|
if (PageTransHuge(page)) {
|
|
nr_pages <<= compound_order(page);
|
|
VM_BUG_ON(!PageTransHuge(page));
|
|
}
|
|
/*
|
|
* Check if our page_cgroup is valid
|
|
*/
|
|
pc = lookup_page_cgroup(page);
|
|
if (unlikely(!PageCgroupUsed(pc)))
|
|
return NULL;
|
|
|
|
lock_page_cgroup(pc);
|
|
|
|
memcg = pc->mem_cgroup;
|
|
|
|
if (!PageCgroupUsed(pc))
|
|
goto unlock_out;
|
|
|
|
anon = PageAnon(page);
|
|
|
|
switch (ctype) {
|
|
case MEM_CGROUP_CHARGE_TYPE_ANON:
|
|
/*
|
|
* Generally PageAnon tells if it's the anon statistics to be
|
|
* updated; but sometimes e.g. mem_cgroup_uncharge_page() is
|
|
* used before page reached the stage of being marked PageAnon.
|
|
*/
|
|
anon = true;
|
|
/* fallthrough */
|
|
case MEM_CGROUP_CHARGE_TYPE_DROP:
|
|
/* See mem_cgroup_prepare_migration() */
|
|
if (page_mapped(page))
|
|
goto unlock_out;
|
|
/*
|
|
* Pages under migration may not be uncharged. But
|
|
* end_migration() /must/ be the one uncharging the
|
|
* unused post-migration page and so it has to call
|
|
* here with the migration bit still set. See the
|
|
* res_counter handling below.
|
|
*/
|
|
if (!end_migration && PageCgroupMigration(pc))
|
|
goto unlock_out;
|
|
break;
|
|
case MEM_CGROUP_CHARGE_TYPE_SWAPOUT:
|
|
if (!PageAnon(page)) { /* Shared memory */
|
|
if (page->mapping && !page_is_file_cache(page))
|
|
goto unlock_out;
|
|
} else if (page_mapped(page)) /* Anon */
|
|
goto unlock_out;
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
|
|
mem_cgroup_charge_statistics(memcg, page, anon, -nr_pages);
|
|
|
|
ClearPageCgroupUsed(pc);
|
|
/*
|
|
* pc->mem_cgroup is not cleared here. It will be accessed when it's
|
|
* freed from LRU. This is safe because uncharged page is expected not
|
|
* to be reused (freed soon). Exception is SwapCache, it's handled by
|
|
* special functions.
|
|
*/
|
|
|
|
unlock_page_cgroup(pc);
|
|
/*
|
|
* even after unlock, we have memcg->res.usage here and this memcg
|
|
* will never be freed, so it's safe to call css_get().
|
|
*/
|
|
memcg_check_events(memcg, page);
|
|
if (do_swap_account && ctype == MEM_CGROUP_CHARGE_TYPE_SWAPOUT) {
|
|
mem_cgroup_swap_statistics(memcg, true);
|
|
css_get(&memcg->css);
|
|
}
|
|
/*
|
|
* Migration does not charge the res_counter for the
|
|
* replacement page, so leave it alone when phasing out the
|
|
* page that is unused after the migration.
|
|
*/
|
|
if (!end_migration && !mem_cgroup_is_root(memcg))
|
|
mem_cgroup_do_uncharge(memcg, nr_pages, ctype);
|
|
|
|
return memcg;
|
|
|
|
unlock_out:
|
|
unlock_page_cgroup(pc);
|
|
return NULL;
|
|
}
|
|
|
|
void mem_cgroup_uncharge_page(struct page *page)
|
|
{
|
|
/* early check. */
|
|
if (page_mapped(page))
|
|
return;
|
|
VM_BUG_ON(page->mapping && !PageAnon(page));
|
|
/*
|
|
* If the page is in swap cache, uncharge should be deferred
|
|
* to the swap path, which also properly accounts swap usage
|
|
* and handles memcg lifetime.
|
|
*
|
|
* Note that this check is not stable and reclaim may add the
|
|
* page to swap cache at any time after this. However, if the
|
|
* page is not in swap cache by the time page->mapcount hits
|
|
* 0, there won't be any page table references to the swap
|
|
* slot, and reclaim will free it and not actually write the
|
|
* page to disk.
|
|
*/
|
|
if (PageSwapCache(page))
|
|
return;
|
|
__mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_ANON, false);
|
|
}
|
|
|
|
void mem_cgroup_uncharge_cache_page(struct page *page)
|
|
{
|
|
VM_BUG_ON(page_mapped(page));
|
|
VM_BUG_ON(page->mapping);
|
|
__mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE, false);
|
|
}
|
|
|
|
/*
|
|
* Batch_start/batch_end is called in unmap_page_range/invlidate/trucate.
|
|
* In that cases, pages are freed continuously and we can expect pages
|
|
* are in the same memcg. All these calls itself limits the number of
|
|
* pages freed at once, then uncharge_start/end() is called properly.
|
|
* This may be called prural(2) times in a context,
|
|
*/
|
|
|
|
void mem_cgroup_uncharge_start(void)
|
|
{
|
|
current->memcg_batch.do_batch++;
|
|
/* We can do nest. */
|
|
if (current->memcg_batch.do_batch == 1) {
|
|
current->memcg_batch.memcg = NULL;
|
|
current->memcg_batch.nr_pages = 0;
|
|
current->memcg_batch.memsw_nr_pages = 0;
|
|
}
|
|
}
|
|
|
|
void mem_cgroup_uncharge_end(void)
|
|
{
|
|
struct memcg_batch_info *batch = ¤t->memcg_batch;
|
|
|
|
if (!batch->do_batch)
|
|
return;
|
|
|
|
batch->do_batch--;
|
|
if (batch->do_batch) /* If stacked, do nothing. */
|
|
return;
|
|
|
|
if (!batch->memcg)
|
|
return;
|
|
/*
|
|
* This "batch->memcg" is valid without any css_get/put etc...
|
|
* bacause we hide charges behind us.
|
|
*/
|
|
if (batch->nr_pages)
|
|
res_counter_uncharge(&batch->memcg->res,
|
|
batch->nr_pages * PAGE_SIZE);
|
|
if (batch->memsw_nr_pages)
|
|
res_counter_uncharge(&batch->memcg->memsw,
|
|
batch->memsw_nr_pages * PAGE_SIZE);
|
|
memcg_oom_recover(batch->memcg);
|
|
/* forget this pointer (for sanity check) */
|
|
batch->memcg = NULL;
|
|
}
|
|
|
|
#ifdef CONFIG_SWAP
|
|
/*
|
|
* called after __delete_from_swap_cache() and drop "page" account.
|
|
* memcg information is recorded to swap_cgroup of "ent"
|
|
*/
|
|
void
|
|
mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
int ctype = MEM_CGROUP_CHARGE_TYPE_SWAPOUT;
|
|
|
|
if (!swapout) /* this was a swap cache but the swap is unused ! */
|
|
ctype = MEM_CGROUP_CHARGE_TYPE_DROP;
|
|
|
|
memcg = __mem_cgroup_uncharge_common(page, ctype, false);
|
|
|
|
/*
|
|
* record memcg information, if swapout && memcg != NULL,
|
|
* css_get() was called in uncharge().
|
|
*/
|
|
if (do_swap_account && swapout && memcg)
|
|
swap_cgroup_record(ent, css_id(&memcg->css));
|
|
}
|
|
#endif
|
|
|
|
#ifdef CONFIG_MEMCG_SWAP
|
|
/*
|
|
* called from swap_entry_free(). remove record in swap_cgroup and
|
|
* uncharge "memsw" account.
|
|
*/
|
|
void mem_cgroup_uncharge_swap(swp_entry_t ent)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
unsigned short id;
|
|
|
|
if (!do_swap_account)
|
|
return;
|
|
|
|
id = swap_cgroup_record(ent, 0);
|
|
rcu_read_lock();
|
|
memcg = mem_cgroup_lookup(id);
|
|
if (memcg) {
|
|
/*
|
|
* We uncharge this because swap is freed.
|
|
* This memcg can be obsolete one. We avoid calling css_tryget
|
|
*/
|
|
if (!mem_cgroup_is_root(memcg))
|
|
res_counter_uncharge(&memcg->memsw, PAGE_SIZE);
|
|
mem_cgroup_swap_statistics(memcg, false);
|
|
css_put(&memcg->css);
|
|
}
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_move_swap_account - move swap charge and swap_cgroup's record.
|
|
* @entry: swap entry to be moved
|
|
* @from: mem_cgroup which the entry is moved from
|
|
* @to: mem_cgroup which the entry is moved to
|
|
*
|
|
* It succeeds only when the swap_cgroup's record for this entry is the same
|
|
* as the mem_cgroup's id of @from.
|
|
*
|
|
* Returns 0 on success, -EINVAL on failure.
|
|
*
|
|
* The caller must have charged to @to, IOW, called res_counter_charge() about
|
|
* both res and memsw, and called css_get().
|
|
*/
|
|
static int mem_cgroup_move_swap_account(swp_entry_t entry,
|
|
struct mem_cgroup *from, struct mem_cgroup *to)
|
|
{
|
|
unsigned short old_id, new_id;
|
|
|
|
old_id = css_id(&from->css);
|
|
new_id = css_id(&to->css);
|
|
|
|
if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) {
|
|
mem_cgroup_swap_statistics(from, false);
|
|
mem_cgroup_swap_statistics(to, true);
|
|
/*
|
|
* This function is only called from task migration context now.
|
|
* It postpones res_counter and refcount handling till the end
|
|
* of task migration(mem_cgroup_clear_mc()) for performance
|
|
* improvement. But we cannot postpone css_get(to) because if
|
|
* the process that has been moved to @to does swap-in, the
|
|
* refcount of @to might be decreased to 0.
|
|
*
|
|
* We are in attach() phase, so the cgroup is guaranteed to be
|
|
* alive, so we can just call css_get().
|
|
*/
|
|
css_get(&to->css);
|
|
return 0;
|
|
}
|
|
return -EINVAL;
|
|
}
|
|
#else
|
|
static inline int mem_cgroup_move_swap_account(swp_entry_t entry,
|
|
struct mem_cgroup *from, struct mem_cgroup *to)
|
|
{
|
|
return -EINVAL;
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* Before starting migration, account PAGE_SIZE to mem_cgroup that the old
|
|
* page belongs to.
|
|
*/
|
|
void mem_cgroup_prepare_migration(struct page *page, struct page *newpage,
|
|
struct mem_cgroup **memcgp)
|
|
{
|
|
struct mem_cgroup *memcg = NULL;
|
|
unsigned int nr_pages = 1;
|
|
struct page_cgroup *pc;
|
|
enum charge_type ctype;
|
|
|
|
*memcgp = NULL;
|
|
|
|
if (mem_cgroup_disabled())
|
|
return;
|
|
|
|
if (PageTransHuge(page))
|
|
nr_pages <<= compound_order(page);
|
|
|
|
pc = lookup_page_cgroup(page);
|
|
lock_page_cgroup(pc);
|
|
if (PageCgroupUsed(pc)) {
|
|
memcg = pc->mem_cgroup;
|
|
css_get(&memcg->css);
|
|
/*
|
|
* At migrating an anonymous page, its mapcount goes down
|
|
* to 0 and uncharge() will be called. But, even if it's fully
|
|
* unmapped, migration may fail and this page has to be
|
|
* charged again. We set MIGRATION flag here and delay uncharge
|
|
* until end_migration() is called
|
|
*
|
|
* Corner Case Thinking
|
|
* A)
|
|
* When the old page was mapped as Anon and it's unmap-and-freed
|
|
* while migration was ongoing.
|
|
* If unmap finds the old page, uncharge() of it will be delayed
|
|
* until end_migration(). If unmap finds a new page, it's
|
|
* uncharged when it make mapcount to be 1->0. If unmap code
|
|
* finds swap_migration_entry, the new page will not be mapped
|
|
* and end_migration() will find it(mapcount==0).
|
|
*
|
|
* B)
|
|
* When the old page was mapped but migraion fails, the kernel
|
|
* remaps it. A charge for it is kept by MIGRATION flag even
|
|
* if mapcount goes down to 0. We can do remap successfully
|
|
* without charging it again.
|
|
*
|
|
* C)
|
|
* The "old" page is under lock_page() until the end of
|
|
* migration, so, the old page itself will not be swapped-out.
|
|
* If the new page is swapped out before end_migraton, our
|
|
* hook to usual swap-out path will catch the event.
|
|
*/
|
|
if (PageAnon(page))
|
|
SetPageCgroupMigration(pc);
|
|
}
|
|
unlock_page_cgroup(pc);
|
|
/*
|
|
* If the page is not charged at this point,
|
|
* we return here.
|
|
*/
|
|
if (!memcg)
|
|
return;
|
|
|
|
*memcgp = memcg;
|
|
/*
|
|
* We charge new page before it's used/mapped. So, even if unlock_page()
|
|
* is called before end_migration, we can catch all events on this new
|
|
* page. In the case new page is migrated but not remapped, new page's
|
|
* mapcount will be finally 0 and we call uncharge in end_migration().
|
|
*/
|
|
if (PageAnon(page))
|
|
ctype = MEM_CGROUP_CHARGE_TYPE_ANON;
|
|
else
|
|
ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
|
|
/*
|
|
* The page is committed to the memcg, but it's not actually
|
|
* charged to the res_counter since we plan on replacing the
|
|
* old one and only one page is going to be left afterwards.
|
|
*/
|
|
__mem_cgroup_commit_charge(memcg, newpage, nr_pages, ctype, false);
|
|
}
|
|
|
|
/* remove redundant charge if migration failed*/
|
|
void mem_cgroup_end_migration(struct mem_cgroup *memcg,
|
|
struct page *oldpage, struct page *newpage, bool migration_ok)
|
|
{
|
|
struct page *used, *unused;
|
|
struct page_cgroup *pc;
|
|
bool anon;
|
|
|
|
if (!memcg)
|
|
return;
|
|
|
|
if (!migration_ok) {
|
|
used = oldpage;
|
|
unused = newpage;
|
|
} else {
|
|
used = newpage;
|
|
unused = oldpage;
|
|
}
|
|
anon = PageAnon(used);
|
|
__mem_cgroup_uncharge_common(unused,
|
|
anon ? MEM_CGROUP_CHARGE_TYPE_ANON
|
|
: MEM_CGROUP_CHARGE_TYPE_CACHE,
|
|
true);
|
|
css_put(&memcg->css);
|
|
/*
|
|
* We disallowed uncharge of pages under migration because mapcount
|
|
* of the page goes down to zero, temporarly.
