6296e5d3c0
* 'slab/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux: slub: disallow changing cpu_partial from userspace for debug caches slub: add missed accounting slub: Extract get_freelist from __slab_alloc slub: Switch per cpu partial page support off for debugging slub: fix a possible memleak in __slab_alloc() slub: fix slub_max_order Documentation slub: add missed accounting slab: add taint flag outputting to debug paths. slub: add taint flag outputting to debug paths slab: introduce slab_max_order kernel parameter slab: rename slab_break_gfp_order to slab_max_order
5479 lines
128 KiB
C
5479 lines
128 KiB
C
/*
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* SLUB: A slab allocator that limits cache line use instead of queuing
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* objects in per cpu and per node lists.
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*
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* The allocator synchronizes using per slab locks or atomic operatios
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* and only uses a centralized lock to manage a pool of partial slabs.
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*
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* (C) 2007 SGI, Christoph Lameter
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* (C) 2011 Linux Foundation, Christoph Lameter
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*/
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#include <linux/mm.h>
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#include <linux/swap.h> /* struct reclaim_state */
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#include <linux/module.h>
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#include <linux/bit_spinlock.h>
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#include <linux/interrupt.h>
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#include <linux/bitops.h>
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#include <linux/slab.h>
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#include <linux/proc_fs.h>
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#include <linux/seq_file.h>
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#include <linux/kmemcheck.h>
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#include <linux/cpu.h>
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#include <linux/cpuset.h>
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#include <linux/mempolicy.h>
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#include <linux/ctype.h>
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#include <linux/debugobjects.h>
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#include <linux/kallsyms.h>
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#include <linux/memory.h>
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#include <linux/math64.h>
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#include <linux/fault-inject.h>
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#include <linux/stacktrace.h>
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#include <trace/events/kmem.h>
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/*
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* Lock order:
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* 1. slub_lock (Global Semaphore)
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* 2. node->list_lock
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* 3. slab_lock(page) (Only on some arches and for debugging)
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*
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* slub_lock
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*
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* The role of the slub_lock is to protect the list of all the slabs
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* and to synchronize major metadata changes to slab cache structures.
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*
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* The slab_lock is only used for debugging and on arches that do not
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* have the ability to do a cmpxchg_double. It only protects the second
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* double word in the page struct. Meaning
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* A. page->freelist -> List of object free in a page
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* B. page->counters -> Counters of objects
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* C. page->frozen -> frozen state
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*
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* If a slab is frozen then it is exempt from list management. It is not
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* on any list. The processor that froze the slab is the one who can
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* perform list operations on the page. Other processors may put objects
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* onto the freelist but the processor that froze the slab is the only
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* one that can retrieve the objects from the page's freelist.
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*
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* The list_lock protects the partial and full list on each node and
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* the partial slab counter. If taken then no new slabs may be added or
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* removed from the lists nor make the number of partial slabs be modified.
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* (Note that the total number of slabs is an atomic value that may be
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* modified without taking the list lock).
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*
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* The list_lock is a centralized lock and thus we avoid taking it as
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* much as possible. As long as SLUB does not have to handle partial
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* slabs, operations can continue without any centralized lock. F.e.
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* allocating a long series of objects that fill up slabs does not require
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* the list lock.
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* Interrupts are disabled during allocation and deallocation in order to
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* make the slab allocator safe to use in the context of an irq. In addition
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* interrupts are disabled to ensure that the processor does not change
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* while handling per_cpu slabs, due to kernel preemption.
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*
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* SLUB assigns one slab for allocation to each processor.
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* Allocations only occur from these slabs called cpu slabs.
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*
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* Slabs with free elements are kept on a partial list and during regular
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* operations no list for full slabs is used. If an object in a full slab is
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* freed then the slab will show up again on the partial lists.
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* We track full slabs for debugging purposes though because otherwise we
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* cannot scan all objects.
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*
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* Slabs are freed when they become empty. Teardown and setup is
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* minimal so we rely on the page allocators per cpu caches for
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* fast frees and allocs.
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*
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* Overloading of page flags that are otherwise used for LRU management.
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*
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* PageActive The slab is frozen and exempt from list processing.
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* This means that the slab is dedicated to a purpose
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* such as satisfying allocations for a specific
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* processor. Objects may be freed in the slab while
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* it is frozen but slab_free will then skip the usual
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* list operations. It is up to the processor holding
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* the slab to integrate the slab into the slab lists
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* when the slab is no longer needed.
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*
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* One use of this flag is to mark slabs that are
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* used for allocations. Then such a slab becomes a cpu
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* slab. The cpu slab may be equipped with an additional
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* freelist that allows lockless access to
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* free objects in addition to the regular freelist
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* that requires the slab lock.
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*
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* PageError Slab requires special handling due to debug
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* options set. This moves slab handling out of
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* the fast path and disables lockless freelists.
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*/
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#define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
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SLAB_TRACE | SLAB_DEBUG_FREE)
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static inline int kmem_cache_debug(struct kmem_cache *s)
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{
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#ifdef CONFIG_SLUB_DEBUG
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return unlikely(s->flags & SLAB_DEBUG_FLAGS);
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#else
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return 0;
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#endif
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}
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/*
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* Issues still to be resolved:
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*
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* - Support PAGE_ALLOC_DEBUG. Should be easy to do.
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*
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* - Variable sizing of the per node arrays
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*/
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/* Enable to test recovery from slab corruption on boot */
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#undef SLUB_RESILIENCY_TEST
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/* Enable to log cmpxchg failures */
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#undef SLUB_DEBUG_CMPXCHG
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/*
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* Mininum number of partial slabs. These will be left on the partial
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* lists even if they are empty. kmem_cache_shrink may reclaim them.
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*/
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#define MIN_PARTIAL 5
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/*
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* Maximum number of desirable partial slabs.
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* The existence of more partial slabs makes kmem_cache_shrink
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* sort the partial list by the number of objects in the.
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*/
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#define MAX_PARTIAL 10
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#define DEBUG_DEFAULT_FLAGS (SLAB_DEBUG_FREE | SLAB_RED_ZONE | \
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SLAB_POISON | SLAB_STORE_USER)
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/*
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* Debugging flags that require metadata to be stored in the slab. These get
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* disabled when slub_debug=O is used and a cache's min order increases with
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* metadata.
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*/
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#define DEBUG_METADATA_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER)
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/*
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* Set of flags that will prevent slab merging
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*/
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#define SLUB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
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SLAB_TRACE | SLAB_DESTROY_BY_RCU | SLAB_NOLEAKTRACE | \
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SLAB_FAILSLAB)
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#define SLUB_MERGE_SAME (SLAB_DEBUG_FREE | SLAB_RECLAIM_ACCOUNT | \
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SLAB_CACHE_DMA | SLAB_NOTRACK)
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#define OO_SHIFT 16
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#define OO_MASK ((1 << OO_SHIFT) - 1)
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#define MAX_OBJS_PER_PAGE 32767 /* since page.objects is u15 */
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/* Internal SLUB flags */
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#define __OBJECT_POISON 0x80000000UL /* Poison object */
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#define __CMPXCHG_DOUBLE 0x40000000UL /* Use cmpxchg_double */
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static int kmem_size = sizeof(struct kmem_cache);
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#ifdef CONFIG_SMP
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static struct notifier_block slab_notifier;
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#endif
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static enum {
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DOWN, /* No slab functionality available */
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PARTIAL, /* Kmem_cache_node works */
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UP, /* Everything works but does not show up in sysfs */
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SYSFS /* Sysfs up */
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} slab_state = DOWN;
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/* A list of all slab caches on the system */
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static DECLARE_RWSEM(slub_lock);
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static LIST_HEAD(slab_caches);
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/*
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* Tracking user of a slab.
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*/
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#define TRACK_ADDRS_COUNT 16
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struct track {
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unsigned long addr; /* Called from address */
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#ifdef CONFIG_STACKTRACE
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unsigned long addrs[TRACK_ADDRS_COUNT]; /* Called from address */
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#endif
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int cpu; /* Was running on cpu */
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int pid; /* Pid context */
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unsigned long when; /* When did the operation occur */
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};
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enum track_item { TRACK_ALLOC, TRACK_FREE };
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#ifdef CONFIG_SYSFS
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static int sysfs_slab_add(struct kmem_cache *);
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static int sysfs_slab_alias(struct kmem_cache *, const char *);
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static void sysfs_slab_remove(struct kmem_cache *);
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#else
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static inline int sysfs_slab_add(struct kmem_cache *s) { return 0; }
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static inline int sysfs_slab_alias(struct kmem_cache *s, const char *p)
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{ return 0; }
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static inline void sysfs_slab_remove(struct kmem_cache *s)
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{
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kfree(s->name);
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kfree(s);
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}
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#endif
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static inline void stat(const struct kmem_cache *s, enum stat_item si)
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{
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#ifdef CONFIG_SLUB_STATS
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__this_cpu_inc(s->cpu_slab->stat[si]);
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#endif
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}
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/********************************************************************
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* Core slab cache functions
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*******************************************************************/
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int slab_is_available(void)
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{
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return slab_state >= UP;
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}
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static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node)
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{
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return s->node[node];
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}
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/* Verify that a pointer has an address that is valid within a slab page */
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static inline int check_valid_pointer(struct kmem_cache *s,
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struct page *page, const void *object)
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{
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void *base;
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if (!object)
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return 1;
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base = page_address(page);
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if (object < base || object >= base + page->objects * s->size ||
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(object - base) % s->size) {
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return 0;
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}
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return 1;
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}
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static inline void *get_freepointer(struct kmem_cache *s, void *object)
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{
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return *(void **)(object + s->offset);
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}
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static inline void *get_freepointer_safe(struct kmem_cache *s, void *object)
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{
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void *p;
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#ifdef CONFIG_DEBUG_PAGEALLOC
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probe_kernel_read(&p, (void **)(object + s->offset), sizeof(p));
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#else
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p = get_freepointer(s, object);
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#endif
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return p;
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}
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static inline void set_freepointer(struct kmem_cache *s, void *object, void *fp)
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{
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*(void **)(object + s->offset) = fp;
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}
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/* Loop over all objects in a slab */
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#define for_each_object(__p, __s, __addr, __objects) \
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for (__p = (__addr); __p < (__addr) + (__objects) * (__s)->size;\
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__p += (__s)->size)
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/* Determine object index from a given position */
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static inline int slab_index(void *p, struct kmem_cache *s, void *addr)
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{
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return (p - addr) / s->size;
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}
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static inline size_t slab_ksize(const struct kmem_cache *s)
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{
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#ifdef CONFIG_SLUB_DEBUG
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/*
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* Debugging requires use of the padding between object
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* and whatever may come after it.
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*/
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if (s->flags & (SLAB_RED_ZONE | SLAB_POISON))
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return s->objsize;
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#endif
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/*
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* If we have the need to store the freelist pointer
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* back there or track user information then we can
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* only use the space before that information.
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*/
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if (s->flags & (SLAB_DESTROY_BY_RCU | SLAB_STORE_USER))
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return s->inuse;
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/*
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* Else we can use all the padding etc for the allocation
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*/
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return s->size;
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}
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static inline int order_objects(int order, unsigned long size, int reserved)
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{
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return ((PAGE_SIZE << order) - reserved) / size;
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}
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static inline struct kmem_cache_order_objects oo_make(int order,
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unsigned long size, int reserved)
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{
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struct kmem_cache_order_objects x = {
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(order << OO_SHIFT) + order_objects(order, size, reserved)
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};
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return x;
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}
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static inline int oo_order(struct kmem_cache_order_objects x)
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{
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return x.x >> OO_SHIFT;
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}
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static inline int oo_objects(struct kmem_cache_order_objects x)
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{
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return x.x & OO_MASK;
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}
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/*
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* Per slab locking using the pagelock
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*/
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static __always_inline void slab_lock(struct page *page)
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{
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bit_spin_lock(PG_locked, &page->flags);
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}
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static __always_inline void slab_unlock(struct page *page)
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{
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__bit_spin_unlock(PG_locked, &page->flags);
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}
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/* Interrupts must be disabled (for the fallback code to work right) */
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static inline bool __cmpxchg_double_slab(struct kmem_cache *s, struct page *page,
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void *freelist_old, unsigned long counters_old,
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void *freelist_new, unsigned long counters_new,
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const char *n)
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{
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VM_BUG_ON(!irqs_disabled());
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#ifdef CONFIG_CMPXCHG_DOUBLE
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if (s->flags & __CMPXCHG_DOUBLE) {
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if (cmpxchg_double(&page->freelist, &page->counters,
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freelist_old, counters_old,
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freelist_new, counters_new))
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return 1;
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} else
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#endif
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{
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slab_lock(page);
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if (page->freelist == freelist_old && page->counters == counters_old) {
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page->freelist = freelist_new;
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page->counters = counters_new;
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slab_unlock(page);
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return 1;
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}
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slab_unlock(page);
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}
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cpu_relax();
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stat(s, CMPXCHG_DOUBLE_FAIL);
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#ifdef SLUB_DEBUG_CMPXCHG
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printk(KERN_INFO "%s %s: cmpxchg double redo ", n, s->name);
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#endif
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return 0;
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}
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static inline bool cmpxchg_double_slab(struct kmem_cache *s, struct page *page,
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void *freelist_old, unsigned long counters_old,
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void *freelist_new, unsigned long counters_new,
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const char *n)
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{
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#ifdef CONFIG_CMPXCHG_DOUBLE
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if (s->flags & __CMPXCHG_DOUBLE) {
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if (cmpxchg_double(&page->freelist, &page->counters,
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freelist_old, counters_old,
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freelist_new, counters_new))
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return 1;
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} else
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#endif
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{
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unsigned long flags;
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local_irq_save(flags);
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slab_lock(page);
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if (page->freelist == freelist_old && page->counters == counters_old) {
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page->freelist = freelist_new;
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page->counters = counters_new;
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slab_unlock(page);
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local_irq_restore(flags);
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return 1;
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}
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slab_unlock(page);
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local_irq_restore(flags);
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}
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cpu_relax();
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stat(s, CMPXCHG_DOUBLE_FAIL);
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#ifdef SLUB_DEBUG_CMPXCHG
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printk(KERN_INFO "%s %s: cmpxchg double redo ", n, s->name);
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#endif
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return 0;
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}
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#ifdef CONFIG_SLUB_DEBUG
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/*
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* Determine a map of object in use on a page.
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*
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* Node listlock must be held to guarantee that the page does
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* not vanish from under us.
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*/
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static void get_map(struct kmem_cache *s, struct page *page, unsigned long *map)
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{
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void *p;
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void *addr = page_address(page);
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for (p = page->freelist; p; p = get_freepointer(s, p))
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set_bit(slab_index(p, s, addr), map);
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}
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|
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/*
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* Debug settings:
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*/
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#ifdef CONFIG_SLUB_DEBUG_ON
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static int slub_debug = DEBUG_DEFAULT_FLAGS;
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#else
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static int slub_debug;
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#endif
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static char *slub_debug_slabs;
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static int disable_higher_order_debug;
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/*
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* Object debugging
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*/
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static void print_section(char *text, u8 *addr, unsigned int length)
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{
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print_hex_dump(KERN_ERR, text, DUMP_PREFIX_ADDRESS, 16, 1, addr,
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length, 1);
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}
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static struct track *get_track(struct kmem_cache *s, void *object,
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enum track_item alloc)
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{
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struct track *p;
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if (s->offset)
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p = object + s->offset + sizeof(void *);
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else
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p = object + s->inuse;
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return p + alloc;
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}
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static void set_track(struct kmem_cache *s, void *object,
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enum track_item alloc, unsigned long addr)
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{
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struct track *p = get_track(s, object, alloc);
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if (addr) {
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#ifdef CONFIG_STACKTRACE
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struct stack_trace trace;
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int i;
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trace.nr_entries = 0;
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trace.max_entries = TRACK_ADDRS_COUNT;
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trace.entries = p->addrs;
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trace.skip = 3;
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save_stack_trace(&trace);
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/* See rant in lockdep.c */
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if (trace.nr_entries != 0 &&
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trace.entries[trace.nr_entries - 1] == ULONG_MAX)
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trace.nr_entries--;
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for (i = trace.nr_entries; i < TRACK_ADDRS_COUNT; i++)
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p->addrs[i] = 0;
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#endif
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p->addr = addr;
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p->cpu = smp_processor_id();
|
|
p->pid = current->pid;
|
|
p->when = jiffies;
|
|
} else
|
|
memset(p, 0, sizeof(struct track));
|
|
}
|
|
|
|
static void init_tracking(struct kmem_cache *s, void *object)
|
|
{
|
|
if (!(s->flags & SLAB_STORE_USER))
|
|
return;
|
|
|
|
set_track(s, object, TRACK_FREE, 0UL);
|
|
set_track(s, object, TRACK_ALLOC, 0UL);
|
|
}
|
|
|
|
static void print_track(const char *s, struct track *t)
|
|
{
|
|
if (!t->addr)
|
|
return;
|
|
|
|
printk(KERN_ERR "INFO: %s in %pS age=%lu cpu=%u pid=%d\n",
|
|
s, (void *)t->addr, jiffies - t->when, t->cpu, t->pid);
|
|
#ifdef CONFIG_STACKTRACE
|
|
{
|
|
int i;
|
|
for (i = 0; i < TRACK_ADDRS_COUNT; i++)
|
|
if (t->addrs[i])
|
|
printk(KERN_ERR "\t%pS\n", (void *)t->addrs[i]);
|
|
else
|
|
break;
|
|
}
|
|
#endif
|
|
}
|
|
|
|
static void print_tracking(struct kmem_cache *s, void *object)
|
|
{
|
|
if (!(s->flags & SLAB_STORE_USER))
|
|
return;
|
|
|
|
print_track("Allocated", get_track(s, object, TRACK_ALLOC));
|
|
print_track("Freed", get_track(s, object, TRACK_FREE));
|
|
}
|
|
|
|
static void print_page_info(struct page *page)
|
|
{
|
|
printk(KERN_ERR "INFO: Slab 0x%p objects=%u used=%u fp=0x%p flags=0x%04lx\n",
|
|
page, page->objects, page->inuse, page->freelist, page->flags);
|
|
|
|
}
|
|
|
|
static void slab_bug(struct kmem_cache *s, char *fmt, ...)
|
|
{
|
|
va_list args;
|
|
char buf[100];
|
|
|
|
va_start(args, fmt);
|
|
vsnprintf(buf, sizeof(buf), fmt, args);
|
|
va_end(args);
|
|
printk(KERN_ERR "========================================"
|
|
"=====================================\n");
|
|
printk(KERN_ERR "BUG %s (%s): %s\n", s->name, print_tainted(), buf);
|
|
printk(KERN_ERR "----------------------------------------"
|
|
"-------------------------------------\n\n");
|
|
}
|
|
|
|
static void slab_fix(struct kmem_cache *s, char *fmt, ...)
|
|
{
|
|
va_list args;
|
|
char buf[100];
|
|
|
|
va_start(args, fmt);
|
|
vsnprintf(buf, sizeof(buf), fmt, args);
|
|
va_end(args);
|
|
printk(KERN_ERR "FIX %s: %s\n", s->name, buf);
|
|
}
|
|
|
|
static void print_trailer(struct kmem_cache *s, struct page *page, u8 *p)
|
|
{
|
|
unsigned int off; /* Offset of last byte */
|
|
u8 *addr = page_address(page);
|
|
|
|
print_tracking(s, p);
|
|
|
|
print_page_info(page);
|
|
|
|
printk(KERN_ERR "INFO: Object 0x%p @offset=%tu fp=0x%p\n\n",
|
|
p, p - addr, get_freepointer(s, p));
|
|
|
|
if (p > addr + 16)
|
|
print_section("Bytes b4 ", p - 16, 16);
|
|
|
|
print_section("Object ", p, min_t(unsigned long, s->objsize,
|
|
PAGE_SIZE));
|
|
if (s->flags & SLAB_RED_ZONE)
|
|
print_section("Redzone ", p + s->objsize,
|
|
s->inuse - s->objsize);
|
|
|
|
if (s->offset)
|
|
off = s->offset + sizeof(void *);
|
|
else
|
|
off = s->inuse;
|
|
|
|
if (s->flags & SLAB_STORE_USER)
|
|
off += 2 * sizeof(struct track);
|
|
|
|
if (off != s->size)
|
|
/* Beginning of the filler is the free pointer */
|
|
print_section("Padding ", p + off, s->size - off);
|
|
|
|
dump_stack();
|
|
}
|
|
|
|
static void object_err(struct kmem_cache *s, struct page *page,
|
|
u8 *object, char *reason)
|
|
{
|
|
slab_bug(s, "%s", reason);
|
|
print_trailer(s, page, object);
|
|
}
|
|
|
|
static void slab_err(struct kmem_cache *s, struct page *page, char *fmt, ...)