|
|
* Clear the flag and check the page should be charged.
|
|
*/
|
|
pc = lookup_page_cgroup(oldpage);
|
|
lock_page_cgroup(pc);
|
|
ClearPageCgroupMigration(pc);
|
|
unlock_page_cgroup(pc);
|
|
|
|
/*
|
|
* If a page is a file cache, radix-tree replacement is very atomic
|
|
* and we can skip this check. When it was an Anon page, its mapcount
|
|
* goes down to 0. But because we added MIGRATION flage, it's not
|
|
* uncharged yet. There are several case but page->mapcount check
|
|
* and USED bit check in mem_cgroup_uncharge_page() will do enough
|
|
* check. (see prepare_charge() also)
|
|
*/
|
|
if (anon)
|
|
mem_cgroup_uncharge_page(used);
|
|
}
|
|
|
|
/*
|
|
* At replace page cache, newpage is not under any memcg but it's on
|
|
* LRU. So, this function doesn't touch res_counter but handles LRU
|
|
* in correct way. Both pages are locked so we cannot race with uncharge.
|
|
*/
|
|
void mem_cgroup_replace_page_cache(struct page *oldpage,
|
|
struct page *newpage)
|
|
{
|
|
struct mem_cgroup *memcg = NULL;
|
|
struct page_cgroup *pc;
|
|
enum charge_type type = MEM_CGROUP_CHARGE_TYPE_CACHE;
|
|
|
|
if (mem_cgroup_disabled())
|
|
return;
|
|
|
|
pc = lookup_page_cgroup(oldpage);
|
|
/* fix accounting on old pages */
|
|
lock_page_cgroup(pc);
|
|
if (PageCgroupUsed(pc)) {
|
|
memcg = pc->mem_cgroup;
|
|
mem_cgroup_charge_statistics(memcg, oldpage, false, -1);
|
|
ClearPageCgroupUsed(pc);
|
|
}
|
|
unlock_page_cgroup(pc);
|
|
|
|
/*
|
|
* When called from shmem_replace_page(), in some cases the
|
|
* oldpage has already been charged, and in some cases not.
|
|
*/
|
|
if (!memcg)
|
|
return;
|
|
/*
|
|
* Even if newpage->mapping was NULL before starting replacement,
|
|
* the newpage may be on LRU(or pagevec for LRU) already. We lock
|
|
* LRU while we overwrite pc->mem_cgroup.
|
|
*/
|
|
__mem_cgroup_commit_charge(memcg, newpage, 1, type, true);
|
|
}
|
|
|
|
#ifdef CONFIG_DEBUG_VM
|
|
static struct page_cgroup *lookup_page_cgroup_used(struct page *page)
|
|
{
|
|
struct page_cgroup *pc;
|
|
|
|
pc = lookup_page_cgroup(page);
|
|
/*
|
|
* Can be NULL while feeding pages into the page allocator for
|
|
* the first time, i.e. during boot or memory hotplug;
|
|
* or when mem_cgroup_disabled().
|
|
*/
|
|
if (likely(pc) && PageCgroupUsed(pc))
|
|
return pc;
|
|
return NULL;
|
|
}
|
|
|
|
bool mem_cgroup_bad_page_check(struct page *page)
|
|
{
|
|
if (mem_cgroup_disabled())
|
|
return false;
|
|
|
|
return lookup_page_cgroup_used(page) != NULL;
|
|
}
|
|
|
|
void mem_cgroup_print_bad_page(struct page *page)
|
|
{
|
|
struct page_cgroup *pc;
|
|
|
|
pc = lookup_page_cgroup_used(page);
|
|
if (pc) {
|
|
pr_alert("pc:%p pc->flags:%lx pc->mem_cgroup:%p\n",
|
|
pc, pc->flags, pc->mem_cgroup);
|
|
}
|
|
}
|
|
#endif
|
|
|
|
static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
|
|
unsigned long long val)
|
|
{
|
|
int retry_count;
|
|
u64 memswlimit, memlimit;
|
|
int ret = 0;
|
|
int children = mem_cgroup_count_children(memcg);
|
|
u64 curusage, oldusage;
|
|
int enlarge;
|
|
|
|
/*
|
|
* For keeping hierarchical_reclaim simple, how long we should retry
|
|
* is depends on callers. We set our retry-count to be function
|
|
* of # of children which we should visit in this loop.
|
|
*/
|
|
retry_count = MEM_CGROUP_RECLAIM_RETRIES * children;
|
|
|
|
oldusage = res_counter_read_u64(&memcg->res, RES_USAGE);
|
|
|
|
enlarge = 0;
|
|
while (retry_count) {
|
|
if (signal_pending(current)) {
|
|
ret = -EINTR;
|
|
break;
|
|
}
|
|
/*
|
|
* Rather than hide all in some function, I do this in
|
|
* open coded manner. You see what this really does.
|
|
* We have to guarantee memcg->res.limit <= memcg->memsw.limit.
|
|
*/
|
|
mutex_lock(&set_limit_mutex);
|
|
memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
|
|
if (memswlimit < val) {
|
|
ret = -EINVAL;
|
|
mutex_unlock(&set_limit_mutex);
|
|
break;
|
|
}
|
|
|
|
memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT);
|
|
if (memlimit < val)
|
|
enlarge = 1;
|
|
|
|
ret = res_counter_set_limit(&memcg->res, val);
|
|
if (!ret) {
|
|
if (memswlimit == val)
|
|
memcg->memsw_is_minimum = true;
|
|
else
|
|
memcg->memsw_is_minimum = false;
|
|
}
|
|
mutex_unlock(&set_limit_mutex);
|
|
|
|
if (!ret)
|
|
break;
|
|
|
|
mem_cgroup_reclaim(memcg, GFP_KERNEL,
|
|
MEM_CGROUP_RECLAIM_SHRINK);
|
|
curusage = res_counter_read_u64(&memcg->res, RES_USAGE);
|
|
/* Usage is reduced ? */
|
|
if (curusage >= oldusage)
|
|
retry_count--;
|
|
else
|
|
oldusage = curusage;
|
|
}
|
|
if (!ret && enlarge)
|
|
memcg_oom_recover(memcg);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
|
|
unsigned long long val)
|
|
{
|
|
int retry_count;
|
|
u64 memlimit, memswlimit, oldusage, curusage;
|
|
int children = mem_cgroup_count_children(memcg);
|
|
int ret = -EBUSY;
|
|
int enlarge = 0;
|
|
|
|
/* see mem_cgroup_resize_res_limit */
|
|
retry_count = children * MEM_CGROUP_RECLAIM_RETRIES;
|
|
oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
|
|
while (retry_count) {
|
|
if (signal_pending(current)) {
|
|
ret = -EINTR;
|
|
break;
|
|
}
|
|
/*
|
|
* Rather than hide all in some function, I do this in
|
|
* open coded manner. You see what this really does.
|
|
* We have to guarantee memcg->res.limit <= memcg->memsw.limit.
|
|
*/
|
|
mutex_lock(&set_limit_mutex);
|
|
memlimit = res_counter_read_u64(&memcg->res, RES_LIMIT);
|
|
if (memlimit > val) {
|
|
ret = -EINVAL;
|
|
mutex_unlock(&set_limit_mutex);
|
|
break;
|
|
}
|
|
memswlimit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
|
|
if (memswlimit < val)
|
|
enlarge = 1;
|
|
ret = res_counter_set_limit(&memcg->memsw, val);
|
|
if (!ret) {
|
|
if (memlimit == val)
|
|
memcg->memsw_is_minimum = true;
|
|
else
|
|
memcg->memsw_is_minimum = false;
|
|
}
|
|
mutex_unlock(&set_limit_mutex);
|
|
|
|
if (!ret)
|
|
break;
|
|
|
|
mem_cgroup_reclaim(memcg, GFP_KERNEL,
|
|
MEM_CGROUP_RECLAIM_NOSWAP |
|
|
MEM_CGROUP_RECLAIM_SHRINK);
|
|
curusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
|
|
/* Usage is reduced ? */
|
|
if (curusage >= oldusage)
|
|
retry_count--;
|
|
else
|
|
oldusage = curusage;
|
|
}
|
|
if (!ret && enlarge)
|
|
memcg_oom_recover(memcg);
|
|
return ret;
|
|
}
|
|
|
|
unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
|
|
gfp_t gfp_mask,
|
|
unsigned long *total_scanned)
|
|
{
|
|
unsigned long nr_reclaimed = 0;
|
|
struct mem_cgroup_per_zone *mz, *next_mz = NULL;
|
|
unsigned long reclaimed;
|
|
int loop = 0;
|
|
struct mem_cgroup_tree_per_zone *mctz;
|
|
unsigned long long excess;
|
|
unsigned long nr_scanned;
|
|
|
|
if (order > 0)
|
|
return 0;
|
|
|
|
mctz = soft_limit_tree_node_zone(zone_to_nid(zone), zone_idx(zone));
|
|
/*
|
|
* This loop can run a while, specially if mem_cgroup's continuously
|
|
* keep exceeding their soft limit and putting the system under
|
|
* pressure
|
|
*/
|
|
do {
|
|
if (next_mz)
|
|
mz = next_mz;
|
|
else
|
|
mz = mem_cgroup_largest_soft_limit_node(mctz);
|
|
if (!mz)
|
|
break;
|
|
|
|
nr_scanned = 0;
|
|
reclaimed = mem_cgroup_soft_reclaim(mz->memcg, zone,
|
|
gfp_mask, &nr_scanned);
|
|
nr_reclaimed += reclaimed;
|
|
*total_scanned += nr_scanned;
|
|
spin_lock(&mctz->lock);
|
|
|
|
/*
|
|
* If we failed to reclaim anything from this memory cgroup
|
|
* it is time to move on to the next cgroup
|
|
*/
|
|
next_mz = NULL;
|
|
if (!reclaimed) {
|
|
do {
|
|
/*
|
|
* Loop until we find yet another one.
|
|
*
|
|
* By the time we get the soft_limit lock
|
|
* again, someone might have aded the
|
|
* group back on the RB tree. Iterate to
|
|
* make sure we get a different mem.
|
|
* mem_cgroup_largest_soft_limit_node returns
|
|
* NULL if no other cgroup is present on
|
|
* the tree
|
|
*/
|
|
next_mz =
|
|
__mem_cgroup_largest_soft_limit_node(mctz);
|
|
if (next_mz == mz)
|
|
css_put(&next_mz->memcg->css);
|
|
else /* next_mz == NULL or other memcg */
|
|
break;
|
|
} while (1);
|
|
}
|
|
__mem_cgroup_remove_exceeded(mz->memcg, mz, mctz);
|
|
excess = res_counter_soft_limit_excess(&mz->memcg->res);
|
|
/*
|
|
* One school of thought says that we should not add
|
|
* back the node to the tree if reclaim returns 0.
|
|
* But our reclaim could return 0, simply because due
|
|
* to priority we are exposing a smaller subset of
|
|
* memory to reclaim from. Consider this as a longer
|
|
* term TODO.
|
|
*/
|
|
/* If excess == 0, no tree ops */
|
|
__mem_cgroup_insert_exceeded(mz->memcg, mz, mctz, excess);
|
|
spin_unlock(&mctz->lock);
|
|
css_put(&mz->memcg->css);
|
|
loop++;
|
|
/*
|
|
* Could not reclaim anything and there are no more
|
|
* mem cgroups to try or we seem to be looping without
|
|
* reclaiming anything.
|
|
*/
|
|
if (!nr_reclaimed &&
|
|
(next_mz == NULL ||
|
|
loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS))
|
|
break;
|
|
} while (!nr_reclaimed);
|
|
if (next_mz)
|
|
css_put(&next_mz->memcg->css);
|
|
return nr_reclaimed;
|
|
}
|
|
|
|
/**
|
|
* mem_cgroup_force_empty_list - clears LRU of a group
|
|
* @memcg: group to clear
|
|
* @node: NUMA node
|
|
* @zid: zone id
|
|
* @lru: lru to to clear
|
|
*
|
|
* Traverse a specified page_cgroup list and try to drop them all. This doesn't
|
|
* reclaim the pages page themselves - pages are moved to the parent (or root)
|
|
* group.
|
|
*/
|
|
static void mem_cgroup_force_empty_list(struct mem_cgroup *memcg,
|
|
int node, int zid, enum lru_list lru)
|
|
{
|
|
struct lruvec *lruvec;
|
|
unsigned long flags;
|
|
struct list_head *list;
|
|
struct page *busy;
|
|
struct zone *zone;
|
|
|
|
zone = &NODE_DATA(node)->node_zones[zid];
|
|
lruvec = mem_cgroup_zone_lruvec(zone, memcg);
|
|
list = &lruvec->lists[lru];
|
|
|
|
busy = NULL;
|
|
do {
|
|
struct page_cgroup *pc;
|
|
struct page *page;
|
|
|
|
spin_lock_irqsave(&zone->lru_lock, flags);
|
|
if (list_empty(list)) {
|
|
spin_unlock_irqrestore(&zone->lru_lock, flags);
|
|
break;
|
|
}
|
|
page = list_entry(list->prev, struct page, lru);
|
|
if (busy == page) {
|
|
list_move(&page->lru, list);
|
|
busy = NULL;
|
|
spin_unlock_irqrestore(&zone->lru_lock, flags);
|
|
continue;
|
|
}
|
|
spin_unlock_irqrestore(&zone->lru_lock, flags);
|
|
|
|
pc = lookup_page_cgroup(page);
|
|
|
|
if (mem_cgroup_move_parent(page, pc, memcg)) {
|
|
/* found lock contention or "pc" is obsolete. */
|
|
busy = page;
|
|
cond_resched();
|
|
} else
|
|
busy = NULL;
|
|
} while (!list_empty(list));
|
|
}
|
|
|
|
/*
|
|
* make mem_cgroup's charge to be 0 if there is no task by moving
|
|
* all the charges and pages to the parent.
|
|
* This enables deleting this mem_cgroup.
|
|
*
|
|
* Caller is responsible for holding css reference on the memcg.
|
|
*/
|
|
static void mem_cgroup_reparent_charges(struct mem_cgroup *memcg)
|
|
{
|
|
int node, zid;
|
|
u64 usage;
|
|
|
|
do {
|
|
/* This is for making all *used* pages to be on LRU. */
|
|
lru_add_drain_all();
|
|
drain_all_stock_sync(memcg);
|
|
mem_cgroup_start_move(memcg);
|
|
for_each_node_state(node, N_MEMORY) {
|
|
for (zid = 0; zid < MAX_NR_ZONES; zid++) {
|
|
enum lru_list lru;
|
|
for_each_lru(lru) {
|
|
mem_cgroup_force_empty_list(memcg,
|
|
node, zid, lru);
|
|
}
|
|
}
|
|
}
|
|
mem_cgroup_end_move(memcg);
|
|
memcg_oom_recover(memcg);
|
|
cond_resched();
|
|
|
|
/*
|
|
* Kernel memory may not necessarily be trackable to a specific
|
|
* process. So they are not migrated, and therefore we can't
|
|
* expect their value to drop to 0 here.
|
|
* Having res filled up with kmem only is enough.
|
|
*
|
|
* This is a safety check because mem_cgroup_force_empty_list
|
|
* could have raced with mem_cgroup_replace_page_cache callers
|
|
* so the lru seemed empty but the page could have been added
|
|
* right after the check. RES_USAGE should be safe as we always
|
|
* charge before adding to the LRU.
|
|
*/
|
|
usage = res_counter_read_u64(&memcg->res, RES_USAGE) -
|
|
res_counter_read_u64(&memcg->kmem, RES_USAGE);
|
|
} while (usage > 0);
|
|
}
|
|
|
|
static inline bool memcg_has_children(struct mem_cgroup *memcg)
|
|
{
|
|
lockdep_assert_held(&memcg_create_mutex);
|
|
/*
|
|
* The lock does not prevent addition or deletion to the list
|
|
* of children, but it prevents a new child from being
|
|
* initialized based on this parent in css_online(), so it's
|
|
* enough to decide whether hierarchically inherited
|
|
* attributes can still be changed or not.
|
|
*/
|
|
return memcg->use_hierarchy &&
|
|
!list_empty(&memcg->css.cgroup->children);
|
|
}
|
|
|
|
/*
|
|
* Reclaims as many pages from the given memcg as possible and moves
|
|
* the rest to the parent.
|
|
*
|
|
* Caller is responsible for holding css reference for memcg.
|
|
*/
|
|
static int mem_cgroup_force_empty(struct mem_cgroup *memcg)
|
|
{
|
|
int nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
|
|
struct cgroup *cgrp = memcg->css.cgroup;
|
|
|
|
/* returns EBUSY if there is a task or if we come here twice. */
|
|
if (cgroup_task_count(cgrp) || !list_empty(&cgrp->children))
|
|
return -EBUSY;
|
|
|
|
/* we call try-to-free pages for make this cgroup empty */
|
|
lru_add_drain_all();
|
|
/* try to free all pages in this cgroup */
|
|
while (nr_retries && res_counter_read_u64(&memcg->res, RES_USAGE) > 0) {
|
|
int progress;
|
|
|
|
if (signal_pending(current))
|
|
return -EINTR;
|
|
|
|
progress = try_to_free_mem_cgroup_pages(memcg, GFP_KERNEL,
|
|
false);
|
|
if (!progress) {
|
|
nr_retries--;
|
|
/* maybe some writeback is necessary */
|
|
congestion_wait(BLK_RW_ASYNC, HZ/10);
|
|
}
|
|
|
|
}
|
|
lru_add_drain();
|
|
mem_cgroup_reparent_charges(memcg);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int mem_cgroup_force_empty_write(struct cgroup_subsys_state *css,
|
|
unsigned int event)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
|
|
if (mem_cgroup_is_root(memcg))
|
|
return -EINVAL;
|
|
return mem_cgroup_force_empty(memcg);
|
|
}
|
|
|
|
static u64 mem_cgroup_hierarchy_read(struct cgroup_subsys_state *css,
|
|
struct cftype *cft)
|
|
{
|
|
return mem_cgroup_from_css(css)->use_hierarchy;
|
|
}
|
|
|
|
static int mem_cgroup_hierarchy_write(struct cgroup_subsys_state *css,
|
|
struct cftype *cft, u64 val)
|
|
{
|
|
int retval = 0;
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
struct mem_cgroup *parent_memcg = mem_cgroup_from_css(css_parent(&memcg->css));
|
|
|
|
mutex_lock(&memcg_create_mutex);
|
|
|
|
if (memcg->use_hierarchy == val)
|
|
goto out;
|
|
|
|
/*
|
|
* If parent's use_hierarchy is set, we can't make any modifications
|
|
* in the child subtrees. If it is unset, then the change can
|
|
* occur, provided the current cgroup has no children.
|
|
*
|
|
* For the root cgroup, parent_mem is NULL, we allow value to be
|
|
* set if there are no children.
|
|
*/
|
|
if ((!parent_memcg || !parent_memcg->use_hierarchy) &&
|
|
(val == 1 || val == 0)) {
|
|
if (list_empty(&memcg->css.cgroup->children))
|
|
memcg->use_hierarchy = val;
|
|
else
|
|
retval = -EBUSY;
|
|
} else
|
|
retval = -EINVAL;
|
|
|
|
out:
|
|
mutex_unlock(&memcg_create_mutex);
|
|
|
|
return retval;
|
|
}
|
|
|
|
|
|
static unsigned long mem_cgroup_recursive_stat(struct mem_cgroup *memcg,
|
|
enum mem_cgroup_stat_index idx)
|
|
{
|
|
struct mem_cgroup *iter;
|
|
long val = 0;
|
|
|
|
/* Per-cpu values can be negative, use a signed accumulator */
|
|
for_each_mem_cgroup_tree(iter, memcg)
|
|
val += mem_cgroup_read_stat(iter, idx);
|
|
|
|
if (val < 0) /* race ? */
|
|
val = 0;
|
|
return val;
|
|
}
|
|
|
|
static inline u64 mem_cgroup_usage(struct mem_cgroup *memcg, bool swap)
|
|
{
|
|
u64 val;
|
|
|
|
if (!mem_cgroup_is_root(memcg)) {
|
|
if (!swap)
|
|
return res_counter_read_u64(&memcg->res, RES_USAGE);
|
|
else
|
|
return res_counter_read_u64(&memcg->memsw, RES_USAGE);
|
|
}
|
|
|
|
/*
|
|
* Transparent hugepages are still accounted for in MEM_CGROUP_STAT_RSS
|
|
* as well as in MEM_CGROUP_STAT_RSS_HUGE.
|
|
*/
|
|
val = mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_CACHE);
|
|
val += mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_RSS);
|
|
|
|
if (swap)
|
|
val += mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_SWAP);
|
|
|
|
return val << PAGE_SHIFT;
|
|
}
|
|
|
|
static ssize_t mem_cgroup_read(struct cgroup_subsys_state *css,
|
|
struct cftype *cft, struct file *file,
|
|
char __user *buf, size_t nbytes, loff_t *ppos)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
char str[64];
|
|
u64 val;
|
|
int name, len;
|
|
enum res_type type;
|
|
|
|
type = MEMFILE_TYPE(cft->private);
|
|
name = MEMFILE_ATTR(cft->private);
|
|
|
|
switch (type) {
|
|
case _MEM:
|
|
if (name == RES_USAGE)
|
|
val = mem_cgroup_usage(memcg, false);
|
|
else
|
|
val = res_counter_read_u64(&memcg->res, name);
|
|
break;
|
|
case _MEMSWAP:
|
|
if (name == RES_USAGE)
|
|
val = mem_cgroup_usage(memcg, true);
|
|
else
|
|
val = res_counter_read_u64(&memcg->memsw, name);
|
|
break;
|
|
case _KMEM:
|
|
val = res_counter_read_u64(&memcg->kmem, name);
|
|
break;
|
|
default:
|
|
BUG();
|
|
}
|
|
|
|
len = scnprintf(str, sizeof(str), "%llu\n", (unsigned long long)val);
|
|
return simple_read_from_buffer(buf, nbytes, ppos, str, len);
|
|
}
|
|
|
|
static int memcg_update_kmem_limit(struct cgroup_subsys_state *css, u64 val)
|
|
{
|
|
int ret = -EINVAL;
|
|
#ifdef CONFIG_MEMCG_KMEM
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
/*
|
|
* For simplicity, we won't allow this to be disabled. It also can't
|
|
* be changed if the cgroup has children already, or if tasks had
|
|
* already joined.
|
|
*
|
|
* If tasks join before we set the limit, a person looking at
|
|
* kmem.usage_in_bytes will have no way to determine when it took
|
|
* place, which makes the value quite meaningless.
|
|
*
|
|
* After it first became limited, changes in the value of the limit are
|
|
* of course permitted.
|
|
*/
|
|
mutex_lock(&memcg_create_mutex);
|
|
mutex_lock(&set_limit_mutex);
|
|
if (!memcg->kmem_account_flags && val != RES_COUNTER_MAX) {
|
|
if (cgroup_task_count(css->cgroup) || memcg_has_children(memcg)) {
|
|
ret = -EBUSY;
|
|
goto out;
|
|
}
|
|
ret = res_counter_set_limit(&memcg->kmem, val);
|
|
VM_BUG_ON(ret);
|
|
|
|
ret = memcg_update_cache_sizes(memcg);
|
|
if (ret) {
|
|
res_counter_set_limit(&memcg->kmem, RES_COUNTER_MAX);
|
|
goto out;
|
|
}
|
|
static_key_slow_inc(&memcg_kmem_enabled_key);
|
|
/*
|
|
* setting the active bit after the inc will guarantee no one
|
|
* starts accounting before all call sites are patched
|
|
*/
|
|
memcg_kmem_set_active(memcg);
|
|
} else
|
|
ret = res_counter_set_limit(&memcg->kmem, val);
|
|
out:
|
|
mutex_unlock(&set_limit_mutex);
|
|
mutex_unlock(&memcg_create_mutex);
|
|
#endif
|
|
return ret;
|
|
}
|
|
|
|
#ifdef CONFIG_MEMCG_KMEM
|
|
static int memcg_propagate_kmem(struct mem_cgroup *memcg)
|
|
{
|
|
int ret = 0;
|
|
struct mem_cgroup *parent = parent_mem_cgroup(memcg);
|
|
if (!parent)
|
|
goto out;
|
|
|
|
memcg->kmem_account_flags = parent->kmem_account_flags;
|
|
/*
|
|
* When that happen, we need to disable the static branch only on those
|
|
* memcgs that enabled it. To achieve this, we would be forced to
|
|
* complicate the code by keeping track of which memcgs were the ones
|
|
* that actually enabled limits, and which ones got it from its
|
|
* parents.
|
|
*
|
|
* It is a lot simpler just to do static_key_slow_inc() on every child
|
|
* that is accounted.
|
|
*/
|
|
if (!memcg_kmem_is_active(memcg))
|
|
goto out;
|
|
|
|
/*
|
|
* __mem_cgroup_free() will issue static_key_slow_dec() because this
|
|
* memcg is active already. If the later initialization fails then the
|
|
* cgroup core triggers the cleanup so we do not have to do it here.
|
|
*/
|
|
static_key_slow_inc(&memcg_kmem_enabled_key);
|
|
|
|
mutex_lock(&set_limit_mutex);
|
|
memcg_stop_kmem_account();
|
|
ret = memcg_update_cache_sizes(memcg);
|
|
memcg_resume_kmem_account();
|
|
mutex_unlock(&set_limit_mutex);
|
|
out:
|
|
return ret;
|
|
}
|
|
#endif /* CONFIG_MEMCG_KMEM */
|
|
|
|
/*
|
|
* The user of this function is...
|
|
* RES_LIMIT.
|
|
*/
|
|
static int mem_cgroup_write(struct cgroup_subsys_state *css, struct cftype *cft,
|
|
const char *buffer)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
enum res_type type;
|
|
int name;
|
|
unsigned long long val;
|
|
int ret;
|
|
|
|
type = MEMFILE_TYPE(cft->private);
|
|
name = MEMFILE_ATTR(cft->private);
|
|
|
|
switch (name) {
|
|
case RES_LIMIT:
|
|
if (mem_cgroup_is_root(memcg)) { /* Can't set limit on root */
|
|
ret = -EINVAL;
|
|
break;
|
|
}
|
|
/* This function does all necessary parse...reuse it */
|
|
ret = res_counter_memparse_write_strategy(buffer, &val);
|
|
if (ret)
|
|
break;
|
|
if (type == _MEM)
|
|
ret = mem_cgroup_resize_limit(memcg, val);
|
|
else if (type == _MEMSWAP)
|
|
ret = mem_cgroup_resize_memsw_limit(memcg, val);
|
|
else if (type == _KMEM)
|
|
ret = memcg_update_kmem_limit(css, val);
|
|
else
|
|
return -EINVAL;
|
|
break;
|
|
case RES_SOFT_LIMIT:
|
|
ret = res_counter_memparse_write_strategy(buffer, &val);
|
|
if (ret)
|
|
break;
|
|
/*
|
|
* For memsw, soft limits are hard to implement in terms
|
|
* of semantics, for now, we support soft limits for
|
|
* control without swap
|
|
*/
|
|
if (type == _MEM)
|
|
ret = res_counter_set_soft_limit(&memcg->res, val);
|
|
else
|
|
ret = -EINVAL;
|
|
break;
|
|
default:
|
|
ret = -EINVAL; /* should be BUG() ? */
|
|
break;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg,
|
|
unsigned long long *mem_limit, unsigned long long *memsw_limit)
|
|
{
|
|
unsigned long long min_limit, min_memsw_limit, tmp;
|
|
|
|
min_limit = res_counter_read_u64(&memcg->res, RES_LIMIT);
|
|
min_memsw_limit = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
|
|
if (!memcg->use_hierarchy)
|
|
goto out;
|
|
|
|
while (css_parent(&memcg->css)) {
|
|
memcg = mem_cgroup_from_css(css_parent(&memcg->css));
|
|
if (!memcg->use_hierarchy)
|
|
break;
|
|
tmp = res_counter_read_u64(&memcg->res, RES_LIMIT);
|
|
min_limit = min(min_limit, tmp);
|
|
tmp = res_counter_read_u64(&memcg->memsw, RES_LIMIT);
|
|
min_memsw_limit = min(min_memsw_limit, tmp);
|
|
}
|
|
out:
|
|
*mem_limit = min_limit;
|
|
*memsw_limit = min_memsw_limit;
|
|
}
|
|
|
|
static int mem_cgroup_reset(struct cgroup_subsys_state *css, unsigned int event)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
int name;
|
|
enum res_type type;
|
|
|
|
type = MEMFILE_TYPE(event);
|
|
name = MEMFILE_ATTR(event);
|
|
|
|
switch (name) {
|
|
case RES_MAX_USAGE:
|
|
if (type == _MEM)
|
|
res_counter_reset_max(&memcg->res);
|
|
else if (type == _MEMSWAP)
|
|
res_counter_reset_max(&memcg->memsw);
|
|
else if (type == _KMEM)
|
|
res_counter_reset_max(&memcg->kmem);
|
|
else
|
|
return -EINVAL;
|
|
break;
|
|
case RES_FAILCNT:
|
|
if (type == _MEM)
|
|
res_counter_reset_failcnt(&memcg->res);
|
|
else if (type == _MEMSWAP)
|
|
res_counter_reset_failcnt(&memcg->memsw);
|
|
else if (type == _KMEM)
|
|
res_counter_reset_failcnt(&memcg->kmem);
|
|
else
|
|
return -EINVAL;
|
|
break;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static u64 mem_cgroup_move_charge_read(struct cgroup_subsys_state *css,
|
|
struct cftype *cft)
|
|
{
|
|
return mem_cgroup_from_css(css)->move_charge_at_immigrate;
|
|
}
|
|
|
|
#ifdef CONFIG_MMU
|
|
static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css,
|
|
struct cftype *cft, u64 val)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
|
|
if (val >= (1 << NR_MOVE_TYPE))
|
|
return -EINVAL;
|
|
|
|
/*
|
|
* No kind of locking is needed in here, because ->can_attach() will
|
|
* check this value once in the beginning of the process, and then carry
|
|
* on with stale data. This means that changes to this value will only
|
|
* affect task migrations starting after the change.