|
|
{
|
|
va_list args;
|
|
char buf[100];
|
|
|
|
va_start(args, fmt);
|
|
vsnprintf(buf, sizeof(buf), fmt, args);
|
|
va_end(args);
|
|
slab_bug(s, "%s", buf);
|
|
print_page_info(page);
|
|
dump_stack();
|
|
}
|
|
|
|
static void init_object(struct kmem_cache *s, void *object, u8 val)
|
|
{
|
|
u8 *p = object;
|
|
|
|
if (s->flags & __OBJECT_POISON) {
|
|
memset(p, POISON_FREE, s->objsize - 1);
|
|
p[s->objsize - 1] = POISON_END;
|
|
}
|
|
|
|
if (s->flags & SLAB_RED_ZONE)
|
|
memset(p + s->objsize, val, s->inuse - s->objsize);
|
|
}
|
|
|
|
static void restore_bytes(struct kmem_cache *s, char *message, u8 data,
|
|
void *from, void *to)
|
|
{
|
|
slab_fix(s, "Restoring 0x%p-0x%p=0x%x\n", from, to - 1, data);
|
|
memset(from, data, to - from);
|
|
}
|
|
|
|
static int check_bytes_and_report(struct kmem_cache *s, struct page *page,
|
|
u8 *object, char *what,
|
|
u8 *start, unsigned int value, unsigned int bytes)
|
|
{
|
|
u8 *fault;
|
|
u8 *end;
|
|
|
|
fault = memchr_inv(start, value, bytes);
|
|
if (!fault)
|
|
return 1;
|
|
|
|
end = start + bytes;
|
|
while (end > fault && end[-1] == value)
|
|
end--;
|
|
|
|
slab_bug(s, "%s overwritten", what);
|
|
printk(KERN_ERR "INFO: 0x%p-0x%p. First byte 0x%x instead of 0x%x\n",
|
|
fault, end - 1, fault[0], value);
|
|
print_trailer(s, page, object);
|
|
|
|
restore_bytes(s, what, value, fault, end);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Object layout:
|
|
*
|
|
* object address
|
|
* Bytes of the object to be managed.
|
|
* If the freepointer may overlay the object then the free
|
|
* pointer is the first word of the object.
|
|
*
|
|
* Poisoning uses 0x6b (POISON_FREE) and the last byte is
|
|
* 0xa5 (POISON_END)
|
|
*
|
|
* object + s->objsize
|
|
* Padding to reach word boundary. This is also used for Redzoning.
|
|
* Padding is extended by another word if Redzoning is enabled and
|
|
* objsize == inuse.
|
|
*
|
|
* We fill with 0xbb (RED_INACTIVE) for inactive objects and with
|
|
* 0xcc (RED_ACTIVE) for objects in use.
|
|
*
|
|
* object + s->inuse
|
|
* Meta data starts here.
|
|
*
|
|
* A. Free pointer (if we cannot overwrite object on free)
|
|
* B. Tracking data for SLAB_STORE_USER
|
|
* C. Padding to reach required alignment boundary or at mininum
|
|
* one word if debugging is on to be able to detect writes
|
|
* before the word boundary.
|
|
*
|
|
* Padding is done using 0x5a (POISON_INUSE)
|
|
*
|
|
* object + s->size
|
|
* Nothing is used beyond s->size.
|
|
*
|
|
* If slabcaches are merged then the objsize and inuse boundaries are mostly
|
|
* ignored. And therefore no slab options that rely on these boundaries
|
|
* may be used with merged slabcaches.
|
|
*/
|
|
|
|
static int check_pad_bytes(struct kmem_cache *s, struct page *page, u8 *p)
|
|
{
|
|
unsigned long off = s->inuse; /* The end of info */
|
|
|
|
if (s->offset)
|
|
/* Freepointer is placed after the object. */
|
|
off += sizeof(void *);
|
|
|
|
if (s->flags & SLAB_STORE_USER)
|
|
/* We also have user information there */
|
|
off += 2 * sizeof(struct track);
|
|
|
|
if (s->size == off)
|
|
return 1;
|
|
|
|
return check_bytes_and_report(s, page, p, "Object padding",
|
|
p + off, POISON_INUSE, s->size - off);
|
|
}
|
|
|
|
/* Check the pad bytes at the end of a slab page */
|
|
static int slab_pad_check(struct kmem_cache *s, struct page *page)
|
|
{
|
|
u8 *start;
|
|
u8 *fault;
|
|
u8 *end;
|
|
int length;
|
|
int remainder;
|
|
|
|
if (!(s->flags & SLAB_POISON))
|
|
return 1;
|
|
|
|
start = page_address(page);
|
|
length = (PAGE_SIZE << compound_order(page)) - s->reserved;
|
|
end = start + length;
|
|
remainder = length % s->size;
|
|
if (!remainder)
|
|
return 1;
|
|
|
|
fault = memchr_inv(end - remainder, POISON_INUSE, remainder);
|
|
if (!fault)
|
|
return 1;
|
|
while (end > fault && end[-1] == POISON_INUSE)
|
|
end--;
|
|
|
|
slab_err(s, page, "Padding overwritten. 0x%p-0x%p", fault, end - 1);
|
|
print_section("Padding ", end - remainder, remainder);
|
|
|
|
restore_bytes(s, "slab padding", POISON_INUSE, end - remainder, end);
|
|
return 0;
|
|
}
|
|
|
|
static int check_object(struct kmem_cache *s, struct page *page,
|
|
void *object, u8 val)
|
|
{
|
|
u8 *p = object;
|
|
u8 *endobject = object + s->objsize;
|
|
|
|
if (s->flags & SLAB_RED_ZONE) {
|
|
if (!check_bytes_and_report(s, page, object, "Redzone",
|
|
endobject, val, s->inuse - s->objsize))
|
|
return 0;
|
|
} else {
|
|
if ((s->flags & SLAB_POISON) && s->objsize < s->inuse) {
|
|
check_bytes_and_report(s, page, p, "Alignment padding",
|
|
endobject, POISON_INUSE, s->inuse - s->objsize);
|
|
}
|
|
}
|
|
|
|
if (s->flags & SLAB_POISON) {
|
|
if (val != SLUB_RED_ACTIVE && (s->flags & __OBJECT_POISON) &&
|
|
(!check_bytes_and_report(s, page, p, "Poison", p,
|
|
POISON_FREE, s->objsize - 1) ||
|
|
!check_bytes_and_report(s, page, p, "Poison",
|
|
p + s->objsize - 1, POISON_END, 1)))
|
|
return 0;
|
|
/*
|
|
* check_pad_bytes cleans up on its own.
|
|
*/
|
|
check_pad_bytes(s, page, p);
|
|
}
|
|
|
|
if (!s->offset && val == SLUB_RED_ACTIVE)
|
|
/*
|
|
* Object and freepointer overlap. Cannot check
|
|
* freepointer while object is allocated.
|
|
*/
|
|
return 1;
|
|
|
|
/* Check free pointer validity */
|
|
if (!check_valid_pointer(s, page, get_freepointer(s, p))) {
|
|
object_err(s, page, p, "Freepointer corrupt");
|
|
/*
|
|
* No choice but to zap it and thus lose the remainder
|
|
* of the free objects in this slab. May cause
|
|
* another error because the object count is now wrong.
|
|
*/
|
|
set_freepointer(s, p, NULL);
|
|
return 0;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
static int check_slab(struct kmem_cache *s, struct page *page)
|
|
{
|
|
int maxobj;
|
|
|
|
VM_BUG_ON(!irqs_disabled());
|
|
|
|
if (!PageSlab(page)) {
|
|
slab_err(s, page, "Not a valid slab page");
|
|
return 0;
|
|
}
|
|
|
|
maxobj = order_objects(compound_order(page), s->size, s->reserved);
|
|
if (page->objects > maxobj) {
|
|
slab_err(s, page, "objects %u > max %u",
|
|
s->name, page->objects, maxobj);
|
|
return 0;
|
|
}
|
|
if (page->inuse > page->objects) {
|
|
slab_err(s, page, "inuse %u > max %u",
|
|
s->name, page->inuse, page->objects);
|
|
return 0;
|
|
}
|
|
/* Slab_pad_check fixes things up after itself */
|
|
slab_pad_check(s, page);
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Determine if a certain object on a page is on the freelist. Must hold the
|
|
* slab lock to guarantee that the chains are in a consistent state.
|
|
*/
|
|
static int on_freelist(struct kmem_cache *s, struct page *page, void *search)
|
|
{
|
|
int nr = 0;
|
|
void *fp;
|
|
void *object = NULL;
|
|
unsigned long max_objects;
|
|
|
|
fp = page->freelist;
|
|
while (fp && nr <= page->objects) {
|
|
if (fp == search)
|
|
return 1;
|
|
if (!check_valid_pointer(s, page, fp)) {
|
|
if (object) {
|
|
object_err(s, page, object,
|
|
"Freechain corrupt");
|
|
set_freepointer(s, object, NULL);
|
|
break;
|
|
} else {
|
|
slab_err(s, page, "Freepointer corrupt");
|
|
page->freelist = NULL;
|
|
page->inuse = page->objects;
|
|
slab_fix(s, "Freelist cleared");
|
|
return 0;
|
|
}
|
|
break;
|
|
}
|
|
object = fp;
|
|
fp = get_freepointer(s, object);
|
|
nr++;
|
|
}
|
|
|
|
max_objects = order_objects(compound_order(page), s->size, s->reserved);
|
|
if (max_objects > MAX_OBJS_PER_PAGE)
|
|
max_objects = MAX_OBJS_PER_PAGE;
|
|
|
|
if (page->objects != max_objects) {
|
|
slab_err(s, page, "Wrong number of objects. Found %d but "
|
|
"should be %d", page->objects, max_objects);
|
|
page->objects = max_objects;
|
|
slab_fix(s, "Number of objects adjusted.");
|
|
}
|
|
if (page->inuse != page->objects - nr) {
|
|
slab_err(s, page, "Wrong object count. Counter is %d but "
|
|
"counted were %d", page->inuse, page->objects - nr);
|
|
page->inuse = page->objects - nr;
|
|
slab_fix(s, "Object count adjusted.");
|
|
}
|
|
return search == NULL;
|
|
}
|
|
|
|
static void trace(struct kmem_cache *s, struct page *page, void *object,
|
|
int alloc)
|
|
{
|
|
if (s->flags & SLAB_TRACE) {
|
|
printk(KERN_INFO "TRACE %s %s 0x%p inuse=%d fp=0x%p\n",
|
|
s->name,
|
|
alloc ? "alloc" : "free",
|
|
object, page->inuse,
|
|
page->freelist);
|
|
|
|
if (!alloc)
|
|
print_section("Object ", (void *)object, s->objsize);
|
|
|
|
dump_stack();
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Hooks for other subsystems that check memory allocations. In a typical
|
|
* production configuration these hooks all should produce no code at all.
|
|
*/
|
|
static inline int slab_pre_alloc_hook(struct kmem_cache *s, gfp_t flags)
|
|
{
|
|
flags &= gfp_allowed_mask;
|
|
lockdep_trace_alloc(flags);
|
|
might_sleep_if(flags & __GFP_WAIT);
|
|
|
|
return should_failslab(s->objsize, flags, s->flags);
|
|
}
|
|
|
|
static inline void slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags, void *object)
|
|
{
|
|
flags &= gfp_allowed_mask;
|
|
kmemcheck_slab_alloc(s, flags, object, slab_ksize(s));
|
|
kmemleak_alloc_recursive(object, s->objsize, 1, s->flags, flags);
|
|
}
|
|
|
|
static inline void slab_free_hook(struct kmem_cache *s, void *x)
|
|
{
|
|
kmemleak_free_recursive(x, s->flags);
|
|
|
|
/*
|
|
* Trouble is that we may no longer disable interupts in the fast path
|
|
* So in order to make the debug calls that expect irqs to be
|
|
* disabled we need to disable interrupts temporarily.
|
|
*/
|
|
#if defined(CONFIG_KMEMCHECK) || defined(CONFIG_LOCKDEP)
|
|
{
|
|
unsigned long flags;
|
|
|
|
local_irq_save(flags);
|
|
kmemcheck_slab_free(s, x, s->objsize);
|
|
debug_check_no_locks_freed(x, s->objsize);
|
|
local_irq_restore(flags);
|
|
}
|
|
#endif
|
|
if (!(s->flags & SLAB_DEBUG_OBJECTS))
|
|
debug_check_no_obj_freed(x, s->objsize);
|
|
}
|
|
|
|
/*
|
|
* Tracking of fully allocated slabs for debugging purposes.
|
|
*
|
|
* list_lock must be held.
|
|
*/
|
|
static void add_full(struct kmem_cache *s,
|
|
struct kmem_cache_node *n, struct page *page)
|
|
{
|
|
if (!(s->flags & SLAB_STORE_USER))
|
|
return;
|
|
|
|
list_add(&page->lru, &n->full);
|
|
}
|
|
|
|
/*
|
|
* list_lock must be held.
|
|
*/
|
|
static void remove_full(struct kmem_cache *s, struct page *page)
|
|
{
|
|
if (!(s->flags & SLAB_STORE_USER))
|
|
return;
|
|
|
|
list_del(&page->lru);
|
|
}
|
|
|
|
/* Tracking of the number of slabs for debugging purposes */
|
|
static inline unsigned long slabs_node(struct kmem_cache *s, int node)
|
|
{
|
|
struct kmem_cache_node *n = get_node(s, node);
|
|
|
|
return atomic_long_read(&n->nr_slabs);
|
|
}
|
|
|
|
static inline unsigned long node_nr_slabs(struct kmem_cache_node *n)
|
|
{
|
|
return atomic_long_read(&n->nr_slabs);
|
|
}
|
|
|
|
static inline void inc_slabs_node(struct kmem_cache *s, int node, int objects)
|
|
{
|
|
struct kmem_cache_node *n = get_node(s, node);
|
|
|
|
/*
|
|
* May be called early in order to allocate a slab for the
|
|
* kmem_cache_node structure. Solve the chicken-egg
|
|
* dilemma by deferring the increment of the count during
|
|
* bootstrap (see early_kmem_cache_node_alloc).
|
|
*/
|
|
if (n) {
|
|
atomic_long_inc(&n->nr_slabs);
|
|
atomic_long_add(objects, &n->total_objects);
|
|
}
|
|
}
|
|
static inline void dec_slabs_node(struct kmem_cache *s, int node, int objects)
|
|
{
|
|
struct kmem_cache_node *n = get_node(s, node);
|
|
|
|
atomic_long_dec(&n->nr_slabs);
|
|
atomic_long_sub(objects, &n->total_objects);
|
|
}
|
|
|
|
/* Object debug checks for alloc/free paths */
|
|
static void setup_object_debug(struct kmem_cache *s, struct page *page,
|
|
void *object)
|
|
{
|
|
if (!(s->flags & (SLAB_STORE_USER|SLAB_RED_ZONE|__OBJECT_POISON)))
|
|
return;
|
|
|
|
init_object(s, object, SLUB_RED_INACTIVE);
|
|
init_tracking(s, object);
|
|
}
|
|
|
|
static noinline int alloc_debug_processing(struct kmem_cache *s, struct page *page,
|
|
void *object, unsigned long addr)
|
|
{
|
|
if (!check_slab(s, page))
|
|
goto bad;
|
|
|
|
if (!check_valid_pointer(s, page, object)) {
|
|
object_err(s, page, object, "Freelist Pointer check fails");
|
|
goto bad;
|
|
}
|
|
|
|
if (!check_object(s, page, object, SLUB_RED_INACTIVE))
|
|
goto bad;
|
|
|
|
/* Success perform special debug activities for allocs */
|
|
if (s->flags & SLAB_STORE_USER)
|
|
set_track(s, object, TRACK_ALLOC, addr);
|
|
trace(s, page, object, 1);
|
|
init_object(s, object, SLUB_RED_ACTIVE);
|
|
return 1;
|
|
|
|
bad:
|
|
if (PageSlab(page)) {
|
|
/*
|
|
* If this is a slab page then lets do the best we can
|
|
* to avoid issues in the future. Marking all objects
|
|
* as used avoids touching the remaining objects.
|
|
*/
|
|
slab_fix(s, "Marking all objects used");
|
|
page->inuse = page->objects;
|
|
page->freelist = NULL;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static noinline int free_debug_processing(struct kmem_cache *s,
|
|
struct page *page, void *object, unsigned long addr)
|
|
{
|
|
unsigned long flags;
|
|
int rc = 0;
|
|
|
|
local_irq_save(flags);
|
|
slab_lock(page);
|
|
|
|
if (!check_slab(s, page))
|
|
goto fail;
|
|
|
|
if (!check_valid_pointer(s, page, object)) {
|
|
slab_err(s, page, "Invalid object pointer 0x%p", object);
|
|
goto fail;
|
|
}
|
|
|
|
if (on_freelist(s, page, object)) {
|
|
object_err(s, page, object, "Object already free");
|
|
goto fail;
|
|
}
|
|
|
|
if (!check_object(s, page, object, SLUB_RED_ACTIVE))
|
|
goto out;
|
|
|
|
if (unlikely(s != page->slab)) {
|
|
if (!PageSlab(page)) {
|
|
slab_err(s, page, "Attempt to free object(0x%p) "
|
|
"outside of slab", object);
|
|
} else if (!page->slab) {
|
|
printk(KERN_ERR
|
|
"SLUB <none>: no slab for object 0x%p.\n",
|
|
object);
|
|
dump_stack();
|
|
} else
|
|
object_err(s, page, object,
|
|
"page slab pointer corrupt.");
|
|
goto fail;
|
|
}
|
|
|
|
if (s->flags & SLAB_STORE_USER)
|
|
set_track(s, object, TRACK_FREE, addr);
|
|
trace(s, page, object, 0);
|
|
init_object(s, object, SLUB_RED_INACTIVE);
|
|
rc = 1;
|
|
out:
|
|
slab_unlock(page);
|
|
local_irq_restore(flags);
|
|
return rc;
|
|
|
|
fail:
|
|
slab_fix(s, "Object at 0x%p not freed", object);
|
|
goto out;
|
|
}
|
|
|
|
static int __init setup_slub_debug(char *str)
|
|
{
|
|
slub_debug = DEBUG_DEFAULT_FLAGS;
|
|
if (*str++ != '=' || !*str)
|
|
/*
|
|
* No options specified. Switch on full debugging.
|
|
*/
|
|
goto out;
|
|
|
|
if (*str == ',')
|
|
/*
|
|
* No options but restriction on slabs. This means full
|
|
* debugging for slabs matching a pattern.
|
|
*/
|
|
goto check_slabs;
|
|
|
|
if (tolower(*str) == 'o') {
|
|
/*
|
|
* Avoid enabling debugging on caches if its minimum order
|
|
* would increase as a result.