|
|
*/
|
|
memcg->move_charge_at_immigrate = val;
|
|
return 0;
|
|
}
|
|
#else
|
|
static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css,
|
|
struct cftype *cft, u64 val)
|
|
{
|
|
return -ENOSYS;
|
|
}
|
|
#endif
|
|
|
|
#ifdef CONFIG_NUMA
|
|
static int memcg_numa_stat_show(struct cgroup_subsys_state *css,
|
|
struct cftype *cft, struct seq_file *m)
|
|
{
|
|
int nid;
|
|
unsigned long total_nr, file_nr, anon_nr, unevictable_nr;
|
|
unsigned long node_nr;
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
|
|
total_nr = mem_cgroup_nr_lru_pages(memcg, LRU_ALL);
|
|
seq_printf(m, "total=%lu", total_nr);
|
|
for_each_node_state(nid, N_MEMORY) {
|
|
node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid, LRU_ALL);
|
|
seq_printf(m, " N%d=%lu", nid, node_nr);
|
|
}
|
|
seq_putc(m, '\n');
|
|
|
|
file_nr = mem_cgroup_nr_lru_pages(memcg, LRU_ALL_FILE);
|
|
seq_printf(m, "file=%lu", file_nr);
|
|
for_each_node_state(nid, N_MEMORY) {
|
|
node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid,
|
|
LRU_ALL_FILE);
|
|
seq_printf(m, " N%d=%lu", nid, node_nr);
|
|
}
|
|
seq_putc(m, '\n');
|
|
|
|
anon_nr = mem_cgroup_nr_lru_pages(memcg, LRU_ALL_ANON);
|
|
seq_printf(m, "anon=%lu", anon_nr);
|
|
for_each_node_state(nid, N_MEMORY) {
|
|
node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid,
|
|
LRU_ALL_ANON);
|
|
seq_printf(m, " N%d=%lu", nid, node_nr);
|
|
}
|
|
seq_putc(m, '\n');
|
|
|
|
unevictable_nr = mem_cgroup_nr_lru_pages(memcg, BIT(LRU_UNEVICTABLE));
|
|
seq_printf(m, "unevictable=%lu", unevictable_nr);
|
|
for_each_node_state(nid, N_MEMORY) {
|
|
node_nr = mem_cgroup_node_nr_lru_pages(memcg, nid,
|
|
BIT(LRU_UNEVICTABLE));
|
|
seq_printf(m, " N%d=%lu", nid, node_nr);
|
|
}
|
|
seq_putc(m, '\n');
|
|
return 0;
|
|
}
|
|
#endif /* CONFIG_NUMA */
|
|
|
|
static inline void mem_cgroup_lru_names_not_uptodate(void)
|
|
{
|
|
BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names) != NR_LRU_LISTS);
|
|
}
|
|
|
|
static int memcg_stat_show(struct cgroup_subsys_state *css, struct cftype *cft,
|
|
struct seq_file *m)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
struct mem_cgroup *mi;
|
|
unsigned int i;
|
|
|
|
for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) {
|
|
if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account)
|
|
continue;
|
|
seq_printf(m, "%s %ld\n", mem_cgroup_stat_names[i],
|
|
mem_cgroup_read_stat(memcg, i) * PAGE_SIZE);
|
|
}
|
|
|
|
for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++)
|
|
seq_printf(m, "%s %lu\n", mem_cgroup_events_names[i],
|
|
mem_cgroup_read_events(memcg, i));
|
|
|
|
for (i = 0; i < NR_LRU_LISTS; i++)
|
|
seq_printf(m, "%s %lu\n", mem_cgroup_lru_names[i],
|
|
mem_cgroup_nr_lru_pages(memcg, BIT(i)) * PAGE_SIZE);
|
|
|
|
/* Hierarchical information */
|
|
{
|
|
unsigned long long limit, memsw_limit;
|
|
memcg_get_hierarchical_limit(memcg, &limit, &memsw_limit);
|
|
seq_printf(m, "hierarchical_memory_limit %llu\n", limit);
|
|
if (do_swap_account)
|
|
seq_printf(m, "hierarchical_memsw_limit %llu\n",
|
|
memsw_limit);
|
|
}
|
|
|
|
for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) {
|
|
long long val = 0;
|
|
|
|
if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account)
|
|
continue;
|
|
for_each_mem_cgroup_tree(mi, memcg)
|
|
val += mem_cgroup_read_stat(mi, i) * PAGE_SIZE;
|
|
seq_printf(m, "total_%s %lld\n", mem_cgroup_stat_names[i], val);
|
|
}
|
|
|
|
for (i = 0; i < MEM_CGROUP_EVENTS_NSTATS; i++) {
|
|
unsigned long long val = 0;
|
|
|
|
for_each_mem_cgroup_tree(mi, memcg)
|
|
val += mem_cgroup_read_events(mi, i);
|
|
seq_printf(m, "total_%s %llu\n",
|
|
mem_cgroup_events_names[i], val);
|
|
}
|
|
|
|
for (i = 0; i < NR_LRU_LISTS; i++) {
|
|
unsigned long long val = 0;
|
|
|
|
for_each_mem_cgroup_tree(mi, memcg)
|
|
val += mem_cgroup_nr_lru_pages(mi, BIT(i)) * PAGE_SIZE;
|
|
seq_printf(m, "total_%s %llu\n", mem_cgroup_lru_names[i], val);
|
|
}
|
|
|
|
#ifdef CONFIG_DEBUG_VM
|
|
{
|
|
int nid, zid;
|
|
struct mem_cgroup_per_zone *mz;
|
|
struct zone_reclaim_stat *rstat;
|
|
unsigned long recent_rotated[2] = {0, 0};
|
|
unsigned long recent_scanned[2] = {0, 0};
|
|
|
|
for_each_online_node(nid)
|
|
for (zid = 0; zid < MAX_NR_ZONES; zid++) {
|
|
mz = mem_cgroup_zoneinfo(memcg, nid, zid);
|
|
rstat = &mz->lruvec.reclaim_stat;
|
|
|
|
recent_rotated[0] += rstat->recent_rotated[0];
|
|
recent_rotated[1] += rstat->recent_rotated[1];
|
|
recent_scanned[0] += rstat->recent_scanned[0];
|
|
recent_scanned[1] += rstat->recent_scanned[1];
|
|
}
|
|
seq_printf(m, "recent_rotated_anon %lu\n", recent_rotated[0]);
|
|
seq_printf(m, "recent_rotated_file %lu\n", recent_rotated[1]);
|
|
seq_printf(m, "recent_scanned_anon %lu\n", recent_scanned[0]);
|
|
seq_printf(m, "recent_scanned_file %lu\n", recent_scanned[1]);
|
|
}
|
|
#endif
|
|
|
|
return 0;
|
|
}
|
|
|
|
static u64 mem_cgroup_swappiness_read(struct cgroup_subsys_state *css,
|
|
struct cftype *cft)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
|
|
return mem_cgroup_swappiness(memcg);
|
|
}
|
|
|
|
static int mem_cgroup_swappiness_write(struct cgroup_subsys_state *css,
|
|
struct cftype *cft, u64 val)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
struct mem_cgroup *parent = mem_cgroup_from_css(css_parent(&memcg->css));
|
|
|
|
if (val > 100 || !parent)
|
|
return -EINVAL;
|
|
|
|
mutex_lock(&memcg_create_mutex);
|
|
|
|
/* If under hierarchy, only empty-root can set this value */
|
|
if ((parent->use_hierarchy) || memcg_has_children(memcg)) {
|
|
mutex_unlock(&memcg_create_mutex);
|
|
return -EINVAL;
|
|
}
|
|
|
|
memcg->swappiness = val;
|
|
|
|
mutex_unlock(&memcg_create_mutex);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void __mem_cgroup_threshold(struct mem_cgroup *memcg, bool swap)
|
|
{
|
|
struct mem_cgroup_threshold_ary *t;
|
|
u64 usage;
|
|
int i;
|
|
|
|
rcu_read_lock();
|
|
if (!swap)
|
|
t = rcu_dereference(memcg->thresholds.primary);
|
|
else
|
|
t = rcu_dereference(memcg->memsw_thresholds.primary);
|
|
|
|
if (!t)
|
|
goto unlock;
|
|
|
|
usage = mem_cgroup_usage(memcg, swap);
|
|
|
|
/*
|
|
* current_threshold points to threshold just below or equal to usage.
|
|
* If it's not true, a threshold was crossed after last
|
|
* call of __mem_cgroup_threshold().
|
|
*/
|
|
i = t->current_threshold;
|
|
|
|
/*
|
|
* Iterate backward over array of thresholds starting from
|
|
* current_threshold and check if a threshold is crossed.
|
|
* If none of thresholds below usage is crossed, we read
|
|
* only one element of the array here.
|
|
*/
|
|
for (; i >= 0 && unlikely(t->entries[i].threshold > usage); i--)
|
|
eventfd_signal(t->entries[i].eventfd, 1);
|
|
|
|
/* i = current_threshold + 1 */
|
|
i++;
|
|
|
|
/*
|
|
* Iterate forward over array of thresholds starting from
|
|
* current_threshold+1 and check if a threshold is crossed.
|
|
* If none of thresholds above usage is crossed, we read
|
|
* only one element of the array here.
|
|
*/
|
|
for (; i < t->size && unlikely(t->entries[i].threshold <= usage); i++)
|
|
eventfd_signal(t->entries[i].eventfd, 1);
|
|
|
|
/* Update current_threshold */
|
|
t->current_threshold = i - 1;
|
|
unlock:
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
static void mem_cgroup_threshold(struct mem_cgroup *memcg)
|
|
{
|
|
while (memcg) {
|
|
__mem_cgroup_threshold(memcg, false);
|
|
if (do_swap_account)
|
|
__mem_cgroup_threshold(memcg, true);
|
|
|
|
memcg = parent_mem_cgroup(memcg);
|
|
}
|
|
}
|
|
|
|
static int compare_thresholds(const void *a, const void *b)
|
|
{
|
|
const struct mem_cgroup_threshold *_a = a;
|
|
const struct mem_cgroup_threshold *_b = b;
|
|
|
|
if (_a->threshold > _b->threshold)
|
|
return 1;
|
|
|
|
if (_a->threshold < _b->threshold)
|
|
return -1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int mem_cgroup_oom_notify_cb(struct mem_cgroup *memcg)
|
|
{
|
|
struct mem_cgroup_eventfd_list *ev;
|
|
|
|
list_for_each_entry(ev, &memcg->oom_notify, list)
|
|
eventfd_signal(ev->eventfd, 1);
|
|
return 0;
|
|
}
|
|
|
|
static void mem_cgroup_oom_notify(struct mem_cgroup *memcg)
|
|
{
|
|
struct mem_cgroup *iter;
|
|
|
|
for_each_mem_cgroup_tree(iter, memcg)
|
|
mem_cgroup_oom_notify_cb(iter);
|
|
}
|
|
|
|
static int mem_cgroup_usage_register_event(struct cgroup_subsys_state *css,
|
|
struct cftype *cft, struct eventfd_ctx *eventfd, const char *args)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
struct mem_cgroup_thresholds *thresholds;
|
|
struct mem_cgroup_threshold_ary *new;
|
|
enum res_type type = MEMFILE_TYPE(cft->private);
|
|
u64 threshold, usage;
|
|
int i, size, ret;
|
|
|
|
ret = res_counter_memparse_write_strategy(args, &threshold);
|
|
if (ret)
|
|
return ret;
|
|
|
|
mutex_lock(&memcg->thresholds_lock);
|
|
|
|
if (type == _MEM)
|
|
thresholds = &memcg->thresholds;
|
|
else if (type == _MEMSWAP)
|
|
thresholds = &memcg->memsw_thresholds;
|
|
else
|
|
BUG();
|
|
|
|
usage = mem_cgroup_usage(memcg, type == _MEMSWAP);
|
|
|
|
/* Check if a threshold crossed before adding a new one */
|
|
if (thresholds->primary)
|
|
__mem_cgroup_threshold(memcg, type == _MEMSWAP);
|
|
|
|
size = thresholds->primary ? thresholds->primary->size + 1 : 1;
|
|
|
|
/* Allocate memory for new array of thresholds */
|
|
new = kmalloc(sizeof(*new) + size * sizeof(struct mem_cgroup_threshold),
|
|
GFP_KERNEL);
|
|
if (!new) {
|
|
ret = -ENOMEM;
|
|
goto unlock;
|
|
}
|
|
new->size = size;
|
|
|
|
/* Copy thresholds (if any) to new array */
|
|
if (thresholds->primary) {
|
|
memcpy(new->entries, thresholds->primary->entries, (size - 1) *
|
|
sizeof(struct mem_cgroup_threshold));
|
|
}
|
|
|
|
/* Add new threshold */
|
|
new->entries[size - 1].eventfd = eventfd;
|
|
new->entries[size - 1].threshold = threshold;
|
|
|
|
/* Sort thresholds. Registering of new threshold isn't time-critical */
|
|
sort(new->entries, size, sizeof(struct mem_cgroup_threshold),
|
|
compare_thresholds, NULL);
|
|
|
|
/* Find current threshold */
|
|
new->current_threshold = -1;
|
|
for (i = 0; i < size; i++) {
|
|
if (new->entries[i].threshold <= usage) {
|
|
/*
|
|
* new->current_threshold will not be used until
|
|
* rcu_assign_pointer(), so it's safe to increment
|
|
* it here.
|
|
*/
|
|
++new->current_threshold;
|
|
} else
|
|
break;
|
|
}
|
|
|
|
/* Free old spare buffer and save old primary buffer as spare */
|
|
kfree(thresholds->spare);
|
|
thresholds->spare = thresholds->primary;
|
|
|
|
rcu_assign_pointer(thresholds->primary, new);
|
|
|
|
/* To be sure that nobody uses thresholds */
|
|
synchronize_rcu();
|
|
|
|
unlock:
|
|
mutex_unlock(&memcg->thresholds_lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void mem_cgroup_usage_unregister_event(struct cgroup_subsys_state *css,
|
|
struct cftype *cft, struct eventfd_ctx *eventfd)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
struct mem_cgroup_thresholds *thresholds;
|
|
struct mem_cgroup_threshold_ary *new;
|
|
enum res_type type = MEMFILE_TYPE(cft->private);
|
|
u64 usage;
|
|
int i, j, size;
|
|
|
|
mutex_lock(&memcg->thresholds_lock);
|
|
if (type == _MEM)
|
|
thresholds = &memcg->thresholds;
|
|
else if (type == _MEMSWAP)
|
|
thresholds = &memcg->memsw_thresholds;
|
|
else
|
|
BUG();
|
|
|
|
if (!thresholds->primary)
|
|
goto unlock;
|
|
|
|
usage = mem_cgroup_usage(memcg, type == _MEMSWAP);
|
|
|
|
/* Check if a threshold crossed before removing */
|
|
__mem_cgroup_threshold(memcg, type == _MEMSWAP);
|
|
|
|
/* Calculate new number of threshold */
|
|
size = 0;
|
|
for (i = 0; i < thresholds->primary->size; i++) {
|
|
if (thresholds->primary->entries[i].eventfd != eventfd)
|
|
size++;
|
|
}
|
|
|
|
new = thresholds->spare;
|
|
|
|
/* Set thresholds array to NULL if we don't have thresholds */
|
|
if (!size) {
|
|
kfree(new);
|
|
new = NULL;
|
|
goto swap_buffers;
|
|
}
|
|
|
|
new->size = size;
|
|
|
|
/* Copy thresholds and find current threshold */
|
|
new->current_threshold = -1;
|
|
for (i = 0, j = 0; i < thresholds->primary->size; i++) {
|
|
if (thresholds->primary->entries[i].eventfd == eventfd)
|
|
continue;
|
|
|
|
new->entries[j] = thresholds->primary->entries[i];
|
|
if (new->entries[j].threshold <= usage) {
|
|
/*
|
|
* new->current_threshold will not be used
|
|
* until rcu_assign_pointer(), so it's safe to increment
|
|
* it here.
|
|
*/
|
|
++new->current_threshold;
|
|
}
|
|
j++;
|
|
}
|
|
|
|
swap_buffers:
|
|
/* Swap primary and spare array */
|
|
thresholds->spare = thresholds->primary;
|
|
/* If all events are unregistered, free the spare array */
|
|
if (!new) {
|
|
kfree(thresholds->spare);
|
|
thresholds->spare = NULL;
|
|
}
|
|
|
|
rcu_assign_pointer(thresholds->primary, new);
|
|
|
|
/* To be sure that nobody uses thresholds */
|
|
synchronize_rcu();
|
|
unlock:
|
|
mutex_unlock(&memcg->thresholds_lock);
|
|
}
|
|
|
|
static int mem_cgroup_oom_register_event(struct cgroup_subsys_state *css,
|
|
struct cftype *cft, struct eventfd_ctx *eventfd, const char *args)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
struct mem_cgroup_eventfd_list *event;
|
|
enum res_type type = MEMFILE_TYPE(cft->private);
|
|
|
|
BUG_ON(type != _OOM_TYPE);
|
|
event = kmalloc(sizeof(*event), GFP_KERNEL);
|
|
if (!event)
|
|
return -ENOMEM;
|
|
|
|
spin_lock(&memcg_oom_lock);
|
|
|
|
event->eventfd = eventfd;
|
|
list_add(&event->list, &memcg->oom_notify);
|
|
|
|
/* already in OOM ? */
|
|
if (atomic_read(&memcg->under_oom))
|
|
eventfd_signal(eventfd, 1);
|
|
spin_unlock(&memcg_oom_lock);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void mem_cgroup_oom_unregister_event(struct cgroup_subsys_state *css,
|
|
struct cftype *cft, struct eventfd_ctx *eventfd)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
struct mem_cgroup_eventfd_list *ev, *tmp;
|
|
enum res_type type = MEMFILE_TYPE(cft->private);
|
|
|
|
BUG_ON(type != _OOM_TYPE);
|
|
|
|
spin_lock(&memcg_oom_lock);
|
|
|
|
list_for_each_entry_safe(ev, tmp, &memcg->oom_notify, list) {
|
|
if (ev->eventfd == eventfd) {
|
|
list_del(&ev->list);
|
|
kfree(ev);
|
|
}
|
|
}
|
|
|
|
spin_unlock(&memcg_oom_lock);
|
|
}
|
|
|
|
static int mem_cgroup_oom_control_read(struct cgroup_subsys_state *css,
|
|
struct cftype *cft, struct cgroup_map_cb *cb)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
|
|
cb->fill(cb, "oom_kill_disable", memcg->oom_kill_disable);
|
|
|
|
if (atomic_read(&memcg->under_oom))
|
|
cb->fill(cb, "under_oom", 1);
|
|
else
|
|
cb->fill(cb, "under_oom", 0);
|
|
return 0;
|
|
}
|
|
|
|
static int mem_cgroup_oom_control_write(struct cgroup_subsys_state *css,
|
|
struct cftype *cft, u64 val)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
struct mem_cgroup *parent = mem_cgroup_from_css(css_parent(&memcg->css));
|
|
|
|
/* cannot set to root cgroup and only 0 and 1 are allowed */
|
|
if (!parent || !((val == 0) || (val == 1)))
|
|
return -EINVAL;
|
|
|
|
mutex_lock(&memcg_create_mutex);
|
|
/* oom-kill-disable is a flag for subhierarchy. */
|
|
if ((parent->use_hierarchy) || memcg_has_children(memcg)) {
|
|
mutex_unlock(&memcg_create_mutex);
|
|
return -EINVAL;
|
|
}
|
|
memcg->oom_kill_disable = val;
|
|
if (!val)
|
|
memcg_oom_recover(memcg);
|
|
mutex_unlock(&memcg_create_mutex);
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_MEMCG_KMEM
|
|
static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
|
|
{
|
|
int ret;
|
|
|
|
memcg->kmemcg_id = -1;
|
|
ret = memcg_propagate_kmem(memcg);
|
|
if (ret)
|
|
return ret;
|
|
|
|
return mem_cgroup_sockets_init(memcg, ss);
|
|
}
|
|
|
|
static void memcg_destroy_kmem(struct mem_cgroup *memcg)
|
|
{
|
|
mem_cgroup_sockets_destroy(memcg);
|
|
}
|
|
|
|
static void kmem_cgroup_css_offline(struct mem_cgroup *memcg)
|
|
{
|
|
if (!memcg_kmem_is_active(memcg))
|
|
return;
|
|
|
|
/*
|
|
* kmem charges can outlive the cgroup. In the case of slab
|
|
* pages, for instance, a page contain objects from various
|
|
* processes. As we prevent from taking a reference for every
|
|
* such allocation we have to be careful when doing uncharge
|
|
* (see memcg_uncharge_kmem) and here during offlining.
|
|
*
|
|
* The idea is that that only the _last_ uncharge which sees
|
|
* the dead memcg will drop the last reference. An additional
|
|
* reference is taken here before the group is marked dead
|
|
* which is then paired with css_put during uncharge resp. here.
|
|
*
|
|
* Although this might sound strange as this path is called from
|
|
* css_offline() when the referencemight have dropped down to 0
|
|
* and shouldn't be incremented anymore (css_tryget would fail)
|
|
* we do not have other options because of the kmem allocations
|
|
* lifetime.
|
|
*/
|
|
css_get(&memcg->css);
|
|
|
|
memcg_kmem_mark_dead(memcg);
|
|
|
|
if (res_counter_read_u64(&memcg->kmem, RES_USAGE) != 0)
|
|
return;
|
|
|
|
if (memcg_kmem_test_and_clear_dead(memcg))
|
|
css_put(&memcg->css);
|
|
}
|
|
#else
|
|
static int memcg_init_kmem(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static void memcg_destroy_kmem(struct mem_cgroup *memcg)
|
|
{
|
|
}
|
|
|
|
static void kmem_cgroup_css_offline(struct mem_cgroup *memcg)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* Unregister event and free resources.
|
|
*
|
|
* Gets called from workqueue.
|
|
*/
|
|
static void cgroup_event_remove(struct work_struct *work)
|
|
{
|
|
struct cgroup_event *event = container_of(work, struct cgroup_event,
|
|
remove);
|
|
struct cgroup_subsys_state *css = event->css;
|
|
|
|
remove_wait_queue(event->wqh, &event->wait);
|
|
|
|
event->cft->unregister_event(css, event->cft, event->eventfd);
|
|
|
|
/* Notify userspace the event is going away. */
|
|
eventfd_signal(event->eventfd, 1);
|
|
|
|
eventfd_ctx_put(event->eventfd);
|
|
kfree(event);
|
|
css_put(css);
|
|
}
|
|
|
|
/*
|
|
* Gets called on POLLHUP on eventfd when user closes it.
|
|
*
|
|
* Called with wqh->lock held and interrupts disabled.
|
|
*/
|
|
static int cgroup_event_wake(wait_queue_t *wait, unsigned mode,
|
|
int sync, void *key)
|
|
{
|
|
struct cgroup_event *event = container_of(wait,
|
|
struct cgroup_event, wait);
|
|
struct cgroup *cgrp = event->css->cgroup;
|
|
unsigned long flags = (unsigned long)key;
|
|
|
|
if (flags & POLLHUP) {
|
|
/*
|
|
* If the event has been detached at cgroup removal, we
|
|
* can simply return knowing the other side will cleanup
|
|
* for us.
|
|
*
|
|
* We can't race against event freeing since the other
|
|
* side will require wqh->lock via remove_wait_queue(),
|
|
* which we hold.
|
|
*/
|
|
spin_lock(&cgrp->event_list_lock);
|
|
if (!list_empty(&event->list)) {
|
|
list_del_init(&event->list);
|
|
/*
|
|
* We are in atomic context, but cgroup_event_remove()
|
|
* may sleep, so we have to call it in workqueue.
|
|
*/
|
|
schedule_work(&event->remove);
|
|
}
|
|
spin_unlock(&cgrp->event_list_lock);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void cgroup_event_ptable_queue_proc(struct file *file,
|
|
wait_queue_head_t *wqh, poll_table *pt)
|
|
{
|
|
struct cgroup_event *event = container_of(pt,
|
|
struct cgroup_event, pt);
|
|
|
|
event->wqh = wqh;
|
|
add_wait_queue(wqh, &event->wait);
|
|
}
|
|
|
|
/*
|
|
* Parse input and register new cgroup event handler.
|
|
*
|
|
* Input must be in format '<event_fd> <control_fd> <args>'.
|
|
* Interpretation of args is defined by control file implementation.
|
|
*/
|
|
static int cgroup_write_event_control(struct cgroup_subsys_state *dummy_css,
|
|
struct cftype *cft, const char *buffer)
|
|
{
|
|
struct cgroup *cgrp = dummy_css->cgroup;
|
|
struct cgroup_event *event;
|
|
struct cgroup_subsys_state *cfile_css;
|
|
unsigned int efd, cfd;
|
|
struct fd efile;
|
|
struct fd cfile;
|
|
char *endp;
|
|
int ret;
|
|
|
|
efd = simple_strtoul(buffer, &endp, 10);
|
|
if (*endp != ' ')
|
|
return -EINVAL;
|
|
buffer = endp + 1;
|
|
|
|
cfd = simple_strtoul(buffer, &endp, 10);
|
|
if ((*endp != ' ') && (*endp != '\0'))
|
|
return -EINVAL;
|
|
buffer = endp + 1;
|
|
|
|
event = kzalloc(sizeof(*event), GFP_KERNEL);
|
|
if (!event)
|
|
return -ENOMEM;
|
|
|
|
INIT_LIST_HEAD(&event->list);
|
|
init_poll_funcptr(&event->pt, cgroup_event_ptable_queue_proc);
|
|
init_waitqueue_func_entry(&event->wait, cgroup_event_wake);
|
|
INIT_WORK(&event->remove, cgroup_event_remove);
|
|
|
|
efile = fdget(efd);
|
|
if (!efile.file) {
|
|
ret = -EBADF;
|
|
goto out_kfree;
|
|
}
|
|
|
|
event->eventfd = eventfd_ctx_fileget(efile.file);
|
|
if (IS_ERR(event->eventfd)) {
|
|
ret = PTR_ERR(event->eventfd);
|
|
goto out_put_efile;
|
|
}
|
|
|
|
cfile = fdget(cfd);
|
|
if (!cfile.file) {
|
|
ret = -EBADF;
|
|
goto out_put_eventfd;
|
|
}
|
|
|
|
/* the process need read permission on control file */
|
|
/* AV: shouldn't we check that it's been opened for read instead? */
|
|
ret = inode_permission(file_inode(cfile.file), MAY_READ);
|
|
if (ret < 0)
|
|
goto out_put_cfile;
|
|
|
|
event->cft = __file_cft(cfile.file);
|
|
if (IS_ERR(event->cft)) {
|
|
ret = PTR_ERR(event->cft);
|
|
goto out_put_cfile;
|
|
}
|
|
|
|
if (!event->cft->ss) {
|
|
ret = -EBADF;
|
|
goto out_put_cfile;
|
|
}
|
|
|
|
/*
|
|
* Determine the css of @cfile, verify it belongs to the same
|
|
* cgroup as cgroup.event_control, and associate @event with it.