|
|
*/
|
|
disable_higher_order_debug = 1;
|
|
goto out;
|
|
}
|
|
|
|
slub_debug = 0;
|
|
if (*str == '-')
|
|
/*
|
|
* Switch off all debugging measures.
|
|
*/
|
|
goto out;
|
|
|
|
/*
|
|
* Determine which debug features should be switched on
|
|
*/
|
|
for (; *str && *str != ','; str++) {
|
|
switch (tolower(*str)) {
|
|
case 'f':
|
|
slub_debug |= SLAB_DEBUG_FREE;
|
|
break;
|
|
case 'z':
|
|
slub_debug |= SLAB_RED_ZONE;
|
|
break;
|
|
case 'p':
|
|
slub_debug |= SLAB_POISON;
|
|
break;
|
|
case 'u':
|
|
slub_debug |= SLAB_STORE_USER;
|
|
break;
|
|
case 't':
|
|
slub_debug |= SLAB_TRACE;
|
|
break;
|
|
case 'a':
|
|
slub_debug |= SLAB_FAILSLAB;
|
|
break;
|
|
default:
|
|
printk(KERN_ERR "slub_debug option '%c' "
|
|
"unknown. skipped\n", *str);
|
|
}
|
|
}
|
|
|
|
check_slabs:
|
|
if (*str == ',')
|
|
slub_debug_slabs = str + 1;
|
|
out:
|
|
return 1;
|
|
}
|
|
|
|
__setup("slub_debug", setup_slub_debug);
|
|
|
|
static unsigned long kmem_cache_flags(unsigned long objsize,
|
|
unsigned long flags, const char *name,
|
|
void (*ctor)(void *))
|
|
{
|
|
/*
|
|
* Enable debugging if selected on the kernel commandline.
|
|
*/
|
|
if (slub_debug && (!slub_debug_slabs ||
|
|
!strncmp(slub_debug_slabs, name, strlen(slub_debug_slabs))))
|
|
flags |= slub_debug;
|
|
|
|
return flags;
|
|
}
|
|
#else
|
|
static inline void setup_object_debug(struct kmem_cache *s,
|
|
struct page *page, void *object) {}
|
|
|
|
static inline int alloc_debug_processing(struct kmem_cache *s,
|
|
struct page *page, void *object, unsigned long addr) { return 0; }
|
|
|
|
static inline int free_debug_processing(struct kmem_cache *s,
|
|
struct page *page, void *object, unsigned long addr) { return 0; }
|
|
|
|
static inline int slab_pad_check(struct kmem_cache *s, struct page *page)
|
|
{ return 1; }
|
|
static inline int check_object(struct kmem_cache *s, struct page *page,
|
|
void *object, u8 val) { return 1; }
|
|
static inline void add_full(struct kmem_cache *s, struct kmem_cache_node *n,
|
|
struct page *page) {}
|
|
static inline void remove_full(struct kmem_cache *s, struct page *page) {}
|
|
static inline unsigned long kmem_cache_flags(unsigned long objsize,
|
|
unsigned long flags, const char *name,
|
|
void (*ctor)(void *))
|
|
{
|
|
return flags;
|
|
}
|
|
#define slub_debug 0
|
|
|
|
#define disable_higher_order_debug 0
|
|
|
|
static inline unsigned long slabs_node(struct kmem_cache *s, int node)
|
|
{ return 0; }
|
|
static inline unsigned long node_nr_slabs(struct kmem_cache_node *n)
|
|
{ return 0; }
|
|
static inline void inc_slabs_node(struct kmem_cache *s, int node,
|
|
int objects) {}
|
|
static inline void dec_slabs_node(struct kmem_cache *s, int node,
|
|
int objects) {}
|
|
|
|
static inline int slab_pre_alloc_hook(struct kmem_cache *s, gfp_t flags)
|
|
{ return 0; }
|
|
|
|
static inline void slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags,
|
|
void *object) {}
|
|
|
|
static inline void slab_free_hook(struct kmem_cache *s, void *x) {}
|
|
|
|
#endif /* CONFIG_SLUB_DEBUG */
|
|
|
|
/*
|
|
* Slab allocation and freeing
|
|
*/
|
|
static inline struct page *alloc_slab_page(gfp_t flags, int node,
|
|
struct kmem_cache_order_objects oo)
|
|
{
|
|
int order = oo_order(oo);
|
|
|
|
flags |= __GFP_NOTRACK;
|
|
|
|
if (node == NUMA_NO_NODE)
|
|
return alloc_pages(flags, order);
|
|
else
|
|
return alloc_pages_exact_node(node, flags, order);
|
|
}
|
|
|
|
static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
|
|
{
|
|
struct page *page;
|
|
struct kmem_cache_order_objects oo = s->oo;
|
|
gfp_t alloc_gfp;
|
|
|
|
flags &= gfp_allowed_mask;
|
|
|
|
if (flags & __GFP_WAIT)
|
|
local_irq_enable();
|
|
|
|
flags |= s->allocflags;
|
|
|
|
/*
|
|
* Let the initial higher-order allocation fail under memory pressure
|
|
* so we fall-back to the minimum order allocation.
|
|
*/
|
|
alloc_gfp = (flags | __GFP_NOWARN | __GFP_NORETRY) & ~__GFP_NOFAIL;
|
|
|
|
page = alloc_slab_page(alloc_gfp, node, oo);
|
|
if (unlikely(!page)) {
|
|
oo = s->min;
|
|
/*
|
|
* Allocation may have failed due to fragmentation.
|
|
* Try a lower order alloc if possible
|
|
*/
|
|
page = alloc_slab_page(flags, node, oo);
|
|
|
|
if (page)
|
|
stat(s, ORDER_FALLBACK);
|
|
}
|
|
|
|
if (flags & __GFP_WAIT)
|
|
local_irq_disable();
|
|
|
|
if (!page)
|
|
return NULL;
|
|
|
|
if (kmemcheck_enabled
|
|
&& !(s->flags & (SLAB_NOTRACK | DEBUG_DEFAULT_FLAGS))) {
|
|
int pages = 1 << oo_order(oo);
|
|
|
|
kmemcheck_alloc_shadow(page, oo_order(oo), flags, node);
|
|
|
|
/*
|
|
* Objects from caches that have a constructor don't get
|
|
* cleared when they're allocated, so we need to do it here.
|
|
*/
|
|
if (s->ctor)
|
|
kmemcheck_mark_uninitialized_pages(page, pages);
|
|
else
|
|
kmemcheck_mark_unallocated_pages(page, pages);
|
|
}
|
|
|
|
page->objects = oo_objects(oo);
|
|
mod_zone_page_state(page_zone(page),
|
|
(s->flags & SLAB_RECLAIM_ACCOUNT) ?
|
|
NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE,
|
|
1 << oo_order(oo));
|
|
|
|
return page;
|
|
}
|
|
|
|
static void setup_object(struct kmem_cache *s, struct page *page,
|
|
void *object)
|
|
{
|
|
setup_object_debug(s, page, object);
|
|
if (unlikely(s->ctor))
|
|
s->ctor(object);
|
|
}
|
|
|
|
static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node)
|
|
{
|
|
struct page *page;
|
|
void *start;
|
|
void *last;
|
|
void *p;
|
|
|
|
BUG_ON(flags & GFP_SLAB_BUG_MASK);
|
|
|
|
page = allocate_slab(s,
|
|
flags & (GFP_RECLAIM_MASK | GFP_CONSTRAINT_MASK), node);
|
|
if (!page)
|
|
goto out;
|
|
|
|
inc_slabs_node(s, page_to_nid(page), page->objects);
|
|
page->slab = s;
|
|
page->flags |= 1 << PG_slab;
|
|
|
|
start = page_address(page);
|
|
|
|
if (unlikely(s->flags & SLAB_POISON))
|
|
memset(start, POISON_INUSE, PAGE_SIZE << compound_order(page));
|
|
|
|
last = start;
|
|
for_each_object(p, s, start, page->objects) {
|
|
setup_object(s, page, last);
|
|
set_freepointer(s, last, p);
|
|
last = p;
|
|
}
|
|
setup_object(s, page, last);
|
|
set_freepointer(s, last, NULL);
|
|
|
|
page->freelist = start;
|
|
page->inuse = page->objects;
|
|
page->frozen = 1;
|
|
out:
|
|
return page;
|
|
}
|
|
|
|
static void __free_slab(struct kmem_cache *s, struct page *page)
|
|
{
|
|
int order = compound_order(page);
|
|
int pages = 1 << order;
|
|
|
|
if (kmem_cache_debug(s)) {
|
|
void *p;
|
|
|
|
slab_pad_check(s, page);
|
|
for_each_object(p, s, page_address(page),
|
|
page->objects)
|
|
check_object(s, page, p, SLUB_RED_INACTIVE);
|
|
}
|
|
|
|
kmemcheck_free_shadow(page, compound_order(page));
|
|
|
|
mod_zone_page_state(page_zone(page),
|
|
(s->flags & SLAB_RECLAIM_ACCOUNT) ?
|
|
NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE,
|
|
-pages);
|
|
|
|
__ClearPageSlab(page);
|
|
reset_page_mapcount(page);
|
|
if (current->reclaim_state)
|
|
current->reclaim_state->reclaimed_slab += pages;
|
|
__free_pages(page, order);
|
|
}
|
|
|
|
#define need_reserve_slab_rcu \
|
|
(sizeof(((struct page *)NULL)->lru) < sizeof(struct rcu_head))
|
|
|
|
static void rcu_free_slab(struct rcu_head *h)
|
|
{
|
|
struct page *page;
|
|
|
|
if (need_reserve_slab_rcu)
|
|
page = virt_to_head_page(h);
|
|
else
|
|
page = container_of((struct list_head *)h, struct page, lru);
|
|
|
|
__free_slab(page->slab, page);
|
|
}
|
|
|
|
static void free_slab(struct kmem_cache *s, struct page *page)
|
|
{
|
|
if (unlikely(s->flags & SLAB_DESTROY_BY_RCU)) {
|
|
struct rcu_head *head;
|
|
|
|
if (need_reserve_slab_rcu) {
|
|
int order = compound_order(page);
|
|
int offset = (PAGE_SIZE << order) - s->reserved;
|
|
|
|
VM_BUG_ON(s->reserved != sizeof(*head));
|
|
head = page_address(page) + offset;
|
|
} else {
|
|
/*
|
|
* RCU free overloads the RCU head over the LRU
|
|
*/
|
|
head = (void *)&page->lru;
|
|
}
|
|
|
|
call_rcu(head, rcu_free_slab);
|
|
} else
|
|
__free_slab(s, page);
|
|
}
|
|
|
|
static void discard_slab(struct kmem_cache *s, struct page *page)
|
|
{
|
|
dec_slabs_node(s, page_to_nid(page), page->objects);
|
|
free_slab(s, page);
|
|
}
|
|
|
|
/*
|
|
* Management of partially allocated slabs.
|
|
*
|
|
* list_lock must be held.
|
|
*/
|
|
static inline void add_partial(struct kmem_cache_node *n,
|
|
struct page *page, int tail)
|
|
{
|
|
n->nr_partial++;
|
|
if (tail == DEACTIVATE_TO_TAIL)
|
|
list_add_tail(&page->lru, &n->partial);
|
|
else
|
|
list_add(&page->lru, &n->partial);
|
|
}
|
|
|
|
/*
|
|
* list_lock must be held.
|
|
*/
|
|
static inline void remove_partial(struct kmem_cache_node *n,
|
|
struct page *page)
|
|
{
|
|
list_del(&page->lru);
|
|
n->nr_partial--;
|
|
}
|
|
|
|
/*
|
|
* Lock slab, remove from the partial list and put the object into the
|
|
* per cpu freelist.
|
|
*
|
|
* Returns a list of objects or NULL if it fails.
|
|
*
|
|
* Must hold list_lock.
|
|
*/
|
|
static inline void *acquire_slab(struct kmem_cache *s,
|
|
struct kmem_cache_node *n, struct page *page,
|
|
int mode)
|
|
{
|
|
void *freelist;
|
|
unsigned long counters;
|
|
struct page new;
|
|
|
|
/*
|
|
* Zap the freelist and set the frozen bit.
|
|
* The old freelist is the list of objects for the
|
|
* per cpu allocation list.
|
|
*/
|
|
do {
|
|
freelist = page->freelist;
|
|
counters = page->counters;
|
|
new.counters = counters;
|
|
if (mode)
|
|
new.inuse = page->objects;
|
|
|
|
VM_BUG_ON(new.frozen);
|
|
new.frozen = 1;
|
|
|
|
} while (!__cmpxchg_double_slab(s, page,
|
|
freelist, counters,
|
|
NULL, new.counters,
|
|
"lock and freeze"));
|
|
|
|
remove_partial(n, page);
|
|
return freelist;
|
|
}
|
|
|
|
static int put_cpu_partial(struct kmem_cache *s, struct page *page, int drain);
|
|
|
|
/*
|
|
* Try to allocate a partial slab from a specific node.
|
|
*/
|
|
static void *get_partial_node(struct kmem_cache *s,
|
|
struct kmem_cache_node *n, struct kmem_cache_cpu *c)
|
|
{
|
|
struct page *page, *page2;
|
|
void *object = NULL;
|
|
|
|
/*
|
|
* Racy check. If we mistakenly see no partial slabs then we
|
|
* just allocate an empty slab. If we mistakenly try to get a
|
|
* partial slab and there is none available then get_partials()
|
|
* will return NULL.
|
|
*/
|
|
if (!n || !n->nr_partial)
|
|
return NULL;
|
|
|
|
spin_lock(&n->list_lock);
|
|
list_for_each_entry_safe(page, page2, &n->partial, lru) {
|
|
void *t = acquire_slab(s, n, page, object == NULL);
|
|
int available;
|
|
|
|
if (!t)
|
|
break;
|
|
|
|
if (!object) {
|
|
c->page = page;
|
|
c->node = page_to_nid(page);
|
|
stat(s, ALLOC_FROM_PARTIAL);
|
|
object = t;
|
|
available = page->objects - page->inuse;
|
|
} else {
|
|
page->freelist = t;
|
|
available = put_cpu_partial(s, page, 0);
|
|
}
|
|
if (kmem_cache_debug(s) || available > s->cpu_partial / 2)
|
|
break;
|
|
|
|
}
|
|
spin_unlock(&n->list_lock);
|
|
return object;
|
|
}
|
|
|
|
/*
|
|
* Get a page from somewhere. Search in increasing NUMA distances.
|
|
*/
|
|
static struct page *get_any_partial(struct kmem_cache *s, gfp_t flags,
|
|
struct kmem_cache_cpu *c)
|
|
{
|
|
#ifdef CONFIG_NUMA
|
|
struct zonelist *zonelist;
|
|
struct zoneref *z;
|
|
struct zone *zone;
|
|
enum zone_type high_zoneidx = gfp_zone(flags);
|
|
void *object;
|
|
|
|
/*
|
|
* The defrag ratio allows a configuration of the tradeoffs between
|
|
* inter node defragmentation and node local allocations. A lower
|
|
* defrag_ratio increases the tendency to do local allocations
|
|
* instead of attempting to obtain partial slabs from other nodes.
|
|
*
|
|
* If the defrag_ratio is set to 0 then kmalloc() always
|
|
* returns node local objects. If the ratio is higher then kmalloc()
|
|
* may return off node objects because partial slabs are obtained
|
|
* from other nodes and filled up.
|
|
*
|
|
* If /sys/kernel/slab/xx/defrag_ratio is set to 100 (which makes
|
|
* defrag_ratio = 1000) then every (well almost) allocation will
|
|
* first attempt to defrag slab caches on other nodes. This means
|
|
* scanning over all nodes to look for partial slabs which may be
|
|
* expensive if we do it every time we are trying to find a slab
|
|
* with available objects.
|
|
*/
|
|
if (!s->remote_node_defrag_ratio ||
|
|
get_cycles() % 1024 > s->remote_node_defrag_ratio)
|
|
return NULL;
|
|
|
|
get_mems_allowed();
|
|
zonelist = node_zonelist(slab_node(current->mempolicy), flags);
|
|
for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) {
|
|
struct kmem_cache_node *n;
|
|
|
|
n = get_node(s, zone_to_nid(zone));
|
|
|
|
if (n && cpuset_zone_allowed_hardwall(zone, flags) &&
|
|
n->nr_partial > s->min_partial) {
|
|
object = get_partial_node(s, n, c);
|
|
if (object) {
|
|
put_mems_allowed();
|
|
return object;
|
|
}
|
|
}
|
|
}
|
|
put_mems_allowed();
|
|
#endif
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* Get a partial page, lock it and return it.
|
|
*/
|
|
static void *get_partial(struct kmem_cache *s, gfp_t flags, int node,
|
|
struct kmem_cache_cpu *c)
|
|
{
|
|
void *object;
|
|
int searchnode = (node == NUMA_NO_NODE) ? numa_node_id() : node;
|
|
|
|
object = get_partial_node(s, get_node(s, searchnode), c);
|
|
if (object || node != NUMA_NO_NODE)
|
|
return object;
|
|
|
|
return get_any_partial(s, flags, c);
|
|
}
|
|
|
|
#ifdef CONFIG_PREEMPT
|
|
/*
|
|
* Calculate the next globally unique transaction for disambiguiation
|
|
* during cmpxchg. The transactions start with the cpu number and are then
|
|
* incremented by CONFIG_NR_CPUS.
|
|
*/
|
|
#define TID_STEP roundup_pow_of_two(CONFIG_NR_CPUS)
|
|
#else
|
|
/*
|
|
* No preemption supported therefore also no need to check for
|
|
* different cpus.
|
|
*/
|
|
#define TID_STEP 1
|
|
#endif
|
|
|
|
static inline unsigned long next_tid(unsigned long tid)
|
|
{
|
|
return tid + TID_STEP;
|
|
}
|
|
|
|
static inline unsigned int tid_to_cpu(unsigned long tid)
|
|
{
|
|
return tid % TID_STEP;
|
|
}
|
|
|
|
static inline unsigned long tid_to_event(unsigned long tid)
|
|
{
|
|
return tid / TID_STEP;
|
|
}
|
|
|
|
static inline unsigned int init_tid(int cpu)
|
|
{
|
|
return cpu;
|
|
}
|
|
|
|
static inline void note_cmpxchg_failure(const char *n,
|
|
const struct kmem_cache *s, unsigned long tid)
|
|
{
|
|
#ifdef SLUB_DEBUG_CMPXCHG
|
|
unsigned long actual_tid = __this_cpu_read(s->cpu_slab->tid);
|
|
|
|
printk(KERN_INFO "%s %s: cmpxchg redo ", n, s->name);
|
|
|
|
#ifdef CONFIG_PREEMPT
|
|
if (tid_to_cpu(tid) != tid_to_cpu(actual_tid))
|
|
printk("due to cpu change %d -> %d\n",
|
|
tid_to_cpu(tid), tid_to_cpu(actual_tid));
|
|
else
|
|
#endif
|
|
if (tid_to_event(tid) != tid_to_event(actual_tid))
|
|
printk("due to cpu running other code. Event %ld->%ld\n",
|
|
tid_to_event(tid), tid_to_event(actual_tid));
|
|
else
|
|
printk("for unknown reason: actual=%lx was=%lx target=%lx\n",
|
|
actual_tid, tid, next_tid(tid));
|
|
#endif
|
|
stat(s, CMPXCHG_DOUBLE_CPU_FAIL);
|
|
}
|
|
|
|
void init_kmem_cache_cpus(struct kmem_cache *s)
|
|
{
|
|
int cpu;
|
|
|
|
for_each_possible_cpu(cpu)
|
|
per_cpu_ptr(s->cpu_slab, cpu)->tid = init_tid(cpu);
|
|
}
|
|
|
|
/*
|
|
* Remove the cpu slab
|
|
*/
|
|
static void deactivate_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
|
|
{
|
|
enum slab_modes { M_NONE, M_PARTIAL, M_FULL, M_FREE };
|
|
struct page *page = c->page;
|
|
struct kmem_cache_node *n = get_node(s, page_to_nid(page));
|
|
int lock = 0;
|
|
enum slab_modes l = M_NONE, m = M_NONE;
|
|
void *freelist;
|
|
void *nextfree;
|
|
int tail = DEACTIVATE_TO_HEAD;
|
|
struct page new;
|
|
struct page old;
|
|
|
|
if (page->freelist) {
|
|
stat(s, DEACTIVATE_REMOTE_FREES);
|
|
tail = DEACTIVATE_TO_TAIL;
|
|
}
|
|
|
|
c->tid = next_tid(c->tid);
|
|
c->page = NULL;
|
|
freelist = c->freelist;
|
|
c->freelist = NULL;
|
|
|
|
/*
|
|
* Stage one: Free all available per cpu objects back
|
|
* to the page freelist while it is still frozen. Leave the
|
|
* last one.
|
|
*
|
|
* There is no need to take the list->lock because the page
|
|
* is still frozen.
|
|
*/
|
|
while (freelist && (nextfree = get_freepointer(s, freelist))) {
|
|
void *prior;
|
|
unsigned long counters;
|
|
|
|
do {
|
|
prior = page->freelist;
|
|
counters = page->counters;
|
|
set_freepointer(s, freelist, prior);
|
|
new.counters = counters;
|
|
new.inuse--;
|
|
VM_BUG_ON(!new.frozen);
|
|
|
|
} while (!__cmpxchg_double_slab(s, page,
|
|
prior, counters,
|
|
freelist, new.counters,
|
|
"drain percpu freelist"));
|
|
|
|
freelist = nextfree;
|
|
}
|
|
|
|
/*
|
|
* Stage two: Ensure that the page is unfrozen while the
|
|
* list presence reflects the actual number of objects
|
|
* during unfreeze.
|
|
*
|
|
* We setup the list membership and then perform a cmpxchg
|
|
* with the count. If there is a mismatch then the page
|
|
* is not unfrozen but the page is on the wrong list.
|
|
*
|
|
* Then we restart the process which may have to remove
|
|
* the page from the list that we just put it on again
|
|
* because the number of objects in the slab may have
|
|
* changed.
|
|
*/
|
|
redo:
|
|
|
|
old.freelist = page->freelist;
|
|
old.counters = page->counters;
|
|
VM_BUG_ON(!old.frozen);
|
|
|
|
/* Determine target state of the slab */
|
|
new.counters = old.counters;
|
|
if (freelist) {
|
|
new.inuse--;
|
|
set_freepointer(s, freelist, old.freelist);
|
|
new.freelist = freelist;
|
|
} else
|
|
new.freelist = old.freelist;
|
|
|
|
new.frozen = 0;
|
|
|
|
if (!new.inuse && n->nr_partial > s->min_partial)
|
|
m = M_FREE;
|
|
else if (new.freelist) {
|
|
m = M_PARTIAL;
|
|
if (!lock) {
|
|
lock = 1;
|
|
/*
|
|
* Taking the spinlock removes the possiblity
|
|
* that acquire_slab() will see a slab page that
|
|
* is frozen
|
|
*/
|
|
spin_lock(&n->list_lock);
|
|
}
|
|
} else {
|
|
m = M_FULL;
|
|
if (kmem_cache_debug(s) && !lock) {
|
|
lock = 1;
|
|
/*
|
|
* This also ensures that the scanning of full
|
|
* slabs from diagnostic functions will not see
|
|
* any frozen slabs.
|
|
*/
|
|
spin_lock(&n->list_lock);
|
|
}
|
|
}
|
|
|
|
if (l != m) {
|
|
|
|
if (l == M_PARTIAL)
|
|
|
|
remove_partial(n, page);
|
|
|
|
else if (l == M_FULL)
|
|
|
|
remove_full(s, page);
|
|
|
|
if (m == M_PARTIAL) {
|
|
|
|
add_partial(n, page, tail);
|
|
stat(s, tail);
|
|
|
|
} else if (m == M_FULL) {
|
|
|
|
stat(s, DEACTIVATE_FULL);
|
|
add_full(s, n, page);
|
|
|
|
}
|
|
}
|
|
|
|
l = m;
|
|
if (!__cmpxchg_double_slab(s, page,
|
|
old.freelist, old.counters,
|
|
new.freelist, new.counters,
|
|
"unfreezing slab"))
|
|
goto redo;
|
|
|
|
if (lock)
|
|
spin_unlock(&n->list_lock);
|
|
|
|
if (m == M_FREE) {
|
|
stat(s, DEACTIVATE_EMPTY);
|
|
discard_slab(s, page);
|
|
stat(s, FREE_SLAB);
|
|
}
|
|
}
|
|
|
|
/* Unfreeze all the cpu partial slabs */
|
|
static void unfreeze_partials(struct kmem_cache *s)
|
|
{
|
|
struct kmem_cache_node *n = NULL;
|
|
struct kmem_cache_cpu *c = this_cpu_ptr(s->cpu_slab);
|
|
struct page *page, *discard_page = NULL;
|
|
|
|
while ((page = c->partial)) {
|
|
enum slab_modes { M_PARTIAL, M_FREE };
|
|
enum slab_modes l, m;
|
|
struct page new;
|
|
struct page old;
|
|
|
|
c->partial = page->next;
|
|
l = M_FREE;
|
|
|
|
do {
|
|
|
|
old.freelist = page->freelist;
|
|
old.counters = page->counters;
|
|
VM_BUG_ON(!old.frozen);
|
|
|
|
new.counters = old.counters;
|
|
new.freelist = old.freelist;
|
|
|
|
new.frozen = 0;
|
|
|
|
if (!new.inuse && (!n || n->nr_partial > s->min_partial))
|
|
m = M_FREE;
|
|
else {
|
|
struct kmem_cache_node *n2 = get_node(s,
|
|
page_to_nid(page));
|
|
|
|
m = M_PARTIAL;
|
|
if (n != n2) {
|
|
if (n)
|
|
spin_unlock(&n->list_lock);
|
|
|
|
n = n2;
|
|
spin_lock(&n->list_lock);
|
|
}
|
|
}
|
|
|
|
if (l != m) {
|
|
if (l == M_PARTIAL) {
|
|
remove_partial(n, page);
|
|
stat(s, FREE_REMOVE_PARTIAL);
|
|
} else {
|
|
add_partial(n, page,
|
|
DEACTIVATE_TO_TAIL);
|
|
stat(s, FREE_ADD_PARTIAL);
|
|
}
|
|
|
|
l = m;
|
|
}
|
|
|
|
} while (!cmpxchg_double_slab(s, page,
|
|
old.freelist, old.counters,
|
|
new.freelist, new.counters,
|
|
"unfreezing slab"));
|
|
|
|
if (m == M_FREE) {
|
|
page->next = discard_page;
|
|
discard_page = page;
|
|
}
|
|
}
|
|
|
|
if (n)
|
|
spin_unlock(&n->list_lock);
|
|
|
|
while (discard_page) {
|
|
page = discard_page;
|
|
discard_page = discard_page->next;
|
|
|
|
stat(s, DEACTIVATE_EMPTY);
|
|
discard_slab(s, page);
|
|
stat(s, FREE_SLAB);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Put a page that was just frozen (in __slab_free) into a partial page
|
|
* slot if available. This is done without interrupts disabled and without
|
|
* preemption disabled. The cmpxchg is racy and may put the partial page
|
|
* onto a random cpus partial slot.
|
|
*
|
|
* If we did not find a slot then simply move all the partials to the
|
|
* per node partial list.
|
|
*/
|
|
int put_cpu_partial(struct kmem_cache *s, struct page *page, int drain)
|
|
{
|
|
struct page *oldpage;
|
|
int pages;
|
|
int pobjects;
|
|
|
|
do {
|
|
pages = 0;
|
|
pobjects = 0;
|
|
oldpage = this_cpu_read(s->cpu_slab->partial);
|
|
|
|
if (oldpage) {
|
|
pobjects = oldpage->pobjects;
|
|
pages = oldpage->pages;
|
|
if (drain && pobjects > s->cpu_partial) {
|
|
unsigned long flags;
|
|
/*
|
|
* partial array is full. Move the existing
|
|
* set to the per node partial list.
|
|
*/
|
|
local_irq_save(flags);
|
|
unfreeze_partials(s);
|
|
local_irq_restore(flags);
|
|
pobjects = 0;
|
|
pages = 0;
|
|
}
|
|
}
|
|
|
|
pages++;
|
|
pobjects += page->objects - page->inuse;
|
|
|
|
page->pages = pages;
|
|
page->pobjects = pobjects;
|
|
page->next = oldpage;
|
|
|
|
} while (this_cpu_cmpxchg(s->cpu_slab->partial, oldpage, page) != oldpage);
|
|
stat(s, CPU_PARTIAL_FREE);
|
|
return pobjects;
|
|
}
|
|
|
|
static inline void flush_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
|
|
{
|
|
stat(s, CPUSLAB_FLUSH);
|
|
deactivate_slab(s, c);
|
|
}
|
|
|
|
/*
|
|
* Flush cpu slab.
|
|
*
|
|
* Called from IPI handler with interrupts disabled.
|
|
*/
|
|
static inline void __flush_cpu_slab(struct kmem_cache *s, int cpu)
|
|
{
|
|
struct kmem_cache_cpu *c = per_cpu_ptr(s->cpu_slab, cpu);
|
|
|
|
if (likely(c)) {
|
|
if (c->page)
|
|
flush_slab(s, c);
|
|
|
|
unfreeze_partials(s);
|
|
}
|
|
}
|
|
|
|
static void flush_cpu_slab(void *d)
|
|
{
|
|
struct kmem_cache *s = d;
|
|
|
|
__flush_cpu_slab(s, smp_processor_id());
|
|
}
|
|
|
|
static void flush_all(struct kmem_cache *s)
|
|
{
|
|
on_each_cpu(flush_cpu_slab, s, 1);
|
|
}
|
|
|
|
/*
|
|
* Check if the objects in a per cpu structure fit numa
|
|
* locality expectations.
|
|
*/
|
|
static inline int node_match(struct kmem_cache_cpu *c, int node)
|
|
{
|
|
#ifdef CONFIG_NUMA
|
|
if (node != NUMA_NO_NODE && c->node != node)
|
|
return 0;
|
|
#endif
|
|
return 1;
|
|
}
|
|
|
|
static int count_free(struct page *page)
|
|
{
|
|
return page->objects - page->inuse;
|
|
}
|
|
|
|
static unsigned long count_partial(struct kmem_cache_node *n,
|
|
int (*get_count)(struct page *))
|
|
{
|
|
unsigned long flags;
|
|
unsigned long x = 0;
|
|
struct page *page;
|
|
|
|
spin_lock_irqsave(&n->list_lock, flags);
|
|
list_for_each_entry(page, &n->partial, lru)
|
|
x += get_count(page);
|
|
spin_unlock_irqrestore(&n->list_lock, flags);
|
|
return x;
|
|
}
|
|
|
|
static inline unsigned long node_nr_objs(struct kmem_cache_node *n)
|
|
{
|
|
#ifdef CONFIG_SLUB_DEBUG
|
|
return atomic_long_read(&n->total_objects);
|
|
#else
|
|
return 0;
|
|
#endif
|
|
}
|
|
|
|
static noinline void
|
|
slab_out_of_memory(struct kmem_cache *s, gfp_t gfpflags, int nid)
|
|
{
|
|
int node;
|
|
|
|
printk(KERN_WARNING
|
|
"SLUB: Unable to allocate memory on node %d (gfp=0x%x)\n",
|
|
nid, gfpflags);
|
|
printk(KERN_WARNING " cache: %s, object size: %d, buffer size: %d, "
|
|
"default order: %d, min order: %d\n", s->name, s->objsize,
|
|
s->size, oo_order(s->oo), oo_order(s->min));
|
|
|
|
if (oo_order(s->min) > get_order(s->objsize))
|
|
printk(KERN_WARNING " %s debugging increased min order, use "
|
|
"slub_debug=O to disable.\n", s->name);
|
|
|
|
for_each_online_node(node) {
|
|
struct kmem_cache_node *n = get_node(s, node);
|
|
unsigned long nr_slabs;
|
|
unsigned long nr_objs;
|
|
unsigned long nr_free;
|
|
|
|
if (!n)
|
|
continue;
|
|
|
|
nr_free = count_partial(n, count_free);
|
|
nr_slabs = node_nr_slabs(n);
|
|
nr_objs = node_nr_objs(n);
|
|
|
|
printk(KERN_WARNING
|
|
" node %d: slabs: %ld, objs: %ld, free: %ld\n",
|
|
node, nr_slabs, nr_objs, nr_free);
|
|
}
|
|
}
|
|
|
|
static inline void *new_slab_objects(struct kmem_cache *s, gfp_t flags,
|
|
int node, struct kmem_cache_cpu **pc)
|
|
{
|
|
void *object;
|
|
struct kmem_cache_cpu *c;
|
|
struct page *page = new_slab(s, flags, node);
|
|
|
|
if (page) {
|
|
c = __this_cpu_ptr(s->cpu_slab);
|
|
if (c->page)
|
|
flush_slab(s, c);
|
|
|
|
/*
|
|
* No other reference to the page yet so we can
|
|
* muck around with it freely without cmpxchg
|
|
*/
|
|
object = page->freelist;
|
|
page->freelist = NULL;
|
|
|
|
stat(s, ALLOC_SLAB);
|
|
c->node = page_to_nid(page);
|
|
c->page = page;
|
|
*pc = c;
|
|
} else
|
|
object = NULL;
|
|
|
|
return object;
|
|
}
|
|
|
|
/*
|
|
* Check the page->freelist of a page and either transfer the freelist to the per cpu freelist
|
|
* or deactivate the page.
|
|
*
|
|
* The page is still frozen if the return value is not NULL.
|
|
*
|
|
* If this function returns NULL then the page has been unfrozen.
|
|
*/
|
|
static inline void *get_freelist(struct kmem_cache *s, struct page *page)
|
|
{
|
|
struct page new;
|
|
unsigned long counters;
|
|
void *freelist;
|
|
|
|
do {
|
|
freelist = page->freelist;
|
|
counters = page->counters;
|
|
new.counters = counters;
|
|
VM_BUG_ON(!new.frozen);
|
|
|
|
new.inuse = page->objects;
|
|
new.frozen = freelist != NULL;
|
|
|
|
} while (!cmpxchg_double_slab(s, page,
|
|
freelist, counters,
|
|
NULL, new.counters,
|
|
"get_freelist"));
|
|
|
|
return freelist;
|
|
}
|
|
|
|
/*
|
|
* Slow path. The lockless freelist is empty or we need to perform
|
|
* debugging duties.
|
|
*
|
|
* Processing is still very fast if new objects have been freed to the
|
|
* regular freelist. In that case we simply take over the regular freelist
|
|
* as the lockless freelist and zap the regular freelist.
|
|
*
|
|
* If that is not working then we fall back to the partial lists. We take the
|
|
* first element of the freelist as the object to allocate now and move the
|
|
* rest of the freelist to the lockless freelist.
|
|
*
|
|
* And if we were unable to get a new slab from the partial slab lists then
|
|
* we need to allocate a new slab. This is the slowest path since it involves
|
|
* a call to the page allocator and the setup of a new slab.
|
|
*/
|
|
static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
|
|
unsigned long addr, struct kmem_cache_cpu *c)
|
|
{
|
|
void **object;
|
|
unsigned long flags;
|
|
|
|
local_irq_save(flags);
|
|
#ifdef CONFIG_PREEMPT
|
|
/*
|
|
* We may have been preempted and rescheduled on a different
|
|
* cpu before disabling interrupts. Need to reload cpu area
|
|
* pointer.
|
|
*/
|
|
c = this_cpu_ptr(s->cpu_slab);
|
|
#endif
|
|
|
|
if (!c->page)
|
|
goto new_slab;
|
|
redo:
|
|
if (unlikely(!node_match(c, node))) {
|
|
stat(s, ALLOC_NODE_MISMATCH);
|
|
deactivate_slab(s, c);
|
|
goto new_slab;
|
|
}
|
|
|
|
/* must check again c->freelist in case of cpu migration or IRQ */
|
|
object = c->freelist;
|
|
if (object)
|
|
goto load_freelist;
|
|
|
|
stat(s, ALLOC_SLOWPATH);
|
|
|
|
object = get_freelist(s, c->page);
|
|
|
|
if (!object) {
|
|
c->page = NULL;
|
|
stat(s, DEACTIVATE_BYPASS);
|
|
goto new_slab;
|
|
}
|
|
|
|
stat(s, ALLOC_REFILL);
|
|
|
|
load_freelist:
|
|
c->freelist = get_freepointer(s, object);
|
|
c->tid = next_tid(c->tid);
|
|
local_irq_restore(flags);
|
|
return object;
|
|
|
|
new_slab:
|
|
|
|
if (c->partial) {
|
|
c->page = c->partial;
|
|
c->partial = c->page->next;
|
|
c->node = page_to_nid(c->page);
|
|
stat(s, CPU_PARTIAL_ALLOC);
|
|
c->freelist = NULL;
|
|
goto redo;
|
|
}
|
|
|
|
/* Then do expensive stuff like retrieving pages from the partial lists */
|
|
object = get_partial(s, gfpflags, node, c);
|
|
|
|
if (unlikely(!object)) {
|
|
|
|
object = new_slab_objects(s, gfpflags, node, &c);
|
|
|
|
if (unlikely(!object)) {
|
|
if (!(gfpflags & __GFP_NOWARN) && printk_ratelimit())
|
|
slab_out_of_memory(s, gfpflags, node);
|
|
|
|
local_irq_restore(flags);
|
|
return NULL;
|
|
}
|
|
}
|
|
|
|
if (likely(!kmem_cache_debug(s)))
|
|
goto load_freelist;
|
|
|
|
/* Only entered in the debug case */
|
|
if (!alloc_debug_processing(s, c->page, object, addr))
|
|
goto new_slab; /* Slab failed checks. Next slab needed */
|
|
|
|
c->freelist = get_freepointer(s, object);
|
|
deactivate_slab(s, c);
|
|
c->node = NUMA_NO_NODE;
|
|
local_irq_restore(flags);
|
|
return object;
|
|
}
|
|
|
|
/*
|
|
* Inlined fastpath so that allocation functions (kmalloc, kmem_cache_alloc)
|
|
* have the fastpath folded into their functions. So no function call
|
|
* overhead for requests that can be satisfied on the fastpath.
|
|
*
|
|
* The fastpath works by first checking if the lockless freelist can be used.
|
|
* If not then __slab_alloc is called for slow processing.
|
|
*
|
|
* Otherwise we can simply pick the next object from the lockless free list.
|
|
*/
|
|
static __always_inline void *slab_alloc(struct kmem_cache *s,
|
|
gfp_t gfpflags, int node, unsigned long addr)
|
|
{
|
|
void **object;
|
|
struct kmem_cache_cpu *c;
|
|
unsigned long tid;
|
|
|
|
if (slab_pre_alloc_hook(s, gfpflags))
|
|
return NULL;
|
|
|
|
redo:
|
|
|
|
/*
|
|
* Must read kmem_cache cpu data via this cpu ptr. Preemption is
|
|
* enabled. We may switch back and forth between cpus while
|
|
* reading from one cpu area. That does not matter as long
|
|
* as we end up on the original cpu again when doing the cmpxchg.
|
|
*/
|
|
c = __this_cpu_ptr(s->cpu_slab);
|
|
|
|
/*
|
|
* The transaction ids are globally unique per cpu and per operation on
|
|
* a per cpu queue. Thus they can be guarantee that the cmpxchg_double
|
|
* occurs on the right processor and that there was no operation on the
|
|
* linked list in between.