|
|
* Remaining events are automatically removed on cgroup destruction
|
|
* but the removal is asynchronous, so take an extra ref.
|
|
*/
|
|
rcu_read_lock();
|
|
|
|
ret = -EINVAL;
|
|
event->css = cgroup_css(cgrp, event->cft->ss);
|
|
cfile_css = css_from_dir(cfile.file->f_dentry->d_parent, event->cft->ss);
|
|
if (event->css && event->css == cfile_css && css_tryget(event->css))
|
|
ret = 0;
|
|
|
|
rcu_read_unlock();
|
|
if (ret)
|
|
goto out_put_cfile;
|
|
|
|
if (!event->cft->register_event || !event->cft->unregister_event) {
|
|
ret = -EINVAL;
|
|
goto out_put_css;
|
|
}
|
|
|
|
ret = event->cft->register_event(event->css, event->cft,
|
|
event->eventfd, buffer);
|
|
if (ret)
|
|
goto out_put_css;
|
|
|
|
efile.file->f_op->poll(efile.file, &event->pt);
|
|
|
|
spin_lock(&cgrp->event_list_lock);
|
|
list_add(&event->list, &cgrp->event_list);
|
|
spin_unlock(&cgrp->event_list_lock);
|
|
|
|
fdput(cfile);
|
|
fdput(efile);
|
|
|
|
return 0;
|
|
|
|
out_put_css:
|
|
css_put(event->css);
|
|
out_put_cfile:
|
|
fdput(cfile);
|
|
out_put_eventfd:
|
|
eventfd_ctx_put(event->eventfd);
|
|
out_put_efile:
|
|
fdput(efile);
|
|
out_kfree:
|
|
kfree(event);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static struct cftype mem_cgroup_files[] = {
|
|
{
|
|
.name = "usage_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_MEM, RES_USAGE),
|
|
.read = mem_cgroup_read,
|
|
.register_event = mem_cgroup_usage_register_event,
|
|
.unregister_event = mem_cgroup_usage_unregister_event,
|
|
},
|
|
{
|
|
.name = "max_usage_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE),
|
|
.trigger = mem_cgroup_reset,
|
|
.read = mem_cgroup_read,
|
|
},
|
|
{
|
|
.name = "limit_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_MEM, RES_LIMIT),
|
|
.write_string = mem_cgroup_write,
|
|
.read = mem_cgroup_read,
|
|
},
|
|
{
|
|
.name = "soft_limit_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT),
|
|
.write_string = mem_cgroup_write,
|
|
.read = mem_cgroup_read,
|
|
},
|
|
{
|
|
.name = "failcnt",
|
|
.private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT),
|
|
.trigger = mem_cgroup_reset,
|
|
.read = mem_cgroup_read,
|
|
},
|
|
{
|
|
.name = "stat",
|
|
.read_seq_string = memcg_stat_show,
|
|
},
|
|
{
|
|
.name = "force_empty",
|
|
.trigger = mem_cgroup_force_empty_write,
|
|
},
|
|
{
|
|
.name = "use_hierarchy",
|
|
.flags = CFTYPE_INSANE,
|
|
.write_u64 = mem_cgroup_hierarchy_write,
|
|
.read_u64 = mem_cgroup_hierarchy_read,
|
|
},
|
|
{
|
|
.name = "cgroup.event_control",
|
|
.write_string = cgroup_write_event_control,
|
|
.flags = CFTYPE_NO_PREFIX,
|
|
.mode = S_IWUGO,
|
|
},
|
|
{
|
|
.name = "swappiness",
|
|
.read_u64 = mem_cgroup_swappiness_read,
|
|
.write_u64 = mem_cgroup_swappiness_write,
|
|
},
|
|
{
|
|
.name = "move_charge_at_immigrate",
|
|
.read_u64 = mem_cgroup_move_charge_read,
|
|
.write_u64 = mem_cgroup_move_charge_write,
|
|
},
|
|
{
|
|
.name = "oom_control",
|
|
.read_map = mem_cgroup_oom_control_read,
|
|
.write_u64 = mem_cgroup_oom_control_write,
|
|
.register_event = mem_cgroup_oom_register_event,
|
|
.unregister_event = mem_cgroup_oom_unregister_event,
|
|
.private = MEMFILE_PRIVATE(_OOM_TYPE, OOM_CONTROL),
|
|
},
|
|
{
|
|
.name = "pressure_level",
|
|
.register_event = vmpressure_register_event,
|
|
.unregister_event = vmpressure_unregister_event,
|
|
},
|
|
#ifdef CONFIG_NUMA
|
|
{
|
|
.name = "numa_stat",
|
|
.read_seq_string = memcg_numa_stat_show,
|
|
},
|
|
#endif
|
|
#ifdef CONFIG_MEMCG_KMEM
|
|
{
|
|
.name = "kmem.limit_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_KMEM, RES_LIMIT),
|
|
.write_string = mem_cgroup_write,
|
|
.read = mem_cgroup_read,
|
|
},
|
|
{
|
|
.name = "kmem.usage_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_KMEM, RES_USAGE),
|
|
.read = mem_cgroup_read,
|
|
},
|
|
{
|
|
.name = "kmem.failcnt",
|
|
.private = MEMFILE_PRIVATE(_KMEM, RES_FAILCNT),
|
|
.trigger = mem_cgroup_reset,
|
|
.read = mem_cgroup_read,
|
|
},
|
|
{
|
|
.name = "kmem.max_usage_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_KMEM, RES_MAX_USAGE),
|
|
.trigger = mem_cgroup_reset,
|
|
.read = mem_cgroup_read,
|
|
},
|
|
#ifdef CONFIG_SLABINFO
|
|
{
|
|
.name = "kmem.slabinfo",
|
|
.read_seq_string = mem_cgroup_slabinfo_read,
|
|
},
|
|
#endif
|
|
#endif
|
|
{ }, /* terminate */
|
|
};
|
|
|
|
#ifdef CONFIG_MEMCG_SWAP
|
|
static struct cftype memsw_cgroup_files[] = {
|
|
{
|
|
.name = "memsw.usage_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE),
|
|
.read = mem_cgroup_read,
|
|
.register_event = mem_cgroup_usage_register_event,
|
|
.unregister_event = mem_cgroup_usage_unregister_event,
|
|
},
|
|
{
|
|
.name = "memsw.max_usage_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE),
|
|
.trigger = mem_cgroup_reset,
|
|
.read = mem_cgroup_read,
|
|
},
|
|
{
|
|
.name = "memsw.limit_in_bytes",
|
|
.private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT),
|
|
.write_string = mem_cgroup_write,
|
|
.read = mem_cgroup_read,
|
|
},
|
|
{
|
|
.name = "memsw.failcnt",
|
|
.private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT),
|
|
.trigger = mem_cgroup_reset,
|
|
.read = mem_cgroup_read,
|
|
},
|
|
{ }, /* terminate */
|
|
};
|
|
#endif
|
|
static int alloc_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node)
|
|
{
|
|
struct mem_cgroup_per_node *pn;
|
|
struct mem_cgroup_per_zone *mz;
|
|
int zone, tmp = node;
|
|
/*
|
|
* This routine is called against possible nodes.
|
|
* But it's BUG to call kmalloc() against offline node.
|
|
*
|
|
* TODO: this routine can waste much memory for nodes which will
|
|
* never be onlined. It's better to use memory hotplug callback
|
|
* function.
|
|
*/
|
|
if (!node_state(node, N_NORMAL_MEMORY))
|
|
tmp = -1;
|
|
pn = kzalloc_node(sizeof(*pn), GFP_KERNEL, tmp);
|
|
if (!pn)
|
|
return 1;
|
|
|
|
for (zone = 0; zone < MAX_NR_ZONES; zone++) {
|
|
mz = &pn->zoneinfo[zone];
|
|
lruvec_init(&mz->lruvec);
|
|
mz->usage_in_excess = 0;
|
|
mz->on_tree = false;
|
|
mz->memcg = memcg;
|
|
}
|
|
memcg->nodeinfo[node] = pn;
|
|
return 0;
|
|
}
|
|
|
|
static void free_mem_cgroup_per_zone_info(struct mem_cgroup *memcg, int node)
|
|
{
|
|
kfree(memcg->nodeinfo[node]);
|
|
}
|
|
|
|
static struct mem_cgroup *mem_cgroup_alloc(void)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
size_t size = memcg_size();
|
|
|
|
/* Can be very big if nr_node_ids is very big */
|
|
if (size < PAGE_SIZE)
|
|
memcg = kzalloc(size, GFP_KERNEL);
|
|
else
|
|
memcg = vzalloc(size);
|
|
|
|
if (!memcg)
|
|
return NULL;
|
|
|
|
memcg->stat = alloc_percpu(struct mem_cgroup_stat_cpu);
|
|
if (!memcg->stat)
|
|
goto out_free;
|
|
spin_lock_init(&memcg->pcp_counter_lock);
|
|
return memcg;
|
|
|
|
out_free:
|
|
if (size < PAGE_SIZE)
|
|
kfree(memcg);
|
|
else
|
|
vfree(memcg);
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* At destroying mem_cgroup, references from swap_cgroup can remain.
|
|
* (scanning all at force_empty is too costly...)
|
|
*
|
|
* Instead of clearing all references at force_empty, we remember
|
|
* the number of reference from swap_cgroup and free mem_cgroup when
|
|
* it goes down to 0.
|
|
*
|
|
* Removal of cgroup itself succeeds regardless of refs from swap.
|
|
*/
|
|
|
|
static void __mem_cgroup_free(struct mem_cgroup *memcg)
|
|
{
|
|
int node;
|
|
size_t size = memcg_size();
|
|
|
|
mem_cgroup_remove_from_trees(memcg);
|
|
free_css_id(&mem_cgroup_subsys, &memcg->css);
|
|
|
|
for_each_node(node)
|
|
free_mem_cgroup_per_zone_info(memcg, node);
|
|
|
|
free_percpu(memcg->stat);
|
|
|
|
/*
|
|
* We need to make sure that (at least for now), the jump label
|
|
* destruction code runs outside of the cgroup lock. This is because
|
|
* get_online_cpus(), which is called from the static_branch update,
|
|
* can't be called inside the cgroup_lock. cpusets are the ones
|
|
* enforcing this dependency, so if they ever change, we might as well.
|
|
*
|
|
* schedule_work() will guarantee this happens. Be careful if you need
|
|
* to move this code around, and make sure it is outside
|
|
* the cgroup_lock.
|
|
*/
|
|
disarm_static_keys(memcg);
|
|
if (size < PAGE_SIZE)
|
|
kfree(memcg);
|
|
else
|
|
vfree(memcg);
|
|
}
|
|
|
|
/*
|
|
* Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled.
|
|
*/
|
|
struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg)
|
|
{
|
|
if (!memcg->res.parent)
|
|
return NULL;
|
|
return mem_cgroup_from_res_counter(memcg->res.parent, res);
|
|
}
|
|
EXPORT_SYMBOL(parent_mem_cgroup);
|
|
|
|
static void __init mem_cgroup_soft_limit_tree_init(void)
|
|
{
|
|
struct mem_cgroup_tree_per_node *rtpn;
|
|
struct mem_cgroup_tree_per_zone *rtpz;
|
|
int tmp, node, zone;
|
|
|
|
for_each_node(node) {
|
|
tmp = node;
|
|
if (!node_state(node, N_NORMAL_MEMORY))
|
|
tmp = -1;
|
|
rtpn = kzalloc_node(sizeof(*rtpn), GFP_KERNEL, tmp);
|
|
BUG_ON(!rtpn);
|
|
|
|
soft_limit_tree.rb_tree_per_node[node] = rtpn;
|
|
|
|
for (zone = 0; zone < MAX_NR_ZONES; zone++) {
|
|
rtpz = &rtpn->rb_tree_per_zone[zone];
|
|
rtpz->rb_root = RB_ROOT;
|
|
spin_lock_init(&rtpz->lock);
|
|
}
|
|
}
|
|
}
|
|
|
|
static struct cgroup_subsys_state * __ref
|
|
mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
long error = -ENOMEM;
|
|
int node;
|
|
|
|
memcg = mem_cgroup_alloc();
|
|
if (!memcg)
|
|
return ERR_PTR(error);
|
|
|
|
for_each_node(node)
|
|
if (alloc_mem_cgroup_per_zone_info(memcg, node))
|
|
goto free_out;
|
|
|
|
/* root ? */
|
|
if (parent_css == NULL) {
|
|
root_mem_cgroup = memcg;
|
|
res_counter_init(&memcg->res, NULL);
|
|
res_counter_init(&memcg->memsw, NULL);
|
|
res_counter_init(&memcg->kmem, NULL);
|
|
}
|
|
|
|
memcg->last_scanned_node = MAX_NUMNODES;
|
|
INIT_LIST_HEAD(&memcg->oom_notify);
|
|
memcg->move_charge_at_immigrate = 0;
|
|
mutex_init(&memcg->thresholds_lock);
|
|
spin_lock_init(&memcg->move_lock);
|
|
vmpressure_init(&memcg->vmpressure);
|
|
|
|
return &memcg->css;
|
|
|
|
free_out:
|
|
__mem_cgroup_free(memcg);
|
|
return ERR_PTR(error);
|
|
}
|
|
|
|
static int
|
|
mem_cgroup_css_online(struct cgroup_subsys_state *css)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
struct mem_cgroup *parent = mem_cgroup_from_css(css_parent(css));
|
|
int error = 0;
|
|
|
|
if (!parent)
|
|
return 0;
|
|
|
|
mutex_lock(&memcg_create_mutex);
|
|
|
|
memcg->use_hierarchy = parent->use_hierarchy;
|
|
memcg->oom_kill_disable = parent->oom_kill_disable;
|
|
memcg->swappiness = mem_cgroup_swappiness(parent);
|
|
|
|
if (parent->use_hierarchy) {
|
|
res_counter_init(&memcg->res, &parent->res);
|
|
res_counter_init(&memcg->memsw, &parent->memsw);
|
|
res_counter_init(&memcg->kmem, &parent->kmem);
|
|
|
|
/*
|
|
* No need to take a reference to the parent because cgroup
|
|
* core guarantees its existence.
|
|
*/
|
|
} else {
|
|
res_counter_init(&memcg->res, NULL);
|
|
res_counter_init(&memcg->memsw, NULL);
|
|
res_counter_init(&memcg->kmem, NULL);
|
|
/*
|
|
* Deeper hierachy with use_hierarchy == false doesn't make
|
|
* much sense so let cgroup subsystem know about this
|
|
* unfortunate state in our controller.
|
|
*/
|
|
if (parent != root_mem_cgroup)
|
|
mem_cgroup_subsys.broken_hierarchy = true;
|
|
}
|
|
|
|
error = memcg_init_kmem(memcg, &mem_cgroup_subsys);
|
|
mutex_unlock(&memcg_create_mutex);
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* Announce all parents that a group from their hierarchy is gone.
|
|
*/
|
|
static void mem_cgroup_invalidate_reclaim_iterators(struct mem_cgroup *memcg)
|
|
{
|
|
struct mem_cgroup *parent = memcg;
|
|
|
|
while ((parent = parent_mem_cgroup(parent)))
|
|
mem_cgroup_iter_invalidate(parent);
|
|
|
|
/*
|
|
* if the root memcg is not hierarchical we have to check it
|
|
* explicitely.
|
|
*/
|
|
if (!root_mem_cgroup->use_hierarchy)
|
|
mem_cgroup_iter_invalidate(root_mem_cgroup);
|
|
}
|
|
|
|
static void mem_cgroup_css_offline(struct cgroup_subsys_state *css)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
struct cgroup *cgrp = css->cgroup;
|
|
struct cgroup_event *event, *tmp;
|
|
|
|
/*
|
|
* Unregister events and notify userspace.
|
|
* Notify userspace about cgroup removing only after rmdir of cgroup
|
|
* directory to avoid race between userspace and kernelspace.
|
|
*/
|
|
spin_lock(&cgrp->event_list_lock);
|
|
list_for_each_entry_safe(event, tmp, &cgrp->event_list, list) {
|
|
list_del_init(&event->list);
|
|
schedule_work(&event->remove);
|
|
}
|
|
spin_unlock(&cgrp->event_list_lock);
|
|
|
|
kmem_cgroup_css_offline(memcg);
|
|
|
|
mem_cgroup_invalidate_reclaim_iterators(memcg);
|
|
mem_cgroup_reparent_charges(memcg);
|
|
mem_cgroup_destroy_all_caches(memcg);
|
|
vmpressure_cleanup(&memcg->vmpressure);
|
|
}
|
|
|
|
static void mem_cgroup_css_free(struct cgroup_subsys_state *css)
|
|
{
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
|
|
memcg_destroy_kmem(memcg);
|
|
__mem_cgroup_free(memcg);
|
|
}
|
|
|
|
#ifdef CONFIG_MMU
|
|
/* Handlers for move charge at task migration. */
|
|
#define PRECHARGE_COUNT_AT_ONCE 256
|
|
static int mem_cgroup_do_precharge(unsigned long count)
|
|
{
|
|
int ret = 0;
|
|
int batch_count = PRECHARGE_COUNT_AT_ONCE;
|
|
struct mem_cgroup *memcg = mc.to;
|
|
|
|
if (mem_cgroup_is_root(memcg)) {
|
|
mc.precharge += count;
|
|
/* we don't need css_get for root */
|
|
return ret;
|
|
}
|
|
/* try to charge at once */
|
|
if (count > 1) {
|
|
struct res_counter *dummy;
|
|
/*
|
|
* "memcg" cannot be under rmdir() because we've already checked
|
|
* by cgroup_lock_live_cgroup() that it is not removed and we
|
|
* are still under the same cgroup_mutex. So we can postpone
|
|
* css_get().
|
|
*/
|
|
if (res_counter_charge(&memcg->res, PAGE_SIZE * count, &dummy))
|
|
goto one_by_one;
|
|
if (do_swap_account && res_counter_charge(&memcg->memsw,
|
|
PAGE_SIZE * count, &dummy)) {
|
|
res_counter_uncharge(&memcg->res, PAGE_SIZE * count);
|
|
goto one_by_one;
|
|
}
|
|
mc.precharge += count;
|
|
return ret;
|
|
}
|
|
one_by_one:
|
|
/* fall back to one by one charge */
|
|
while (count--) {
|
|
if (signal_pending(current)) {
|
|
ret = -EINTR;
|
|
break;
|
|
}
|
|
if (!batch_count--) {
|
|
batch_count = PRECHARGE_COUNT_AT_ONCE;
|
|
cond_resched();
|
|
}
|
|
ret = __mem_cgroup_try_charge(NULL,
|
|
GFP_KERNEL, 1, &memcg, false);
|
|
if (ret)
|
|
/* mem_cgroup_clear_mc() will do uncharge later */
|
|
return ret;
|
|
mc.precharge++;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* get_mctgt_type - get target type of moving charge
|
|
* @vma: the vma the pte to be checked belongs
|
|
* @addr: the address corresponding to the pte to be checked
|
|
* @ptent: the pte to be checked
|
|
* @target: the pointer the target page or swap ent will be stored(can be NULL)
|
|
*
|
|
* Returns
|
|
* 0(MC_TARGET_NONE): if the pte is not a target for move charge.
|
|
* 1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
|
|
* move charge. if @target is not NULL, the page is stored in target->page
|
|
* with extra refcnt got(Callers should handle it).
|
|
* 2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
|
|
* target for charge migration. if @target is not NULL, the entry is stored
|
|
* in target->ent.
|
|
*
|
|
* Called with pte lock held.
|
|
*/
|
|
union mc_target {
|
|
struct page *page;
|
|
swp_entry_t ent;
|
|
};
|
|
|
|
enum mc_target_type {
|
|
MC_TARGET_NONE = 0,
|
|
MC_TARGET_PAGE,
|
|
MC_TARGET_SWAP,
|
|
};
|
|
|
|
static struct page *mc_handle_present_pte(struct vm_area_struct *vma,
|
|
unsigned long addr, pte_t ptent)
|
|
{
|
|
struct page *page = vm_normal_page(vma, addr, ptent);
|
|
|
|
if (!page || !page_mapped(page))
|
|
return NULL;
|
|
if (PageAnon(page)) {
|
|
/* we don't move shared anon */
|
|
if (!move_anon())
|
|
return NULL;
|
|
} else if (!move_file())
|
|
/* we ignore mapcount for file pages */
|
|
return NULL;
|
|
if (!get_page_unless_zero(page))
|
|
return NULL;
|
|
|
|
return page;
|
|
}
|
|
|
|
#ifdef CONFIG_SWAP
|
|
static struct page *mc_handle_swap_pte(struct vm_area_struct *vma,
|
|
unsigned long addr, pte_t ptent, swp_entry_t *entry)
|
|
{
|
|
struct page *page = NULL;
|
|
swp_entry_t ent = pte_to_swp_entry(ptent);
|
|
|
|
if (!move_anon() || non_swap_entry(ent))
|
|
return NULL;
|
|
/*
|
|
* Because lookup_swap_cache() updates some statistics counter,
|
|
* we call find_get_page() with swapper_space directly.
|
|
*/
|
|
page = find_get_page(swap_address_space(ent), ent.val);
|
|
if (do_swap_account)
|
|
entry->val = ent.val;
|
|
|
|
return page;
|
|
}
|
|
#else
|
|
static struct page *mc_handle_swap_pte(struct vm_area_struct *vma,
|
|
unsigned long addr, pte_t ptent, swp_entry_t *entry)
|
|
{
|
|
return NULL;
|
|
}
|
|
#endif
|
|
|
|
static struct page *mc_handle_file_pte(struct vm_area_struct *vma,
|
|
unsigned long addr, pte_t ptent, swp_entry_t *entry)
|
|
{
|
|
struct page *page = NULL;
|
|
struct address_space *mapping;
|
|
pgoff_t pgoff;
|
|
|
|
if (!vma->vm_file) /* anonymous vma */
|
|
return NULL;
|
|
if (!move_file())
|
|
return NULL;
|
|
|
|
mapping = vma->vm_file->f_mapping;
|
|
if (pte_none(ptent))
|
|
pgoff = linear_page_index(vma, addr);
|
|
else /* pte_file(ptent) is true */
|
|
pgoff = pte_to_pgoff(ptent);
|
|
|
|
/* page is moved even if it's not RSS of this task(page-faulted). */
|
|
page = find_get_page(mapping, pgoff);
|
|
|
|
#ifdef CONFIG_SWAP
|
|
/* shmem/tmpfs may report page out on swap: account for that too. */
|
|
if (radix_tree_exceptional_entry(page)) {
|
|
swp_entry_t swap = radix_to_swp_entry(page);
|
|
if (do_swap_account)
|
|
*entry = swap;
|
|
page = find_get_page(swap_address_space(swap), swap.val);
|
|
}
|
|
#endif
|
|
return page;
|
|
}
|
|
|
|
static enum mc_target_type get_mctgt_type(struct vm_area_struct *vma,
|
|
unsigned long addr, pte_t ptent, union mc_target *target)
|
|
{
|
|
struct page *page = NULL;
|
|
struct page_cgroup *pc;
|
|
enum mc_target_type ret = MC_TARGET_NONE;
|
|
swp_entry_t ent = { .val = 0 };
|
|
|
|
if (pte_present(ptent))
|
|
page = mc_handle_present_pte(vma, addr, ptent);
|
|
else if (is_swap_pte(ptent))
|
|
page = mc_handle_swap_pte(vma, addr, ptent, &ent);
|
|
else if (pte_none(ptent) || pte_file(ptent))
|
|
page = mc_handle_file_pte(vma, addr, ptent, &ent);
|
|
|
|
if (!page && !ent.val)
|
|
return ret;
|
|
if (page) {
|
|
pc = lookup_page_cgroup(page);
|
|
/*
|
|
* Do only loose check w/o page_cgroup lock.
|
|
* mem_cgroup_move_account() checks the pc is valid or not under
|
|
* the lock.
|
|
*/
|
|
if (PageCgroupUsed(pc) && pc->mem_cgroup == mc.from) {
|
|
ret = MC_TARGET_PAGE;
|
|
if (target)
|
|
target->page = page;
|
|
}
|
|
if (!ret || !target)
|
|
put_page(page);
|
|
}
|
|
/* There is a swap entry and a page doesn't exist or isn't charged */
|
|
if (ent.val && !ret &&
|
|
css_id(&mc.from->css) == lookup_swap_cgroup_id(ent)) {
|
|
ret = MC_TARGET_SWAP;
|
|
if (target)
|
|
target->ent = ent;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
|
|
/*
|
|
* We don't consider swapping or file mapped pages because THP does not
|
|
* support them for now.
|
|
* Caller should make sure that pmd_trans_huge(pmd) is true.
|
|
*/
|
|
static enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma,
|
|
unsigned long addr, pmd_t pmd, union mc_target *target)
|
|
{
|
|
struct page *page = NULL;
|
|
struct page_cgroup *pc;
|
|
enum mc_target_type ret = MC_TARGET_NONE;
|
|
|
|
page = pmd_page(pmd);
|
|
VM_BUG_ON(!page || !PageHead(page));
|
|
if (!move_anon())
|
|
return ret;
|
|
pc = lookup_page_cgroup(page);
|
|
if (PageCgroupUsed(pc) && pc->mem_cgroup == mc.from) {
|
|
ret = MC_TARGET_PAGE;
|
|
if (target) {
|
|
get_page(page);
|
|
target->page = page;
|
|
}
|
|
}
|
|
return ret;
|
|
}
|
|
#else
|
|
static inline enum mc_target_type get_mctgt_type_thp(struct vm_area_struct *vma,
|
|
unsigned long addr, pmd_t pmd, union mc_target *target)
|
|
{
|
|
return MC_TARGET_NONE;
|
|
}
|
|
#endif
|
|
|
|
static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd,
|
|
unsigned long addr, unsigned long end,
|
|
struct mm_walk *walk)
|
|
{
|
|
struct vm_area_struct *vma = walk->private;
|
|
pte_t *pte;
|
|
spinlock_t *ptl;
|
|
|
|
if (pmd_trans_huge_lock(pmd, vma) == 1) {
|
|
if (get_mctgt_type_thp(vma, addr, *pmd, NULL) == MC_TARGET_PAGE)
|
|
mc.precharge += HPAGE_PMD_NR;
|
|
spin_unlock(&vma->vm_mm->page_table_lock);
|
|
return 0;
|
|
}
|
|
|
|
if (pmd_trans_unstable(pmd))
|
|
return 0;
|
|
pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
|
|
for (; addr != end; pte++, addr += PAGE_SIZE)
|
|
if (get_mctgt_type(vma, addr, *pte, NULL))
|
|
mc.precharge++; /* increment precharge temporarily */
|
|
pte_unmap_unlock(pte - 1, ptl);
|
|
cond_resched();
|
|
|
|
return 0;
|
|
}
|
|
|
|
static unsigned long mem_cgroup_count_precharge(struct mm_struct *mm)
|
|
{
|
|
unsigned long precharge;
|
|
struct vm_area_struct *vma;
|
|
|
|
down_read(&mm->mmap_sem);
|
|
for (vma = mm->mmap; vma; vma = vma->vm_next) {
|
|
struct mm_walk mem_cgroup_count_precharge_walk = {
|
|
.pmd_entry = mem_cgroup_count_precharge_pte_range,
|
|
.mm = mm,
|
|
.private = vma,
|
|
};
|
|
if (is_vm_hugetlb_page(vma))
|
|
continue;
|
|
walk_page_range(vma->vm_start, vma->vm_end,
|
|
&mem_cgroup_count_precharge_walk);
|
|
}
|
|
up_read(&mm->mmap_sem);
|
|
|
|
precharge = mc.precharge;
|
|
mc.precharge = 0;
|
|
|
|
return precharge;
|
|
}
|
|
|
|
static int mem_cgroup_precharge_mc(struct mm_struct *mm)
|
|
{
|
|
unsigned long precharge = mem_cgroup_count_precharge(mm);
|
|
|
|
VM_BUG_ON(mc.moving_task);
|
|
mc.moving_task = current;
|
|
return mem_cgroup_do_precharge(precharge);
|
|
}
|
|
|
|
/* cancels all extra charges on mc.from and mc.to, and wakes up all waiters. */
|
|
static void __mem_cgroup_clear_mc(void)
|
|
{
|
|
struct mem_cgroup *from = mc.from;
|
|
struct mem_cgroup *to = mc.to;
|
|
int i;
|
|
|
|
/* we must uncharge all the leftover precharges from mc.to */
|
|
if (mc.precharge) {
|
|
__mem_cgroup_cancel_charge(mc.to, mc.precharge);
|
|
mc.precharge = 0;
|
|
}
|
|
/*
|
|
* we didn't uncharge from mc.from at mem_cgroup_move_account(), so
|
|
* we must uncharge here.