|
|
*/
|
|
tid = c->tid;
|
|
barrier();
|
|
|
|
object = c->freelist;
|
|
if (unlikely(!object || !node_match(c, node)))
|
|
|
|
object = __slab_alloc(s, gfpflags, node, addr, c);
|
|
|
|
else {
|
|
/*
|
|
* The cmpxchg will only match if there was no additional
|
|
* operation and if we are on the right processor.
|
|
*
|
|
* The cmpxchg does the following atomically (without lock semantics!)
|
|
* 1. Relocate first pointer to the current per cpu area.
|
|
* 2. Verify that tid and freelist have not been changed
|
|
* 3. If they were not changed replace tid and freelist
|
|
*
|
|
* Since this is without lock semantics the protection is only against
|
|
* code executing on this cpu *not* from access by other cpus.
|
|
*/
|
|
if (unlikely(!this_cpu_cmpxchg_double(
|
|
s->cpu_slab->freelist, s->cpu_slab->tid,
|
|
object, tid,
|
|
get_freepointer_safe(s, object), next_tid(tid)))) {
|
|
|
|
note_cmpxchg_failure("slab_alloc", s, tid);
|
|
goto redo;
|
|
}
|
|
stat(s, ALLOC_FASTPATH);
|
|
}
|
|
|
|
if (unlikely(gfpflags & __GFP_ZERO) && object)
|
|
memset(object, 0, s->objsize);
|
|
|
|
slab_post_alloc_hook(s, gfpflags, object);
|
|
|
|
return object;
|
|
}
|
|
|
|
void *kmem_cache_alloc(struct kmem_cache *s, gfp_t gfpflags)
|
|
{
|
|
void *ret = slab_alloc(s, gfpflags, NUMA_NO_NODE, _RET_IP_);
|
|
|
|
trace_kmem_cache_alloc(_RET_IP_, ret, s->objsize, s->size, gfpflags);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_alloc);
|
|
|
|
#ifdef CONFIG_TRACING
|
|
void *kmem_cache_alloc_trace(struct kmem_cache *s, gfp_t gfpflags, size_t size)
|
|
{
|
|
void *ret = slab_alloc(s, gfpflags, NUMA_NO_NODE, _RET_IP_);
|
|
trace_kmalloc(_RET_IP_, ret, size, s->size, gfpflags);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_alloc_trace);
|
|
|
|
void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order)
|
|
{
|
|
void *ret = kmalloc_order(size, flags, order);
|
|
trace_kmalloc(_RET_IP_, ret, size, PAGE_SIZE << order, flags);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(kmalloc_order_trace);
|
|
#endif
|
|
|
|
#ifdef CONFIG_NUMA
|
|
void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t gfpflags, int node)
|
|
{
|
|
void *ret = slab_alloc(s, gfpflags, node, _RET_IP_);
|
|
|
|
trace_kmem_cache_alloc_node(_RET_IP_, ret,
|
|
s->objsize, s->size, gfpflags, node);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_alloc_node);
|
|
|
|
#ifdef CONFIG_TRACING
|
|
void *kmem_cache_alloc_node_trace(struct kmem_cache *s,
|
|
gfp_t gfpflags,
|
|
int node, size_t size)
|
|
{
|
|
void *ret = slab_alloc(s, gfpflags, node, _RET_IP_);
|
|
|
|
trace_kmalloc_node(_RET_IP_, ret,
|
|
size, s->size, gfpflags, node);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_alloc_node_trace);
|
|
#endif
|
|
#endif
|
|
|
|
/*
|
|
* Slow patch handling. This may still be called frequently since objects
|
|
* have a longer lifetime than the cpu slabs in most processing loads.
|
|
*
|
|
* So we still attempt to reduce cache line usage. Just take the slab
|
|
* lock and free the item. If there is no additional partial page
|
|
* handling required then we can return immediately.
|
|
*/
|
|
static void __slab_free(struct kmem_cache *s, struct page *page,
|
|
void *x, unsigned long addr)
|
|
{
|
|
void *prior;
|
|
void **object = (void *)x;
|
|
int was_frozen;
|
|
int inuse;
|
|
struct page new;
|
|
unsigned long counters;
|
|
struct kmem_cache_node *n = NULL;
|
|
unsigned long uninitialized_var(flags);
|
|
|
|
stat(s, FREE_SLOWPATH);
|
|
|
|
if (kmem_cache_debug(s) && !free_debug_processing(s, page, x, addr))
|
|
return;
|
|
|
|
do {
|
|
prior = page->freelist;
|
|
counters = page->counters;
|
|
set_freepointer(s, object, prior);
|
|
new.counters = counters;
|
|
was_frozen = new.frozen;
|
|
new.inuse--;
|
|
if ((!new.inuse || !prior) && !was_frozen && !n) {
|
|
|
|
if (!kmem_cache_debug(s) && !prior)
|
|
|
|
/*
|
|
* Slab was on no list before and will be partially empty
|
|
* We can defer the list move and instead freeze it.
|
|
*/
|
|
new.frozen = 1;
|
|
|
|
else { /* Needs to be taken off a list */
|
|
|
|
n = get_node(s, page_to_nid(page));
|
|
/*
|
|
* Speculatively acquire the list_lock.
|
|
* If the cmpxchg does not succeed then we may
|
|
* drop the list_lock without any processing.
|
|
*
|
|
* Otherwise the list_lock will synchronize with
|
|
* other processors updating the list of slabs.
|
|
*/
|
|
spin_lock_irqsave(&n->list_lock, flags);
|
|
|
|
}
|
|
}
|
|
inuse = new.inuse;
|
|
|
|
} while (!cmpxchg_double_slab(s, page,
|
|
prior, counters,
|
|
object, new.counters,
|
|
"__slab_free"));
|
|
|
|
if (likely(!n)) {
|
|
|
|
/*
|
|
* If we just froze the page then put it onto the
|
|
* per cpu partial list.
|
|
*/
|
|
if (new.frozen && !was_frozen)
|
|
put_cpu_partial(s, page, 1);
|
|
|
|
/*
|
|
* The list lock was not taken therefore no list
|
|
* activity can be necessary.
|
|
*/
|
|
if (was_frozen)
|
|
stat(s, FREE_FROZEN);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* was_frozen may have been set after we acquired the list_lock in
|
|
* an earlier loop. So we need to check it here again.
|
|
*/
|
|
if (was_frozen)
|
|
stat(s, FREE_FROZEN);
|
|
else {
|
|
if (unlikely(!inuse && n->nr_partial > s->min_partial))
|
|
goto slab_empty;
|
|
|
|
/*
|
|
* Objects left in the slab. If it was not on the partial list before
|
|
* then add it.
|
|
*/
|
|
if (unlikely(!prior)) {
|
|
remove_full(s, page);
|
|
add_partial(n, page, DEACTIVATE_TO_TAIL);
|
|
stat(s, FREE_ADD_PARTIAL);
|
|
}
|
|
}
|
|
spin_unlock_irqrestore(&n->list_lock, flags);
|
|
return;
|
|
|
|
slab_empty:
|
|
if (prior) {
|
|
/*
|
|
* Slab on the partial list.
|
|
*/
|
|
remove_partial(n, page);
|
|
stat(s, FREE_REMOVE_PARTIAL);
|
|
} else
|
|
/* Slab must be on the full list */
|
|
remove_full(s, page);
|
|
|
|
spin_unlock_irqrestore(&n->list_lock, flags);
|
|
stat(s, FREE_SLAB);
|
|
discard_slab(s, page);
|
|
}
|
|
|
|
/*
|
|
* Fastpath with forced inlining to produce a kfree and kmem_cache_free that
|
|
* can perform fastpath freeing without additional function calls.
|
|
*
|
|
* The fastpath is only possible if we are freeing to the current cpu slab
|
|
* of this processor. This typically the case if we have just allocated
|
|
* the item before.
|
|
*
|
|
* If fastpath is not possible then fall back to __slab_free where we deal
|
|
* with all sorts of special processing.
|
|
*/
|
|
static __always_inline void slab_free(struct kmem_cache *s,
|
|
struct page *page, void *x, unsigned long addr)
|
|
{
|
|
void **object = (void *)x;
|
|
struct kmem_cache_cpu *c;
|
|
unsigned long tid;
|
|
|
|
slab_free_hook(s, x);
|
|
|
|
redo:
|
|
/*
|
|
* Determine the currently cpus per cpu slab.
|
|
* The cpu may change afterward. However that does not matter since
|
|
* data is retrieved via this pointer. If we are on the same cpu
|
|
* during the cmpxchg then the free will succedd.
|
|
*/
|
|
c = __this_cpu_ptr(s->cpu_slab);
|
|
|
|
tid = c->tid;
|
|
barrier();
|
|
|
|
if (likely(page == c->page)) {
|
|
set_freepointer(s, object, c->freelist);
|
|
|
|
if (unlikely(!this_cpu_cmpxchg_double(
|
|
s->cpu_slab->freelist, s->cpu_slab->tid,
|
|
c->freelist, tid,
|
|
object, next_tid(tid)))) {
|
|
|
|
note_cmpxchg_failure("slab_free", s, tid);
|
|
goto redo;
|
|
}
|
|
stat(s, FREE_FASTPATH);
|
|
} else
|
|
__slab_free(s, page, x, addr);
|
|
|
|
}
|
|
|
|
void kmem_cache_free(struct kmem_cache *s, void *x)
|
|
{
|
|
struct page *page;
|
|
|
|
page = virt_to_head_page(x);
|
|
|
|
slab_free(s, page, x, _RET_IP_);
|
|
|
|
trace_kmem_cache_free(_RET_IP_, x);
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_free);
|
|
|
|
/*
|
|
* Object placement in a slab is made very easy because we always start at
|
|
* offset 0. If we tune the size of the object to the alignment then we can
|
|
* get the required alignment by putting one properly sized object after
|
|
* another.
|
|
*
|
|
* Notice that the allocation order determines the sizes of the per cpu
|
|
* caches. Each processor has always one slab available for allocations.
|
|
* Increasing the allocation order reduces the number of times that slabs
|
|
* must be moved on and off the partial lists and is therefore a factor in
|
|
* locking overhead.
|
|
*/
|
|
|
|
/*
|
|
* Mininum / Maximum order of slab pages. This influences locking overhead
|
|
* and slab fragmentation. A higher order reduces the number of partial slabs
|
|
* and increases the number of allocations possible without having to
|
|
* take the list_lock.
|
|
*/
|
|
static int slub_min_order;
|
|
static int slub_max_order = PAGE_ALLOC_COSTLY_ORDER;
|
|
static int slub_min_objects;
|
|
|
|
/*
|
|
* Merge control. If this is set then no merging of slab caches will occur.
|
|
* (Could be removed. This was introduced to pacify the merge skeptics.)
|
|
*/
|
|
static int slub_nomerge;
|
|
|
|
/*
|
|
* Calculate the order of allocation given an slab object size.
|
|
*
|
|
* The order of allocation has significant impact on performance and other
|
|
* system components. Generally order 0 allocations should be preferred since
|
|
* order 0 does not cause fragmentation in the page allocator. Larger objects
|
|
* be problematic to put into order 0 slabs because there may be too much
|
|
* unused space left. We go to a higher order if more than 1/16th of the slab
|
|
* would be wasted.
|
|
*
|
|
* In order to reach satisfactory performance we must ensure that a minimum
|
|
* number of objects is in one slab. Otherwise we may generate too much
|
|
* activity on the partial lists which requires taking the list_lock. This is
|
|
* less a concern for large slabs though which are rarely used.
|
|
*
|
|
* slub_max_order specifies the order where we begin to stop considering the
|
|
* number of objects in a slab as critical. If we reach slub_max_order then
|
|
* we try to keep the page order as low as possible. So we accept more waste
|
|
* of space in favor of a small page order.
|
|
*
|
|
* Higher order allocations also allow the placement of more objects in a
|
|
* slab and thereby reduce object handling overhead. If the user has
|
|
* requested a higher mininum order then we start with that one instead of
|
|
* the smallest order which will fit the object.
|
|
*/
|
|
static inline int slab_order(int size, int min_objects,
|
|
int max_order, int fract_leftover, int reserved)
|
|
{
|
|
int order;
|
|
int rem;
|
|
int min_order = slub_min_order;
|
|
|
|
if (order_objects(min_order, size, reserved) > MAX_OBJS_PER_PAGE)
|
|
return get_order(size * MAX_OBJS_PER_PAGE) - 1;
|
|
|
|
for (order = max(min_order,
|
|
fls(min_objects * size - 1) - PAGE_SHIFT);
|
|
order <= max_order; order++) {
|
|
|
|
unsigned long slab_size = PAGE_SIZE << order;
|
|
|
|
if (slab_size < min_objects * size + reserved)
|
|
continue;
|
|
|
|
rem = (slab_size - reserved) % size;
|
|
|
|
if (rem <= slab_size / fract_leftover)
|
|
break;
|
|
|
|
}
|
|
|
|
return order;
|
|
}
|
|
|
|
static inline int calculate_order(int size, int reserved)
|
|
{
|
|
int order;
|
|
int min_objects;
|
|
int fraction;
|
|
int max_objects;
|
|
|
|
/*
|
|
* Attempt to find best configuration for a slab. This
|
|
* works by first attempting to generate a layout with
|
|
* the best configuration and backing off gradually.
|
|
*
|
|
* First we reduce the acceptable waste in a slab. Then
|
|
* we reduce the minimum objects required in a slab.
|
|
*/
|
|
min_objects = slub_min_objects;
|
|
if (!min_objects)
|
|
min_objects = 4 * (fls(nr_cpu_ids) + 1);
|
|
max_objects = order_objects(slub_max_order, size, reserved);
|
|
min_objects = min(min_objects, max_objects);
|
|
|
|
while (min_objects > 1) {
|
|
fraction = 16;
|
|
while (fraction >= 4) {
|
|
order = slab_order(size, min_objects,
|
|
slub_max_order, fraction, reserved);
|
|
if (order <= slub_max_order)
|
|
return order;
|
|
fraction /= 2;
|
|
}
|
|
min_objects--;
|
|
}
|
|
|
|
/*
|
|
* We were unable to place multiple objects in a slab. Now
|
|
* lets see if we can place a single object there.
|
|
*/
|
|
order = slab_order(size, 1, slub_max_order, 1, reserved);
|
|
if (order <= slub_max_order)
|
|
return order;
|
|
|
|
/*
|
|
* Doh this slab cannot be placed using slub_max_order.
|
|
*/
|
|
order = slab_order(size, 1, MAX_ORDER, 1, reserved);
|
|
if (order < MAX_ORDER)
|
|
return order;
|
|
return -ENOSYS;
|
|
}
|
|
|
|
/*
|
|
* Figure out what the alignment of the objects will be.
|
|
*/
|
|
static unsigned long calculate_alignment(unsigned long flags,
|
|
unsigned long align, unsigned long size)
|
|
{
|
|
/*
|
|
* If the user wants hardware cache aligned objects then follow that
|
|
* suggestion if the object is sufficiently large.
|
|
*
|
|
* The hardware cache alignment cannot override the specified
|
|
* alignment though. If that is greater then use it.
|
|
*/
|
|
if (flags & SLAB_HWCACHE_ALIGN) {
|
|
unsigned long ralign = cache_line_size();
|
|
while (size <= ralign / 2)
|
|
ralign /= 2;
|
|
align = max(align, ralign);
|
|
}
|
|
|
|
if (align < ARCH_SLAB_MINALIGN)
|
|
align = ARCH_SLAB_MINALIGN;
|
|
|
|
return ALIGN(align, sizeof(void *));
|
|
}
|
|
|
|
static void
|
|
init_kmem_cache_node(struct kmem_cache_node *n, struct kmem_cache *s)
|
|
{
|
|
n->nr_partial = 0;
|
|
spin_lock_init(&n->list_lock);
|
|
INIT_LIST_HEAD(&n->partial);
|
|
#ifdef CONFIG_SLUB_DEBUG
|
|
atomic_long_set(&n->nr_slabs, 0);
|
|
atomic_long_set(&n->total_objects, 0);
|
|
INIT_LIST_HEAD(&n->full);
|
|
#endif
|
|
}
|
|
|
|
static inline int alloc_kmem_cache_cpus(struct kmem_cache *s)
|
|
{
|
|
BUILD_BUG_ON(PERCPU_DYNAMIC_EARLY_SIZE <
|
|
SLUB_PAGE_SHIFT * sizeof(struct kmem_cache_cpu));
|
|
|
|
/*
|
|
* Must align to double word boundary for the double cmpxchg
|
|
* instructions to work; see __pcpu_double_call_return_bool().
|
|
*/
|
|
s->cpu_slab = __alloc_percpu(sizeof(struct kmem_cache_cpu),
|
|
2 * sizeof(void *));
|
|
|
|
if (!s->cpu_slab)
|
|
return 0;
|
|
|
|
init_kmem_cache_cpus(s);
|
|
|
|
return 1;
|
|
}
|
|
|
|
static struct kmem_cache *kmem_cache_node;
|
|
|
|
/*
|
|
* No kmalloc_node yet so do it by hand. We know that this is the first
|
|
* slab on the node for this slabcache. There are no concurrent accesses
|
|
* possible.
|
|
*
|
|
* Note that this function only works on the kmalloc_node_cache
|
|
* when allocating for the kmalloc_node_cache. This is used for bootstrapping
|
|
* memory on a fresh node that has no slab structures yet.
|
|
*/
|
|
static void early_kmem_cache_node_alloc(int node)
|
|
{
|
|
struct page *page;
|
|
struct kmem_cache_node *n;
|
|
|
|
BUG_ON(kmem_cache_node->size < sizeof(struct kmem_cache_node));
|
|
|
|
page = new_slab(kmem_cache_node, GFP_NOWAIT, node);
|
|
|
|
BUG_ON(!page);
|
|
if (page_to_nid(page) != node) {
|
|
printk(KERN_ERR "SLUB: Unable to allocate memory from "
|
|
"node %d\n", node);
|
|
printk(KERN_ERR "SLUB: Allocating a useless per node structure "
|
|
"in order to be able to continue\n");
|
|
}
|
|
|
|
n = page->freelist;
|
|
BUG_ON(!n);
|
|
page->freelist = get_freepointer(kmem_cache_node, n);
|
|
page->inuse = 1;
|
|
page->frozen = 0;
|
|
kmem_cache_node->node[node] = n;
|
|
#ifdef CONFIG_SLUB_DEBUG
|
|
init_object(kmem_cache_node, n, SLUB_RED_ACTIVE);
|
|
init_tracking(kmem_cache_node, n);
|
|
#endif
|
|
init_kmem_cache_node(n, kmem_cache_node);
|
|
inc_slabs_node(kmem_cache_node, node, page->objects);
|
|
|
|
add_partial(n, page, DEACTIVATE_TO_HEAD);
|
|
}
|
|
|
|
static void free_kmem_cache_nodes(struct kmem_cache *s)
|
|
{
|
|
int node;
|
|
|
|
for_each_node_state(node, N_NORMAL_MEMORY) {
|
|
struct kmem_cache_node *n = s->node[node];
|
|
|
|
if (n)
|
|
kmem_cache_free(kmem_cache_node, n);
|
|
|
|
s->node[node] = NULL;
|
|
}
|
|
}
|
|
|
|
static int init_kmem_cache_nodes(struct kmem_cache *s)
|
|
{
|
|
int node;
|
|
|
|
for_each_node_state(node, N_NORMAL_MEMORY) {
|
|
struct kmem_cache_node *n;
|
|
|
|
if (slab_state == DOWN) {
|
|
early_kmem_cache_node_alloc(node);
|
|
continue;
|
|
}
|
|
n = kmem_cache_alloc_node(kmem_cache_node,
|
|
GFP_KERNEL, node);
|
|
|
|
if (!n) {
|
|
free_kmem_cache_nodes(s);
|
|
return 0;
|
|
}
|
|
|
|
s->node[node] = n;
|
|
init_kmem_cache_node(n, s);
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
static void set_min_partial(struct kmem_cache *s, unsigned long min)
|
|
{
|
|
if (min < MIN_PARTIAL)
|
|
min = MIN_PARTIAL;
|
|
else if (min > MAX_PARTIAL)
|
|
min = MAX_PARTIAL;
|
|
s->min_partial = min;
|
|
}
|
|
|
|
/*
|
|
* calculate_sizes() determines the order and the distribution of data within
|
|
* a slab object.
|
|
*/
|
|
static int calculate_sizes(struct kmem_cache *s, int forced_order)
|
|
{
|
|
unsigned long flags = s->flags;
|
|
unsigned long size = s->objsize;
|
|
unsigned long align = s->align;
|
|
int order;
|
|
|
|
/*
|
|
* Round up object size to the next word boundary. We can only
|
|
* place the free pointer at word boundaries and this determines
|
|
* the possible location of the free pointer.
|
|
*/
|
|
size = ALIGN(size, sizeof(void *));
|
|
|
|
#ifdef CONFIG_SLUB_DEBUG
|
|
/*
|
|
* Determine if we can poison the object itself. If the user of
|
|
* the slab may touch the object after free or before allocation
|
|
* then we should never poison the object itself.
|
|
*/
|
|
if ((flags & SLAB_POISON) && !(flags & SLAB_DESTROY_BY_RCU) &&
|
|
!s->ctor)
|
|
s->flags |= __OBJECT_POISON;
|
|
else
|
|
s->flags &= ~__OBJECT_POISON;
|
|
|
|
|
|
/*
|
|
* If we are Redzoning then check if there is some space between the
|
|
* end of the object and the free pointer. If not then add an
|
|
* additional word to have some bytes to store Redzone information.
|
|
*/
|
|
if ((flags & SLAB_RED_ZONE) && size == s->objsize)
|
|
size += sizeof(void *);
|
|
#endif
|
|
|
|
/*
|
|
* With that we have determined the number of bytes in actual use
|
|
* by the object. This is the potential offset to the free pointer.
|
|
*/
|
|
s->inuse = size;
|
|
|
|
if (((flags & (SLAB_DESTROY_BY_RCU | SLAB_POISON)) ||
|
|
s->ctor)) {
|
|
/*
|
|
* Relocate free pointer after the object if it is not
|
|
* permitted to overwrite the first word of the object on
|
|
* kmem_cache_free.
|
|
*
|
|
* This is the case if we do RCU, have a constructor or
|
|
* destructor or are poisoning the objects.
|
|
*/
|
|
s->offset = size;
|
|
size += sizeof(void *);
|
|
}
|
|
|
|
#ifdef CONFIG_SLUB_DEBUG
|
|
if (flags & SLAB_STORE_USER)
|
|
/*
|
|
* Need to store information about allocs and frees after
|
|
* the object.
|
|
*/
|
|
size += 2 * sizeof(struct track);
|
|
|
|
if (flags & SLAB_RED_ZONE)
|
|
/*
|
|
* Add some empty padding so that we can catch
|
|
* overwrites from earlier objects rather than let
|
|
* tracking information or the free pointer be
|
|
* corrupted if a user writes before the start
|
|
* of the object.
|
|
*/
|
|
size += sizeof(void *);
|
|
#endif
|
|
|
|
/*
|
|
* Determine the alignment based on various parameters that the
|
|
* user specified and the dynamic determination of cache line size
|
|
* on bootup.
|
|
*/
|
|
align = calculate_alignment(flags, align, s->objsize);
|
|
s->align = align;
|
|
|
|
/*
|
|
* SLUB stores one object immediately after another beginning from
|
|
* offset 0. In order to align the objects we have to simply size
|
|
* each object to conform to the alignment.
|
|
*/
|
|
size = ALIGN(size, align);
|
|
s->size = size;
|
|
if (forced_order >= 0)
|
|
order = forced_order;
|
|
else
|
|
order = calculate_order(size, s->reserved);
|
|
|
|
if (order < 0)
|
|
return 0;
|
|
|
|
s->allocflags = 0;
|
|
if (order)
|
|
s->allocflags |= __GFP_COMP;
|
|
|
|
if (s->flags & SLAB_CACHE_DMA)
|
|
s->allocflags |= SLUB_DMA;
|
|
|
|
if (s->flags & SLAB_RECLAIM_ACCOUNT)
|
|
s->allocflags |= __GFP_RECLAIMABLE;
|
|
|
|
/*
|
|
* Determine the number of objects per slab
|
|
*/
|
|
s->oo = oo_make(order, size, s->reserved);
|
|
s->min = oo_make(get_order(size), size, s->reserved);
|
|
if (oo_objects(s->oo) > oo_objects(s->max))
|
|
s->max = s->oo;
|
|
|
|
return !!oo_objects(s->oo);
|
|
|
|
}
|
|
|
|
static int kmem_cache_open(struct kmem_cache *s,
|
|
const char *name, size_t size,
|
|
size_t align, unsigned long flags,
|
|
void (*ctor)(void *))
|
|
{
|
|
memset(s, 0, kmem_size);
|
|
s->name = name;
|
|
s->ctor = ctor;
|
|
s->objsize = size;
|
|
s->align = align;
|
|
s->flags = kmem_cache_flags(size, flags, name, ctor);
|
|
s->reserved = 0;
|
|
|
|
if (need_reserve_slab_rcu && (s->flags & SLAB_DESTROY_BY_RCU))
|
|
s->reserved = sizeof(struct rcu_head);
|
|
|
|
if (!calculate_sizes(s, -1))
|
|
goto error;
|
|
if (disable_higher_order_debug) {
|
|
/*
|
|
* Disable debugging flags that store metadata if the min slab
|
|
* order increased.
|
|
*/
|
|
if (get_order(s->size) > get_order(s->objsize)) {
|
|
s->flags &= ~DEBUG_METADATA_FLAGS;
|
|
s->offset = 0;
|
|
if (!calculate_sizes(s, -1))
|
|
goto error;
|
|
}
|
|
}
|
|
|
|
#ifdef CONFIG_CMPXCHG_DOUBLE
|
|
if (system_has_cmpxchg_double() && (s->flags & SLAB_DEBUG_FLAGS) == 0)
|
|
/* Enable fast mode */
|
|
s->flags |= __CMPXCHG_DOUBLE;
|
|
#endif
|
|
|
|
/*
|
|
* The larger the object size is, the more pages we want on the partial
|
|
* list to avoid pounding the page allocator excessively.
|
|
*/
|
|
set_min_partial(s, ilog2(s->size) / 2);
|
|
|
|
/*
|
|
* cpu_partial determined the maximum number of objects kept in the
|
|
* per cpu partial lists of a processor.
|
|
*
|
|
* Per cpu partial lists mainly contain slabs that just have one
|
|
* object freed. If they are used for allocation then they can be
|
|
* filled up again with minimal effort. The slab will never hit the
|
|
* per node partial lists and therefore no locking will be required.
|
|
*
|
|
* This setting also determines
|
|
*
|
|
* A) The number of objects from per cpu partial slabs dumped to the
|
|
* per node list when we reach the limit.
|
|
* B) The number of objects in cpu partial slabs to extract from the
|
|
* per node list when we run out of per cpu objects. We only fetch 50%
|
|
* to keep some capacity around for frees.
|
|
*/
|
|
if (kmem_cache_debug(s))
|
|
s->cpu_partial = 0;
|
|
else if (s->size >= PAGE_SIZE)
|
|
s->cpu_partial = 2;
|
|
else if (s->size >= 1024)
|
|
s->cpu_partial = 6;
|
|
else if (s->size >= 256)
|
|
s->cpu_partial = 13;
|
|
else
|
|
s->cpu_partial = 30;
|
|
|
|
s->refcount = 1;
|
|
#ifdef CONFIG_NUMA
|
|
s->remote_node_defrag_ratio = 1000;
|
|
#endif
|
|
if (!init_kmem_cache_nodes(s))
|
|
goto error;
|
|
|
|
if (alloc_kmem_cache_cpus(s))
|
|
return 1;
|
|
|
|
free_kmem_cache_nodes(s);
|
|
error:
|
|
if (flags & SLAB_PANIC)
|
|
panic("Cannot create slab %s size=%lu realsize=%u "
|
|
"order=%u offset=%u flags=%lx\n",
|
|
s->name, (unsigned long)size, s->size, oo_order(s->oo),
|
|
s->offset, flags);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Determine the size of a slab object
|
|
*/
|
|
unsigned int kmem_cache_size(struct kmem_cache *s)
|
|
{
|
|
return s->objsize;
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_size);
|
|
|
|
static void list_slab_objects(struct kmem_cache *s, struct page *page,
|
|
const char *text)
|
|
{
|
|
#ifdef CONFIG_SLUB_DEBUG
|
|
void *addr = page_address(page);
|
|
void *p;
|
|
unsigned long *map = kzalloc(BITS_TO_LONGS(page->objects) *
|
|
sizeof(long), GFP_ATOMIC);
|
|
if (!map)
|
|
return;
|
|
slab_err(s, page, "%s", text);
|
|
slab_lock(page);
|
|
|
|
get_map(s, page, map);
|
|
for_each_object(p, s, addr, page->objects) {
|
|
|
|
if (!test_bit(slab_index(p, s, addr), map)) {
|
|
printk(KERN_ERR "INFO: Object 0x%p @offset=%tu\n",
|
|
p, p - addr);
|
|
print_tracking(s, p);
|
|
}
|
|
}
|
|
slab_unlock(page);
|
|
kfree(map);
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* Attempt to free all partial slabs on a node.
|
|
* This is called from kmem_cache_close(). We must be the last thread
|
|
* using the cache and therefore we do not need to lock anymore.
|
|
*/
|
|
static void free_partial(struct kmem_cache *s, struct kmem_cache_node *n)
|
|
{
|
|
struct page *page, *h;
|
|
|
|
list_for_each_entry_safe(page, h, &n->partial, lru) {
|
|
if (!page->inuse) {
|
|
remove_partial(n, page);
|
|
discard_slab(s, page);
|
|
} else {
|
|
list_slab_objects(s, page,
|
|
"Objects remaining on kmem_cache_close()");
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Release all resources used by a slab cache.
|
|
*/
|
|
static inline int kmem_cache_close(struct kmem_cache *s)
|
|
{
|
|
int node;
|
|
|
|
flush_all(s);
|
|
free_percpu(s->cpu_slab);
|
|
/* Attempt to free all objects */
|
|
for_each_node_state(node, N_NORMAL_MEMORY) {
|
|
struct kmem_cache_node *n = get_node(s, node);
|
|
|
|
free_partial(s, n);
|
|
if (n->nr_partial || slabs_node(s, node))
|
|
return 1;
|
|
}
|
|
free_kmem_cache_nodes(s);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Close a cache and release the kmem_cache structure
|
|
* (must be used for caches created using kmem_cache_create)
|
|
*/
|
|
void kmem_cache_destroy(struct kmem_cache *s)
|
|
{
|
|
down_write(&slub_lock);
|
|
s->refcount--;
|
|
if (!s->refcount) {
|
|
list_del(&s->list);
|
|
up_write(&slub_lock);
|
|
if (kmem_cache_close(s)) {
|
|
printk(KERN_ERR "SLUB %s: %s called for cache that "
|
|
"still has objects.\n", s->name, __func__);
|
|
dump_stack();
|
|
}
|
|
if (s->flags & SLAB_DESTROY_BY_RCU)
|
|
rcu_barrier();
|
|
sysfs_slab_remove(s);
|
|
} else
|
|
up_write(&slub_lock);
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_destroy);
|
|
|
|
/********************************************************************
|
|
* Kmalloc subsystem
|
|
*******************************************************************/
|
|
|
|
struct kmem_cache *kmalloc_caches[SLUB_PAGE_SHIFT];
|
|
EXPORT_SYMBOL(kmalloc_caches);
|
|
|
|
static struct kmem_cache *kmem_cache;
|
|
|
|
#ifdef CONFIG_ZONE_DMA
|
|
static struct kmem_cache *kmalloc_dma_caches[SLUB_PAGE_SHIFT];
|
|
#endif
|
|
|
|
static int __init setup_slub_min_order(char *str)
|
|
{
|
|
get_option(&str, &slub_min_order);
|
|
|
|
return 1;
|
|
}
|
|
|
|
__setup("slub_min_order=", setup_slub_min_order);
|
|
|
|
static int __init setup_slub_max_order(char *str)
|
|
{
|
|
get_option(&str, &slub_max_order);
|
|
slub_max_order = min(slub_max_order, MAX_ORDER - 1);
|
|
|
|
return 1;
|
|
}
|
|
|
|
__setup("slub_max_order=", setup_slub_max_order);
|
|
|
|
static int __init setup_slub_min_objects(char *str)
|
|
{
|
|
get_option(&str, &slub_min_objects);
|
|
|
|
return 1;
|
|
}
|
|
|
|
__setup("slub_min_objects=", setup_slub_min_objects);
|
|
|
|
static int __init setup_slub_nomerge(char *str)
|
|
{
|
|
slub_nomerge = 1;
|
|
return 1;
|
|
}
|
|
|
|
__setup("slub_nomerge", setup_slub_nomerge);
|
|
|
|
static struct kmem_cache *__init create_kmalloc_cache(const char *name,
|
|
int size, unsigned int flags)
|
|
{
|
|
struct kmem_cache *s;
|
|
|
|
s = kmem_cache_alloc(kmem_cache, GFP_NOWAIT);
|
|
|
|
/*
|
|
* This function is called with IRQs disabled during early-boot on
|
|
* single CPU so there's no need to take slub_lock here.
|
|
*/
|
|
if (!kmem_cache_open(s, name, size, ARCH_KMALLOC_MINALIGN,
|
|
flags, NULL))
|
|
goto panic;
|
|
|
|
list_add(&s->list, &slab_caches);
|
|
return s;
|
|
|
|
panic:
|
|
panic("Creation of kmalloc slab %s size=%d failed.\n", name, size);
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* Conversion table for small slabs sizes / 8 to the index in the
|
|
* kmalloc array. This is necessary for slabs < 192 since we have non power
|
|
* of two cache sizes there. The size of larger slabs can be determined using
|
|
* fls.
|
|
*/
|
|
static s8 size_index[24] = {
|
|
3, /* 8 */
|
|
4, /* 16 */
|
|
5, /* 24 */
|
|
5, /* 32 */
|
|
6, /* 40 */
|
|
6, /* 48 */
|
|
6, /* 56 */
|
|
6, /* 64 */
|
|
1, /* 72 */
|
|
1, /* 80 */
|
|
1, /* 88 */
|
|
1, /* 96 */
|
|
7, /* 104 */
|
|
7, /* 112 */
|
|
7, /* 120 */
|
|
7, /* 128 */
|
|
2, /* 136 */
|
|
2, /* 144 */
|
|
2, /* 152 */
|
|
2, /* 160 */
|
|
2, /* 168 */
|
|
2, /* 176 */
|
|
2, /* 184 */
|
|
2 /* 192 */
|
|
};
|
|
|
|
static inline int size_index_elem(size_t bytes)
|
|
{
|
|
return (bytes - 1) / 8;
|
|
}
|
|
|
|
static struct kmem_cache *get_slab(size_t size, gfp_t flags)
|
|
{
|
|
int index;
|
|
|
|
if (size <= 192) {
|
|
if (!size)
|
|
return ZERO_SIZE_PTR;
|
|
|
|
index = size_index[size_index_elem(size)];
|
|
} else
|
|
index = fls(size - 1);
|
|
|
|
#ifdef CONFIG_ZONE_DMA
|
|
if (unlikely((flags & SLUB_DMA)))
|
|
return kmalloc_dma_caches[index];
|
|
|
|
#endif
|
|
return kmalloc_caches[index];
|
|
}
|
|
|
|
void *__kmalloc(size_t size, gfp_t flags)
|
|
{
|
|
struct kmem_cache *s;
|
|
void *ret;
|
|
|
|
if (unlikely(size > SLUB_MAX_SIZE))
|
|
return kmalloc_large(size, flags);
|
|
|
|
s = get_slab(size, flags);
|
|
|
|
if (unlikely(ZERO_OR_NULL_PTR(s)))
|
|
return s;
|
|
|
|
ret = slab_alloc(s, flags, NUMA_NO_NODE, _RET_IP_);
|
|
|
|
trace_kmalloc(_RET_IP_, ret, size, s->size, flags);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(__kmalloc);
|
|
|
|
#ifdef CONFIG_NUMA
|
|
static void *kmalloc_large_node(size_t size, gfp_t flags, int node)
|
|
{
|
|
struct page *page;
|
|
void *ptr = NULL;
|
|
|
|
flags |= __GFP_COMP | __GFP_NOTRACK;
|
|
page = alloc_pages_node(node, flags, get_order(size));
|
|
if (page)
|
|
ptr = page_address(page);
|
|
|
|
kmemleak_alloc(ptr, size, 1, flags);
|
|
return ptr;
|
|
}
|
|
|
|
void *__kmalloc_node(size_t size, gfp_t flags, int node)
|
|
{
|
|
struct kmem_cache *s;
|
|
void *ret;
|
|
|
|
if (unlikely(size > SLUB_MAX_SIZE)) {
|
|
ret = kmalloc_large_node(size, flags, node);
|
|
|
|
trace_kmalloc_node(_RET_IP_, ret,
|
|
size, PAGE_SIZE << get_order(size),
|
|
flags, node);
|
|
|
|
return ret;
|
|
}
|
|
|
|
s = get_slab(size, flags);
|
|
|
|
if (unlikely(ZERO_OR_NULL_PTR(s)))
|
|
return s;
|
|
|
|
ret = slab_alloc(s, flags, node, _RET_IP_);
|
|
|
|
trace_kmalloc_node(_RET_IP_, ret, size, s->size, flags, node);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(__kmalloc_node);
|
|
#endif
|
|
|
|
size_t ksize(const void *object)
|
|
{
|
|
struct page *page;
|
|
|
|
if (unlikely(object == ZERO_SIZE_PTR))
|
|
return 0;
|
|
|
|
page = virt_to_head_page(object);
|
|
|
|
if (unlikely(!PageSlab(page))) {
|
|
WARN_ON(!PageCompound(page));
|
|
return PAGE_SIZE << compound_order(page);
|
|
}
|
|
|
|
return slab_ksize(page->slab);
|
|
}
|
|
EXPORT_SYMBOL(ksize);
|
|
|
|
#ifdef CONFIG_SLUB_DEBUG
|
|
bool verify_mem_not_deleted(const void *x)
|
|
{
|
|
struct page *page;
|
|
void *object = (void *)x;
|
|
unsigned long flags;
|
|
bool rv;
|
|
|
|
if (unlikely(ZERO_OR_NULL_PTR(x)))
|
|
return false;
|
|
|
|
local_irq_save(flags);
|
|
|
|
page = virt_to_head_page(x);
|
|
if (unlikely(!PageSlab(page))) {
|
|
/* maybe it was from stack? */
|
|
rv = true;
|
|
goto out_unlock;
|
|
}
|
|
|
|
slab_lock(page);
|
|
if (on_freelist(page->slab, page, object)) {
|
|
object_err(page->slab, page, object, "Object is on free-list");
|
|
rv = false;
|
|
} else {
|
|
rv = true;
|
|
}
|
|
slab_unlock(page);
|
|
|
|
out_unlock:
|
|
local_irq_restore(flags);
|
|
return rv;
|
|
}
|
|
EXPORT_SYMBOL(verify_mem_not_deleted);
|
|
#endif
|
|
|
|
void kfree(const void *x)
|
|
{
|
|
struct page *page;
|
|
void *object = (void *)x;
|
|
|
|
trace_kfree(_RET_IP_, x);
|
|
|
|
if (unlikely(ZERO_OR_NULL_PTR(x)))
|
|
return;
|
|
|
|
page = virt_to_head_page(x);
|
|
if (unlikely(!PageSlab(page))) {
|
|
BUG_ON(!PageCompound(page));
|
|
kmemleak_free(x);
|
|
put_page(page);
|
|
return;
|
|
}
|
|
slab_free(page->slab, page, object, _RET_IP_);
|
|
}
|
|
EXPORT_SYMBOL(kfree);
|
|
|
|
/*
|
|
* kmem_cache_shrink removes empty slabs from the partial lists and sorts
|
|
* the remaining slabs by the number of items in use. The slabs with the
|
|
* most items in use come first. New allocations will then fill those up
|
|
* and thus they can be removed from the partial lists.