|
|
*/
|
|
if (mc.moved_charge) {
|
|
__mem_cgroup_cancel_charge(mc.from, mc.moved_charge);
|
|
mc.moved_charge = 0;
|
|
}
|
|
/* we must fixup refcnts and charges */
|
|
if (mc.moved_swap) {
|
|
/* uncharge swap account from the old cgroup */
|
|
if (!mem_cgroup_is_root(mc.from))
|
|
res_counter_uncharge(&mc.from->memsw,
|
|
PAGE_SIZE * mc.moved_swap);
|
|
|
|
for (i = 0; i < mc.moved_swap; i++)
|
|
css_put(&mc.from->css);
|
|
|
|
if (!mem_cgroup_is_root(mc.to)) {
|
|
/*
|
|
* we charged both to->res and to->memsw, so we should
|
|
* uncharge to->res.
|
|
*/
|
|
res_counter_uncharge(&mc.to->res,
|
|
PAGE_SIZE * mc.moved_swap);
|
|
}
|
|
/* we've already done css_get(mc.to) */
|
|
mc.moved_swap = 0;
|
|
}
|
|
memcg_oom_recover(from);
|
|
memcg_oom_recover(to);
|
|
wake_up_all(&mc.waitq);
|
|
}
|
|
|
|
static void mem_cgroup_clear_mc(void)
|
|
{
|
|
struct mem_cgroup *from = mc.from;
|
|
|
|
/*
|
|
* we must clear moving_task before waking up waiters at the end of
|
|
* task migration.
|
|
*/
|
|
mc.moving_task = NULL;
|
|
__mem_cgroup_clear_mc();
|
|
spin_lock(&mc.lock);
|
|
mc.from = NULL;
|
|
mc.to = NULL;
|
|
spin_unlock(&mc.lock);
|
|
mem_cgroup_end_move(from);
|
|
}
|
|
|
|
static int mem_cgroup_can_attach(struct cgroup_subsys_state *css,
|
|
struct cgroup_taskset *tset)
|
|
{
|
|
struct task_struct *p = cgroup_taskset_first(tset);
|
|
int ret = 0;
|
|
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
|
|
unsigned long move_charge_at_immigrate;
|
|
|
|
/*
|
|
* We are now commited to this value whatever it is. Changes in this
|
|
* tunable will only affect upcoming migrations, not the current one.
|
|
* So we need to save it, and keep it going.
|
|
*/
|
|
move_charge_at_immigrate = memcg->move_charge_at_immigrate;
|
|
if (move_charge_at_immigrate) {
|
|
struct mm_struct *mm;
|
|
struct mem_cgroup *from = mem_cgroup_from_task(p);
|
|
|
|
VM_BUG_ON(from == memcg);
|
|
|
|
mm = get_task_mm(p);
|
|
if (!mm)
|
|
return 0;
|
|
/* We move charges only when we move a owner of the mm */
|
|
if (mm->owner == p) {
|
|
VM_BUG_ON(mc.from);
|
|
VM_BUG_ON(mc.to);
|
|
VM_BUG_ON(mc.precharge);
|
|
VM_BUG_ON(mc.moved_charge);
|
|
VM_BUG_ON(mc.moved_swap);
|
|
mem_cgroup_start_move(from);
|
|
spin_lock(&mc.lock);
|
|
mc.from = from;
|
|
mc.to = memcg;
|
|
mc.immigrate_flags = move_charge_at_immigrate;
|
|
spin_unlock(&mc.lock);
|
|
/* We set mc.moving_task later */
|
|
|
|
ret = mem_cgroup_precharge_mc(mm);
|
|
if (ret)
|
|
mem_cgroup_clear_mc();
|
|
}
|
|
mmput(mm);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static void mem_cgroup_cancel_attach(struct cgroup_subsys_state *css,
|
|
struct cgroup_taskset *tset)
|
|
{
|
|
mem_cgroup_clear_mc();
|
|
}
|
|
|
|
static int mem_cgroup_move_charge_pte_range(pmd_t *pmd,
|
|
unsigned long addr, unsigned long end,
|
|
struct mm_walk *walk)
|
|
{
|
|
int ret = 0;
|
|
struct vm_area_struct *vma = walk->private;
|
|
pte_t *pte;
|
|
spinlock_t *ptl;
|
|
enum mc_target_type target_type;
|
|
union mc_target target;
|
|
struct page *page;
|
|
struct page_cgroup *pc;
|
|
|
|
/*
|
|
* We don't take compound_lock() here but no race with splitting thp
|
|
* happens because:
|
|
* - if pmd_trans_huge_lock() returns 1, the relevant thp is not
|
|
* under splitting, which means there's no concurrent thp split,
|
|
* - if another thread runs into split_huge_page() just after we
|
|
* entered this if-block, the thread must wait for page table lock
|
|
* to be unlocked in __split_huge_page_splitting(), where the main
|
|
* part of thp split is not executed yet.
|
|
*/
|
|
if (pmd_trans_huge_lock(pmd, vma) == 1) {
|
|
if (mc.precharge < HPAGE_PMD_NR) {
|
|
spin_unlock(&vma->vm_mm->page_table_lock);
|
|
return 0;
|
|
}
|
|
target_type = get_mctgt_type_thp(vma, addr, *pmd, &target);
|
|
if (target_type == MC_TARGET_PAGE) {
|
|
page = target.page;
|
|
if (!isolate_lru_page(page)) {
|
|
pc = lookup_page_cgroup(page);
|
|
if (!mem_cgroup_move_account(page, HPAGE_PMD_NR,
|
|
pc, mc.from, mc.to)) {
|
|
mc.precharge -= HPAGE_PMD_NR;
|
|
mc.moved_charge += HPAGE_PMD_NR;
|
|
}
|
|
putback_lru_page(page);
|
|
}
|
|
put_page(page);
|
|
}
|
|
spin_unlock(&vma->vm_mm->page_table_lock);
|
|
return 0;
|
|
}
|
|
|
|
if (pmd_trans_unstable(pmd))
|
|
return 0;
|
|
retry:
|
|
pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
|
|
for (; addr != end; addr += PAGE_SIZE) {
|
|
pte_t ptent = *(pte++);
|
|
swp_entry_t ent;
|
|
|
|
if (!mc.precharge)
|
|
break;
|
|
|
|
switch (get_mctgt_type(vma, addr, ptent, &target)) {
|
|
case MC_TARGET_PAGE:
|
|
page = target.page;
|
|
if (isolate_lru_page(page))
|
|
goto put;
|
|
pc = lookup_page_cgroup(page);
|
|
if (!mem_cgroup_move_account(page, 1, pc,
|
|
mc.from, mc.to)) {
|
|
mc.precharge--;
|
|
/* we uncharge from mc.from later. */
|
|
mc.moved_charge++;
|
|
}
|
|
putback_lru_page(page);
|
|
put: /* get_mctgt_type() gets the page */
|
|
put_page(page);
|
|
break;
|
|
case MC_TARGET_SWAP:
|
|
ent = target.ent;
|
|
if (!mem_cgroup_move_swap_account(ent, mc.from, mc.to)) {
|
|
mc.precharge--;
|
|
/* we fixup refcnts and charges later. */
|
|
mc.moved_swap++;
|
|
}
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
pte_unmap_unlock(pte - 1, ptl);
|
|
cond_resched();
|
|
|
|
if (addr != end) {
|
|
/*
|
|
* We have consumed all precharges we got in can_attach().
|
|
* We try charge one by one, but don't do any additional
|
|
* charges to mc.to if we have failed in charge once in attach()
|
|
* phase.
|
|
*/
|
|
ret = mem_cgroup_do_precharge(1);
|
|
if (!ret)
|
|
goto retry;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void mem_cgroup_move_charge(struct mm_struct *mm)
|
|
{
|
|
struct vm_area_struct *vma;
|
|
|
|
lru_add_drain_all();
|
|
retry:
|
|
if (unlikely(!down_read_trylock(&mm->mmap_sem))) {
|
|
/*
|
|
* Someone who are holding the mmap_sem might be waiting in
|
|
* waitq. So we cancel all extra charges, wake up all waiters,
|
|
* and retry. Because we cancel precharges, we might not be able
|
|
* to move enough charges, but moving charge is a best-effort
|
|
* feature anyway, so it wouldn't be a big problem.
|
|
*/
|
|
__mem_cgroup_clear_mc();
|
|
cond_resched();
|
|
goto retry;
|
|
}
|
|
for (vma = mm->mmap; vma; vma = vma->vm_next) {
|
|
int ret;
|
|
struct mm_walk mem_cgroup_move_charge_walk = {
|
|
.pmd_entry = mem_cgroup_move_charge_pte_range,
|
|
.mm = mm,
|
|
.private = vma,
|
|
};
|
|
if (is_vm_hugetlb_page(vma))
|
|
continue;
|
|
ret = walk_page_range(vma->vm_start, vma->vm_end,
|
|
&mem_cgroup_move_charge_walk);
|
|
if (ret)
|
|
/*
|
|
* means we have consumed all precharges and failed in
|
|
* doing additional charge. Just abandon here.
|
|
*/
|
|
break;
|
|
}
|
|
up_read(&mm->mmap_sem);
|
|
}
|
|
|
|
static void mem_cgroup_move_task(struct cgroup_subsys_state *css,
|
|
struct cgroup_taskset *tset)
|
|
{
|
|
struct task_struct *p = cgroup_taskset_first(tset);
|
|
struct mm_struct *mm = get_task_mm(p);
|
|
|
|
if (mm) {
|
|
if (mc.to)
|
|
mem_cgroup_move_charge(mm);
|
|
mmput(mm);
|
|
}
|
|
if (mc.to)
|
|
mem_cgroup_clear_mc();
|
|
}
|
|
#else /* !CONFIG_MMU */
|
|
static int mem_cgroup_can_attach(struct cgroup_subsys_state *css,
|
|
struct cgroup_taskset *tset)
|
|
{
|
|
return 0;
|
|
}
|
|
static void mem_cgroup_cancel_attach(struct cgroup_subsys_state *css,
|
|
struct cgroup_taskset *tset)
|
|
{
|
|
}
|
|
static void mem_cgroup_move_task(struct cgroup_subsys_state *css,
|
|
struct cgroup_taskset *tset)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* Cgroup retains root cgroups across [un]mount cycles making it necessary
|
|
* to verify sane_behavior flag on each mount attempt.
|
|
*/
|
|
static void mem_cgroup_bind(struct cgroup_subsys_state *root_css)
|
|
{
|
|
/*
|
|
* use_hierarchy is forced with sane_behavior. cgroup core
|
|
* guarantees that @root doesn't have any children, so turning it
|
|
* on for the root memcg is enough.
|
|
*/
|
|
if (cgroup_sane_behavior(root_css->cgroup))
|
|
mem_cgroup_from_css(root_css)->use_hierarchy = true;
|
|
}
|
|
|
|
struct cgroup_subsys mem_cgroup_subsys = {
|
|
.name = "memory",
|
|
.subsys_id = mem_cgroup_subsys_id,
|
|
.css_alloc = mem_cgroup_css_alloc,
|
|
.css_online = mem_cgroup_css_online,
|
|
.css_offline = mem_cgroup_css_offline,
|
|
.css_free = mem_cgroup_css_free,
|
|
.can_attach = mem_cgroup_can_attach,
|
|
.cancel_attach = mem_cgroup_cancel_attach,
|
|
.attach = mem_cgroup_move_task,
|
|
.bind = mem_cgroup_bind,
|
|
.base_cftypes = mem_cgroup_files,
|
|
.early_init = 0,
|
|
.use_id = 1,
|
|
};
|
|
|
|
#ifdef CONFIG_MEMCG_SWAP
|
|
static int __init enable_swap_account(char *s)
|
|
{
|
|
if (!strcmp(s, "1"))
|
|
really_do_swap_account = 1;
|
|
else if (!strcmp(s, "0"))
|
|
really_do_swap_account = 0;
|
|
return 1;
|
|
}
|
|
__setup("swapaccount=", enable_swap_account);
|
|
|
|
static void __init memsw_file_init(void)
|
|
{
|
|
WARN_ON(cgroup_add_cftypes(&mem_cgroup_subsys, memsw_cgroup_files));
|
|
}
|
|
|
|
static void __init enable_swap_cgroup(void)
|
|
{
|
|
if (!mem_cgroup_disabled() && really_do_swap_account) {
|
|
do_swap_account = 1;
|
|
memsw_file_init();
|
|
}
|
|
}
|
|
|
|
#else
|
|
static void __init enable_swap_cgroup(void)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* subsys_initcall() for memory controller.
|
|
*
|
|
* Some parts like hotcpu_notifier() have to be initialized from this context
|
|
* because of lock dependencies (cgroup_lock -> cpu hotplug) but basically
|
|
* everything that doesn't depend on a specific mem_cgroup structure should
|
|
* be initialized from here.
|
|
*/
|
|
static int __init mem_cgroup_init(void)
|
|
{
|
|
hotcpu_notifier(memcg_cpu_hotplug_callback, 0);
|
|
enable_swap_cgroup();
|
|
mem_cgroup_soft_limit_tree_init();
|
|
memcg_stock_init();
|
|
return 0;
|
|
}
|
|
subsys_initcall(mem_cgroup_init);
|