|
|
*
|
|
* The slabs with the least items are placed last. This results in them
|
|
* being allocated from last increasing the chance that the last objects
|
|
* are freed in them.
|
|
*/
|
|
int kmem_cache_shrink(struct kmem_cache *s)
|
|
{
|
|
int node;
|
|
int i;
|
|
struct kmem_cache_node *n;
|
|
struct page *page;
|
|
struct page *t;
|
|
int objects = oo_objects(s->max);
|
|
struct list_head *slabs_by_inuse =
|
|
kmalloc(sizeof(struct list_head) * objects, GFP_KERNEL);
|
|
unsigned long flags;
|
|
|
|
if (!slabs_by_inuse)
|
|
return -ENOMEM;
|
|
|
|
flush_all(s);
|
|
for_each_node_state(node, N_NORMAL_MEMORY) {
|
|
n = get_node(s, node);
|
|
|
|
if (!n->nr_partial)
|
|
continue;
|
|
|
|
for (i = 0; i < objects; i++)
|
|
INIT_LIST_HEAD(slabs_by_inuse + i);
|
|
|
|
spin_lock_irqsave(&n->list_lock, flags);
|
|
|
|
/*
|
|
* Build lists indexed by the items in use in each slab.
|
|
*
|
|
* Note that concurrent frees may occur while we hold the
|
|
* list_lock. page->inuse here is the upper limit.
|
|
*/
|
|
list_for_each_entry_safe(page, t, &n->partial, lru) {
|
|
list_move(&page->lru, slabs_by_inuse + page->inuse);
|
|
if (!page->inuse)
|
|
n->nr_partial--;
|
|
}
|
|
|
|
/*
|
|
* Rebuild the partial list with the slabs filled up most
|
|
* first and the least used slabs at the end.
|
|
*/
|
|
for (i = objects - 1; i > 0; i--)
|
|
list_splice(slabs_by_inuse + i, n->partial.prev);
|
|
|
|
spin_unlock_irqrestore(&n->list_lock, flags);
|
|
|
|
/* Release empty slabs */
|
|
list_for_each_entry_safe(page, t, slabs_by_inuse, lru)
|
|
discard_slab(s, page);
|
|
}
|
|
|
|
kfree(slabs_by_inuse);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_shrink);
|
|
|
|
#if defined(CONFIG_MEMORY_HOTPLUG)
|
|
static int slab_mem_going_offline_callback(void *arg)
|
|
{
|
|
struct kmem_cache *s;
|
|
|
|
down_read(&slub_lock);
|
|
list_for_each_entry(s, &slab_caches, list)
|
|
kmem_cache_shrink(s);
|
|
up_read(&slub_lock);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void slab_mem_offline_callback(void *arg)
|
|
{
|
|
struct kmem_cache_node *n;
|
|
struct kmem_cache *s;
|
|
struct memory_notify *marg = arg;
|
|
int offline_node;
|
|
|
|
offline_node = marg->status_change_nid;
|
|
|
|
/*
|
|
* If the node still has available memory. we need kmem_cache_node
|
|
* for it yet.
|
|
*/
|
|
if (offline_node < 0)
|
|
return;
|
|
|
|
down_read(&slub_lock);
|
|
list_for_each_entry(s, &slab_caches, list) {
|
|
n = get_node(s, offline_node);
|
|
if (n) {
|
|
/*
|
|
* if n->nr_slabs > 0, slabs still exist on the node
|
|
* that is going down. We were unable to free them,
|
|
* and offline_pages() function shouldn't call this
|
|
* callback. So, we must fail.
|
|
*/
|
|
BUG_ON(slabs_node(s, offline_node));
|
|
|
|
s->node[offline_node] = NULL;
|
|
kmem_cache_free(kmem_cache_node, n);
|
|
}
|
|
}
|
|
up_read(&slub_lock);
|
|
}
|
|
|
|
static int slab_mem_going_online_callback(void *arg)
|
|
{
|
|
struct kmem_cache_node *n;
|
|
struct kmem_cache *s;
|
|
struct memory_notify *marg = arg;
|
|
int nid = marg->status_change_nid;
|
|
int ret = 0;
|
|
|
|
/*
|
|
* If the node's memory is already available, then kmem_cache_node is
|
|
* already created. Nothing to do.
|
|
*/
|
|
if (nid < 0)
|
|
return 0;
|
|
|
|
/*
|
|
* We are bringing a node online. No memory is available yet. We must
|
|
* allocate a kmem_cache_node structure in order to bring the node
|
|
* online.
|
|
*/
|
|
down_read(&slub_lock);
|
|
list_for_each_entry(s, &slab_caches, list) {
|
|
/*
|
|
* XXX: kmem_cache_alloc_node will fallback to other nodes
|
|
* since memory is not yet available from the node that
|
|
* is brought up.
|
|
*/
|
|
n = kmem_cache_alloc(kmem_cache_node, GFP_KERNEL);
|
|
if (!n) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
init_kmem_cache_node(n, s);
|
|
s->node[nid] = n;
|
|
}
|
|
out:
|
|
up_read(&slub_lock);
|
|
return ret;
|
|
}
|
|
|
|
static int slab_memory_callback(struct notifier_block *self,
|
|
unsigned long action, void *arg)
|
|
{
|
|
int ret = 0;
|
|
|
|
switch (action) {
|
|
case MEM_GOING_ONLINE:
|
|
ret = slab_mem_going_online_callback(arg);
|
|
break;
|
|
case MEM_GOING_OFFLINE:
|
|
ret = slab_mem_going_offline_callback(arg);
|
|
break;
|
|
case MEM_OFFLINE:
|
|
case MEM_CANCEL_ONLINE:
|
|
slab_mem_offline_callback(arg);
|
|
break;
|
|
case MEM_ONLINE:
|
|
case MEM_CANCEL_OFFLINE:
|
|
break;
|
|
}
|
|
if (ret)
|
|
ret = notifier_from_errno(ret);
|
|
else
|
|
ret = NOTIFY_OK;
|
|
return ret;
|
|
}
|
|
|
|
#endif /* CONFIG_MEMORY_HOTPLUG */
|
|
|
|
/********************************************************************
|
|
* Basic setup of slabs
|
|
*******************************************************************/
|
|
|
|
/*
|
|
* Used for early kmem_cache structures that were allocated using
|
|
* the page allocator
|
|
*/
|
|
|
|
static void __init kmem_cache_bootstrap_fixup(struct kmem_cache *s)
|
|
{
|
|
int node;
|
|
|
|
list_add(&s->list, &slab_caches);
|
|
s->refcount = -1;
|
|
|
|
for_each_node_state(node, N_NORMAL_MEMORY) {
|
|
struct kmem_cache_node *n = get_node(s, node);
|
|
struct page *p;
|
|
|
|
if (n) {
|
|
list_for_each_entry(p, &n->partial, lru)
|
|
p->slab = s;
|
|
|
|
#ifdef CONFIG_SLUB_DEBUG
|
|
list_for_each_entry(p, &n->full, lru)
|
|
p->slab = s;
|
|
#endif
|
|
}
|
|
}
|
|
}
|
|
|
|
void __init kmem_cache_init(void)
|
|
{
|
|
int i;
|
|
int caches = 0;
|
|
struct kmem_cache *temp_kmem_cache;
|
|
int order;
|
|
struct kmem_cache *temp_kmem_cache_node;
|
|
unsigned long kmalloc_size;
|
|
|
|
if (debug_guardpage_minorder())
|
|
slub_max_order = 0;
|
|
|
|
kmem_size = offsetof(struct kmem_cache, node) +
|
|
nr_node_ids * sizeof(struct kmem_cache_node *);
|
|
|
|
/* Allocate two kmem_caches from the page allocator */
|
|
kmalloc_size = ALIGN(kmem_size, cache_line_size());
|
|
order = get_order(2 * kmalloc_size);
|
|
kmem_cache = (void *)__get_free_pages(GFP_NOWAIT, order);
|
|
|
|
/*
|
|
* Must first have the slab cache available for the allocations of the
|
|
* struct kmem_cache_node's. There is special bootstrap code in
|
|
* kmem_cache_open for slab_state == DOWN.
|
|
*/
|
|
kmem_cache_node = (void *)kmem_cache + kmalloc_size;
|
|
|
|
kmem_cache_open(kmem_cache_node, "kmem_cache_node",
|
|
sizeof(struct kmem_cache_node),
|
|
0, SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL);
|
|
|
|
hotplug_memory_notifier(slab_memory_callback, SLAB_CALLBACK_PRI);
|
|
|
|
/* Able to allocate the per node structures */
|
|
slab_state = PARTIAL;
|
|
|
|
temp_kmem_cache = kmem_cache;
|
|
kmem_cache_open(kmem_cache, "kmem_cache", kmem_size,
|
|
0, SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL);
|
|
kmem_cache = kmem_cache_alloc(kmem_cache, GFP_NOWAIT);
|
|
memcpy(kmem_cache, temp_kmem_cache, kmem_size);
|
|
|
|
/*
|
|
* Allocate kmem_cache_node properly from the kmem_cache slab.
|
|
* kmem_cache_node is separately allocated so no need to
|
|
* update any list pointers.
|
|
*/
|
|
temp_kmem_cache_node = kmem_cache_node;
|
|
|
|
kmem_cache_node = kmem_cache_alloc(kmem_cache, GFP_NOWAIT);
|
|
memcpy(kmem_cache_node, temp_kmem_cache_node, kmem_size);
|
|
|
|
kmem_cache_bootstrap_fixup(kmem_cache_node);
|
|
|
|
caches++;
|
|
kmem_cache_bootstrap_fixup(kmem_cache);
|
|
caches++;
|
|
/* Free temporary boot structure */
|
|
free_pages((unsigned long)temp_kmem_cache, order);
|
|
|
|
/* Now we can use the kmem_cache to allocate kmalloc slabs */
|
|
|
|
/*
|
|
* Patch up the size_index table if we have strange large alignment
|
|
* requirements for the kmalloc array. This is only the case for
|
|
* MIPS it seems. The standard arches will not generate any code here.
|
|
*
|
|
* Largest permitted alignment is 256 bytes due to the way we
|
|
* handle the index determination for the smaller caches.
|
|
*
|
|
* Make sure that nothing crazy happens if someone starts tinkering
|
|
* around with ARCH_KMALLOC_MINALIGN
|
|
*/
|
|
BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 ||
|
|
(KMALLOC_MIN_SIZE & (KMALLOC_MIN_SIZE - 1)));
|
|
|
|
for (i = 8; i < KMALLOC_MIN_SIZE; i += 8) {
|
|
int elem = size_index_elem(i);
|
|
if (elem >= ARRAY_SIZE(size_index))
|
|
break;
|
|
size_index[elem] = KMALLOC_SHIFT_LOW;
|
|
}
|
|
|
|
if (KMALLOC_MIN_SIZE == 64) {
|
|
/*
|
|
* The 96 byte size cache is not used if the alignment
|
|
* is 64 byte.
|
|
*/
|
|
for (i = 64 + 8; i <= 96; i += 8)
|
|
size_index[size_index_elem(i)] = 7;
|
|
} else if (KMALLOC_MIN_SIZE == 128) {
|
|
/*
|
|
* The 192 byte sized cache is not used if the alignment
|
|
* is 128 byte. Redirect kmalloc to use the 256 byte cache
|
|
* instead.
|
|
*/
|
|
for (i = 128 + 8; i <= 192; i += 8)
|
|
size_index[size_index_elem(i)] = 8;
|
|
}
|
|
|
|
/* Caches that are not of the two-to-the-power-of size */
|
|
if (KMALLOC_MIN_SIZE <= 32) {
|
|
kmalloc_caches[1] = create_kmalloc_cache("kmalloc-96", 96, 0);
|
|
caches++;
|
|
}
|
|
|
|
if (KMALLOC_MIN_SIZE <= 64) {
|
|
kmalloc_caches[2] = create_kmalloc_cache("kmalloc-192", 192, 0);
|
|
caches++;
|
|
}
|
|
|
|
for (i = KMALLOC_SHIFT_LOW; i < SLUB_PAGE_SHIFT; i++) {
|
|
kmalloc_caches[i] = create_kmalloc_cache("kmalloc", 1 << i, 0);
|
|
caches++;
|
|
}
|
|
|
|
slab_state = UP;
|
|
|
|
/* Provide the correct kmalloc names now that the caches are up */
|
|
if (KMALLOC_MIN_SIZE <= 32) {
|
|
kmalloc_caches[1]->name = kstrdup(kmalloc_caches[1]->name, GFP_NOWAIT);
|
|
BUG_ON(!kmalloc_caches[1]->name);
|
|
}
|
|
|
|
if (KMALLOC_MIN_SIZE <= 64) {
|
|
kmalloc_caches[2]->name = kstrdup(kmalloc_caches[2]->name, GFP_NOWAIT);
|
|
BUG_ON(!kmalloc_caches[2]->name);
|
|
}
|
|
|
|
for (i = KMALLOC_SHIFT_LOW; i < SLUB_PAGE_SHIFT; i++) {
|
|
char *s = kasprintf(GFP_NOWAIT, "kmalloc-%d", 1 << i);
|
|
|
|
BUG_ON(!s);
|
|
kmalloc_caches[i]->name = s;
|
|
}
|
|
|
|
#ifdef CONFIG_SMP
|
|
register_cpu_notifier(&slab_notifier);
|
|
#endif
|
|
|
|
#ifdef CONFIG_ZONE_DMA
|
|
for (i = 0; i < SLUB_PAGE_SHIFT; i++) {
|
|
struct kmem_cache *s = kmalloc_caches[i];
|
|
|
|
if (s && s->size) {
|
|
char *name = kasprintf(GFP_NOWAIT,
|
|
"dma-kmalloc-%d", s->objsize);
|
|
|
|
BUG_ON(!name);
|
|
kmalloc_dma_caches[i] = create_kmalloc_cache(name,
|
|
s->objsize, SLAB_CACHE_DMA);
|
|
}
|
|
}
|
|
#endif
|
|
printk(KERN_INFO
|
|
"SLUB: Genslabs=%d, HWalign=%d, Order=%d-%d, MinObjects=%d,"
|
|
" CPUs=%d, Nodes=%d\n",
|
|
caches, cache_line_size(),
|
|
slub_min_order, slub_max_order, slub_min_objects,
|
|
nr_cpu_ids, nr_node_ids);
|
|
}
|
|
|
|
void __init kmem_cache_init_late(void)
|
|
{
|
|
}
|
|
|
|
/*
|
|
* Find a mergeable slab cache
|
|
*/
|
|
static int slab_unmergeable(struct kmem_cache *s)
|
|
{
|
|
if (slub_nomerge || (s->flags & SLUB_NEVER_MERGE))
|
|
return 1;
|
|
|
|
if (s->ctor)
|
|
return 1;
|
|
|
|
/*
|
|
* We may have set a slab to be unmergeable during bootstrap.
|
|
*/
|
|
if (s->refcount < 0)
|
|
return 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct kmem_cache *find_mergeable(size_t size,
|
|
size_t align, unsigned long flags, const char *name,
|
|
void (*ctor)(void *))
|
|
{
|
|
struct kmem_cache *s;
|
|
|
|
if (slub_nomerge || (flags & SLUB_NEVER_MERGE))
|
|
return NULL;
|
|
|
|
if (ctor)
|
|
return NULL;
|
|
|
|
size = ALIGN(size, sizeof(void *));
|
|
align = calculate_alignment(flags, align, size);
|
|
size = ALIGN(size, align);
|
|
flags = kmem_cache_flags(size, flags, name, NULL);
|
|
|
|
list_for_each_entry(s, &slab_caches, list) {
|
|
if (slab_unmergeable(s))
|
|
continue;
|
|
|
|
if (size > s->size)
|
|
continue;
|
|
|
|
if ((flags & SLUB_MERGE_SAME) != (s->flags & SLUB_MERGE_SAME))
|
|
continue;
|
|
/*
|
|
* Check if alignment is compatible.
|
|
* Courtesy of Adrian Drzewiecki
|
|
*/
|
|
if ((s->size & ~(align - 1)) != s->size)
|
|
continue;
|
|
|
|
if (s->size - size >= sizeof(void *))
|
|
continue;
|
|
|
|
return s;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
struct kmem_cache *kmem_cache_create(const char *name, size_t size,
|
|
size_t align, unsigned long flags, void (*ctor)(void *))
|
|
{
|
|
struct kmem_cache *s;
|
|
char *n;
|
|
|
|
if (WARN_ON(!name))
|
|
return NULL;
|
|
|
|
down_write(&slub_lock);
|
|
s = find_mergeable(size, align, flags, name, ctor);
|
|
if (s) {
|
|
s->refcount++;
|
|
/*
|
|
* Adjust the object sizes so that we clear
|
|
* the complete object on kzalloc.
|
|
*/
|
|
s->objsize = max(s->objsize, (int)size);
|
|
s->inuse = max_t(int, s->inuse, ALIGN(size, sizeof(void *)));
|
|
|
|
if (sysfs_slab_alias(s, name)) {
|
|
s->refcount--;
|
|
goto err;
|
|
}
|
|
up_write(&slub_lock);
|
|
return s;
|
|
}
|
|
|
|
n = kstrdup(name, GFP_KERNEL);
|
|
if (!n)
|
|
goto err;
|
|
|
|
s = kmalloc(kmem_size, GFP_KERNEL);
|
|
if (s) {
|
|
if (kmem_cache_open(s, n,
|
|
size, align, flags, ctor)) {
|
|
list_add(&s->list, &slab_caches);
|
|
if (sysfs_slab_add(s)) {
|
|
list_del(&s->list);
|
|
kfree(n);
|
|
kfree(s);
|
|
goto err;
|
|
}
|
|
up_write(&slub_lock);
|
|
return s;
|
|
}
|
|
kfree(n);
|
|
kfree(s);
|
|
}
|
|
err:
|
|
up_write(&slub_lock);
|
|
|
|
if (flags & SLAB_PANIC)
|
|
panic("Cannot create slabcache %s\n", name);
|
|
else
|
|
s = NULL;
|
|
return s;
|
|
}
|
|
EXPORT_SYMBOL(kmem_cache_create);
|
|
|
|
#ifdef CONFIG_SMP
|
|
/*
|
|
* Use the cpu notifier to insure that the cpu slabs are flushed when
|
|
* necessary.
|
|
*/
|
|
static int __cpuinit slab_cpuup_callback(struct notifier_block *nfb,
|
|
unsigned long action, void *hcpu)
|
|
{
|
|
long cpu = (long)hcpu;
|
|
struct kmem_cache *s;
|
|
unsigned long flags;
|
|
|
|
switch (action) {
|
|
case CPU_UP_CANCELED:
|
|
case CPU_UP_CANCELED_FROZEN:
|
|
case CPU_DEAD:
|
|
case CPU_DEAD_FROZEN:
|
|
down_read(&slub_lock);
|
|
list_for_each_entry(s, &slab_caches, list) {
|
|
local_irq_save(flags);
|
|
__flush_cpu_slab(s, cpu);
|
|
local_irq_restore(flags);
|
|
}
|
|
up_read(&slub_lock);
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
return NOTIFY_OK;
|
|
}
|
|
|
|
static struct notifier_block __cpuinitdata slab_notifier = {
|
|
.notifier_call = slab_cpuup_callback
|
|
};
|
|
|
|
#endif
|
|
|
|
void *__kmalloc_track_caller(size_t size, gfp_t gfpflags, unsigned long caller)
|
|
{
|
|
struct kmem_cache *s;
|
|
void *ret;
|
|
|
|
if (unlikely(size > SLUB_MAX_SIZE))
|
|
return kmalloc_large(size, gfpflags);
|
|
|
|
s = get_slab(size, gfpflags);
|
|
|
|
if (unlikely(ZERO_OR_NULL_PTR(s)))
|
|
return s;
|
|
|
|
ret = slab_alloc(s, gfpflags, NUMA_NO_NODE, caller);
|
|
|
|
/* Honor the call site pointer we received. */
|
|
trace_kmalloc(caller, ret, size, s->size, gfpflags);
|
|
|
|
return ret;
|
|
}
|
|
|
|
#ifdef CONFIG_NUMA
|
|
void *__kmalloc_node_track_caller(size_t size, gfp_t gfpflags,
|
|
int node, unsigned long caller)
|
|
{
|
|
struct kmem_cache *s;
|
|
void *ret;
|
|
|
|
if (unlikely(size > SLUB_MAX_SIZE)) {
|
|
ret = kmalloc_large_node(size, gfpflags, node);
|
|
|
|
trace_kmalloc_node(caller, ret,
|
|
size, PAGE_SIZE << get_order(size),
|
|
gfpflags, node);
|
|
|
|
return ret;
|
|
}
|
|
|
|
s = get_slab(size, gfpflags);
|
|
|
|
if (unlikely(ZERO_OR_NULL_PTR(s)))
|
|
return s;
|
|
|
|
ret = slab_alloc(s, gfpflags, node, caller);
|
|
|
|
/* Honor the call site pointer we received. */
|
|
trace_kmalloc_node(caller, ret, size, s->size, gfpflags, node);
|
|
|
|
return ret;
|
|
}
|
|
#endif
|
|
|
|
#ifdef CONFIG_SYSFS
|
|
static int count_inuse(struct page *page)
|
|
{
|
|
return page->inuse;
|
|
}
|
|
|
|
static int count_total(struct page *page)
|
|
{
|
|
return page->objects;
|
|
}
|
|
#endif
|
|
|
|
#ifdef CONFIG_SLUB_DEBUG
|
|
static int validate_slab(struct kmem_cache *s, struct page *page,
|
|
unsigned long *map)
|
|
{
|
|
void *p;
|
|
void *addr = page_address(page);
|
|
|
|
if (!check_slab(s, page) ||
|
|
!on_freelist(s, page, NULL))
|
|
return 0;
|
|
|
|
/* Now we know that a valid freelist exists */
|
|
bitmap_zero(map, page->objects);
|
|
|
|
get_map(s, page, map);
|
|
for_each_object(p, s, addr, page->objects) {
|
|
if (test_bit(slab_index(p, s, addr), map))
|
|
if (!check_object(s, page, p, SLUB_RED_INACTIVE))
|
|
return 0;
|
|
}
|
|
|
|
for_each_object(p, s, addr, page->objects)
|
|
if (!test_bit(slab_index(p, s, addr), map))
|
|
if (!check_object(s, page, p, SLUB_RED_ACTIVE))
|
|
return 0;
|
|
return 1;
|
|
}
|
|
|
|
static void validate_slab_slab(struct kmem_cache *s, struct page *page,
|
|
unsigned long *map)
|
|
{
|
|
slab_lock(page);
|
|
validate_slab(s, page, map);
|
|
slab_unlock(page);
|
|
}
|
|
|
|
static int validate_slab_node(struct kmem_cache *s,
|
|
struct kmem_cache_node *n, unsigned long *map)
|
|
{
|
|
unsigned long count = 0;
|
|
struct page *page;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&n->list_lock, flags);
|
|
|
|
list_for_each_entry(page, &n->partial, lru) {
|
|
validate_slab_slab(s, page, map);
|
|
count++;
|
|
}
|
|
if (count != n->nr_partial)
|
|
printk(KERN_ERR "SLUB %s: %ld partial slabs counted but "
|
|
"counter=%ld\n", s->name, count, n->nr_partial);
|
|
|
|
if (!(s->flags & SLAB_STORE_USER))
|
|
goto out;
|
|
|
|
list_for_each_entry(page, &n->full, lru) {
|
|
validate_slab_slab(s, page, map);
|
|
count++;
|
|
}
|
|
if (count != atomic_long_read(&n->nr_slabs))
|
|
printk(KERN_ERR "SLUB: %s %ld slabs counted but "
|
|
"counter=%ld\n", s->name, count,
|
|
atomic_long_read(&n->nr_slabs));
|
|
|
|
out:
|
|
spin_unlock_irqrestore(&n->list_lock, flags);
|
|
return count;
|
|
}
|
|
|
|
static long validate_slab_cache(struct kmem_cache *s)
|
|
{
|
|
int node;
|
|
unsigned long count = 0;
|
|
unsigned long *map = kmalloc(BITS_TO_LONGS(oo_objects(s->max)) *
|
|
sizeof(unsigned long), GFP_KERNEL);
|
|
|
|
if (!map)
|
|
return -ENOMEM;
|
|
|
|
flush_all(s);
|
|
for_each_node_state(node, N_NORMAL_MEMORY) {
|
|
struct kmem_cache_node *n = get_node(s, node);
|
|
|
|
count += validate_slab_node(s, n, map);
|
|
}
|
|
kfree(map);
|
|
return count;
|
|
}
|
|
/*
|
|
* Generate lists of code addresses where slabcache objects are allocated
|
|
* and freed.
|
|
*/
|
|
|
|
struct location {
|
|
unsigned long count;
|
|
unsigned long addr;
|
|
long long sum_time;
|
|
long min_time;
|
|
long max_time;
|
|
long min_pid;
|
|
long max_pid;
|
|
DECLARE_BITMAP(cpus, NR_CPUS);
|
|
nodemask_t nodes;
|
|
};
|
|
|
|
struct loc_track {
|
|
unsigned long max;
|
|
unsigned long count;
|
|
struct location *loc;
|
|
};
|
|
|
|
static void free_loc_track(struct loc_track *t)
|
|
{
|
|
if (t->max)
|
|
free_pages((unsigned long)t->loc,
|
|
get_order(sizeof(struct location) * t->max));
|
|
}
|
|
|
|
static int alloc_loc_track(struct loc_track *t, unsigned long max, gfp_t flags)
|
|
{
|
|
struct location *l;
|
|
int order;
|
|
|
|
order = get_order(sizeof(struct location) * max);
|
|
|
|
l = (void *)__get_free_pages(flags, order);
|
|
if (!l)
|
|
return 0;
|
|
|
|
if (t->count) {
|
|
memcpy(l, t->loc, sizeof(struct location) * t->count);
|
|
free_loc_track(t);
|
|
}
|
|
t->max = max;
|
|
t->loc = l;
|
|
return 1;
|
|
}
|
|
|
|
static int add_location(struct loc_track *t, struct kmem_cache *s,
|
|
const struct track *track)
|
|
{
|
|
long start, end, pos;
|
|
struct location *l;
|
|
unsigned long caddr;
|
|
unsigned long age = jiffies - track->when;
|
|
|
|
start = -1;
|
|
end = t->count;
|
|
|
|
for ( ; ; ) {
|
|
pos = start + (end - start + 1) / 2;
|
|
|
|
/*
|
|
* There is nothing at "end". If we end up there
|
|
* we need to add something to before end.
|
|
*/
|
|
if (pos == end)
|
|
break;
|
|
|
|
caddr = t->loc[pos].addr;
|
|
if (track->addr == caddr) {
|
|
|
|
l = &t->loc[pos];
|
|
l->count++;
|
|
if (track->when) {
|
|
l->sum_time += age;
|
|
if (age < l->min_time)
|
|
l->min_time = age;
|
|
if (age > l->max_time)
|
|
l->max_time = age;
|
|
|
|
if (track->pid < l->min_pid)
|
|
l->min_pid = track->pid;
|
|
if (track->pid > l->max_pid)
|
|
l->max_pid = track->pid;
|
|
|
|
cpumask_set_cpu(track->cpu,
|
|
to_cpumask(l->cpus));
|
|
}
|
|
node_set(page_to_nid(virt_to_page(track)), l->nodes);
|
|
return 1;
|
|
}
|
|
|
|
if (track->addr < caddr)
|
|
end = pos;
|
|
else
|
|
start = pos;
|
|
}
|
|
|
|
/*
|
|
* Not found. Insert new tracking element.
|
|
*/
|
|
if (t->count >= t->max && !alloc_loc_track(t, 2 * t->max, GFP_ATOMIC))
|
|
return 0;
|
|
|
|
l = t->loc + pos;
|
|
if (pos < t->count)
|
|
memmove(l + 1, l,
|
|
(t->count - pos) * sizeof(struct location));
|
|
t->count++;
|
|
l->count = 1;
|
|
l->addr = track->addr;
|
|
l->sum_time = age;
|
|
l->min_time = age;
|
|
l->max_time = age;
|
|
l->min_pid = track->pid;
|
|
l->max_pid = track->pid;
|
|
cpumask_clear(to_cpumask(l->cpus));
|
|
cpumask_set_cpu(track->cpu, to_cpumask(l->cpus));
|
|
nodes_clear(l->nodes);
|
|
node_set(page_to_nid(virt_to_page(track)), l->nodes);
|
|
return 1;
|
|
}
|
|
|
|
static void process_slab(struct loc_track *t, struct kmem_cache *s,
|
|
struct page *page, enum track_item alloc,
|
|
unsigned long *map)
|
|
{
|
|
void *addr = page_address(page);
|
|
void *p;
|
|
|
|
bitmap_zero(map, page->objects);
|
|
get_map(s, page, map);
|
|
|
|
for_each_object(p, s, addr, page->objects)
|
|
if (!test_bit(slab_index(p, s, addr), map))
|
|
add_location(t, s, get_track(s, p, alloc));
|
|
}
|
|
|
|
static int list_locations(struct kmem_cache *s, char *buf,
|
|
enum track_item alloc)
|
|
{
|
|
int len = 0;
|
|
unsigned long i;
|
|
struct loc_track t = { 0, 0, NULL };
|
|
int node;
|
|
unsigned long *map = kmalloc(BITS_TO_LONGS(oo_objects(s->max)) *
|
|
sizeof(unsigned long), GFP_KERNEL);
|
|
|
|
if (!map || !alloc_loc_track(&t, PAGE_SIZE / sizeof(struct location),
|
|
GFP_TEMPORARY)) {
|
|
kfree(map);
|
|
return sprintf(buf, "Out of memory\n");
|
|
}
|
|
/* Push back cpu slabs */
|
|
flush_all(s);
|
|
|
|
for_each_node_state(node, N_NORMAL_MEMORY) {
|
|
struct kmem_cache_node *n = get_node(s, node);
|
|
unsigned long flags;
|
|
struct page *page;
|
|
|
|
if (!atomic_long_read(&n->nr_slabs))
|
|
continue;
|
|
|
|
spin_lock_irqsave(&n->list_lock, flags);
|
|
list_for_each_entry(page, &n->partial, lru)
|
|
process_slab(&t, s, page, alloc, map);
|
|
list_for_each_entry(page, &n->full, lru)
|
|
process_slab(&t, s, page, alloc, map);
|
|
spin_unlock_irqrestore(&n->list_lock, flags);
|
|
}
|
|
|
|
for (i = 0; i < t.count; i++) {
|
|
struct location *l = &t.loc[i];
|
|
|
|
if (len > PAGE_SIZE - KSYM_SYMBOL_LEN - 100)
|
|
break;
|
|
len += sprintf(buf + len, "%7ld ", l->count);
|
|
|
|
if (l->addr)
|
|
len += sprintf(buf + len, "%pS", (void *)l->addr);
|
|
else
|
|
len += sprintf(buf + len, "<not-available>");
|
|
|
|
if (l->sum_time != l->min_time) {
|
|
len += sprintf(buf + len, " age=%ld/%ld/%ld",
|
|
l->min_time,
|
|
(long)div_u64(l->sum_time, l->count),
|
|
l->max_time);
|
|
} else
|
|
len += sprintf(buf + len, " age=%ld",
|
|
l->min_time);
|
|
|
|
if (l->min_pid != l->max_pid)
|
|
len += sprintf(buf + len, " pid=%ld-%ld",
|
|
l->min_pid, l->max_pid);
|
|
else
|
|
len += sprintf(buf + len, " pid=%ld",
|
|
l->min_pid);
|
|
|
|
if (num_online_cpus() > 1 &&
|
|
!cpumask_empty(to_cpumask(l->cpus)) &&
|
|
len < PAGE_SIZE - 60) {
|
|
len += sprintf(buf + len, " cpus=");
|
|
len += cpulist_scnprintf(buf + len, PAGE_SIZE - len - 50,
|
|
to_cpumask(l->cpus));
|
|
}
|
|
|
|
if (nr_online_nodes > 1 && !nodes_empty(l->nodes) &&
|
|
len < PAGE_SIZE - 60) {
|
|
len += sprintf(buf + len, " nodes=");
|
|
len += nodelist_scnprintf(buf + len, PAGE_SIZE - len - 50,
|
|
l->nodes);
|
|
}
|
|
|
|
len += sprintf(buf + len, "\n");
|
|
}
|
|
|
|
free_loc_track(&t);
|
|
kfree(map);
|
|
if (!t.count)
|
|
len += sprintf(buf, "No data\n");
|
|
return len;
|
|
}
|
|
#endif
|
|
|
|
#ifdef SLUB_RESILIENCY_TEST
|
|
static void resiliency_test(void)
|
|
{
|
|
u8 *p;
|
|
|
|
BUILD_BUG_ON(KMALLOC_MIN_SIZE > 16 || SLUB_PAGE_SHIFT < 10);
|
|
|
|
printk(KERN_ERR "SLUB resiliency testing\n");
|
|
printk(KERN_ERR "-----------------------\n");
|
|
printk(KERN_ERR "A. Corruption after allocation\n");
|
|
|
|
p = kzalloc(16, GFP_KERNEL);
|
|
p[16] = 0x12;
|
|
printk(KERN_ERR "\n1. kmalloc-16: Clobber Redzone/next pointer"
|
|
" 0x12->0x%p\n\n", p + 16);
|
|
|
|
validate_slab_cache(kmalloc_caches[4]);
|
|
|
|
/* Hmmm... The next two are dangerous */
|
|
p = kzalloc(32, GFP_KERNEL);
|
|
p[32 + sizeof(void *)] = 0x34;
|
|
printk(KERN_ERR "\n2. kmalloc-32: Clobber next pointer/next slab"
|
|
" 0x34 -> -0x%p\n", p);
|
|
printk(KERN_ERR
|
|
"If allocated object is overwritten then not detectable\n\n");
|
|
|
|
validate_slab_cache(kmalloc_caches[5]);
|
|
p = kzalloc(64, GFP_KERNEL);
|
|
p += 64 + (get_cycles() & 0xff) * sizeof(void *);
|
|
*p = 0x56;
|
|
printk(KERN_ERR "\n3. kmalloc-64: corrupting random byte 0x56->0x%p\n",
|
|
p);
|
|
printk(KERN_ERR
|
|
"If allocated object is overwritten then not detectable\n\n");
|
|
validate_slab_cache(kmalloc_caches[6]);
|
|
|
|
printk(KERN_ERR "\nB. Corruption after free\n");
|
|
p = kzalloc(128, GFP_KERNEL);
|
|
kfree(p);
|
|
*p = 0x78;
|
|
printk(KERN_ERR "1. kmalloc-128: Clobber first word 0x78->0x%p\n\n", p);
|
|
validate_slab_cache(kmalloc_caches[7]);
|
|
|
|
p = kzalloc(256, GFP_KERNEL);
|
|
kfree(p);
|
|
p[50] = 0x9a;
|
|
printk(KERN_ERR "\n2. kmalloc-256: Clobber 50th byte 0x9a->0x%p\n\n",
|
|
p);
|
|
validate_slab_cache(kmalloc_caches[8]);
|
|
|
|
p = kzalloc(512, GFP_KERNEL);
|
|
kfree(p);
|
|
p[512] = 0xab;
|
|
printk(KERN_ERR "\n3. kmalloc-512: Clobber redzone 0xab->0x%p\n\n", p);
|
|
validate_slab_cache(kmalloc_caches[9]);
|
|
}
|
|
#else
|
|
#ifdef CONFIG_SYSFS
|
|
static void resiliency_test(void) {};
|
|
#endif
|
|
#endif
|
|
|
|
#ifdef CONFIG_SYSFS
|
|
enum slab_stat_type {
|
|
SL_ALL, /* All slabs */
|
|
SL_PARTIAL, /* Only partially allocated slabs */
|
|
SL_CPU, /* Only slabs used for cpu caches */
|
|
SL_OBJECTS, /* Determine allocated objects not slabs */
|
|
SL_TOTAL /* Determine object capacity not slabs */
|
|
};
|
|
|
|
#define SO_ALL (1 << SL_ALL)
|
|
#define SO_PARTIAL (1 << SL_PARTIAL)
|
|
#define SO_CPU (1 << SL_CPU)
|
|
#define SO_OBJECTS (1 << SL_OBJECTS)
|
|
#define SO_TOTAL (1 << SL_TOTAL)
|
|
|
|
static ssize_t show_slab_objects(struct kmem_cache *s,
|
|
char *buf, unsigned long flags)
|
|
{
|
|
unsigned long total = 0;
|
|
int node;
|
|
int x;
|
|
unsigned long *nodes;
|
|
unsigned long *per_cpu;
|
|
|
|
nodes = kzalloc(2 * sizeof(unsigned long) * nr_node_ids, GFP_KERNEL);
|
|
if (!nodes)
|
|
return -ENOMEM;
|
|
per_cpu = nodes + nr_node_ids;
|
|
|
|
if (flags & SO_CPU) {
|
|
int cpu;
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
struct kmem_cache_cpu *c = per_cpu_ptr(s->cpu_slab, cpu);
|
|
int node = ACCESS_ONCE(c->node);
|
|
struct page *page;
|
|
|
|
if (node < 0)
|
|
continue;
|
|
page = ACCESS_ONCE(c->page);
|
|
if (page) {
|
|
if (flags & SO_TOTAL)
|
|
x = page->objects;
|
|
else if (flags & SO_OBJECTS)
|
|
x = page->inuse;
|
|
else
|
|
x = 1;
|
|
|
|
total += x;
|
|
nodes[node] += x;
|
|
}
|
|
page = c->partial;
|
|
|
|
if (page) {
|
|
x = page->pobjects;
|
|
total += x;
|
|
nodes[node] += x;
|
|
}
|
|
per_cpu[node]++;
|
|
}
|
|
}
|
|
|
|
lock_memory_hotplug();
|
|
#ifdef CONFIG_SLUB_DEBUG
|
|
if (flags & SO_ALL) {
|
|
for_each_node_state(node, N_NORMAL_MEMORY) {
|
|
struct kmem_cache_node *n = get_node(s, node);
|
|
|
|
if (flags & SO_TOTAL)
|
|
x = atomic_long_read(&n->total_objects);
|
|
else if (flags & SO_OBJECTS)
|
|
x = atomic_long_read(&n->total_objects) -
|
|
count_partial(n, count_free);
|
|
|
|
else
|
|
x = atomic_long_read(&n->nr_slabs);
|
|
total += x;
|
|
nodes[node] += x;
|
|
}
|
|
|
|
} else
|
|
#endif
|
|
if (flags & SO_PARTIAL) {
|
|
for_each_node_state(node, N_NORMAL_MEMORY) {
|
|
struct kmem_cache_node *n = get_node(s, node);
|
|
|
|
if (flags & SO_TOTAL)
|
|
x = count_partial(n, count_total);
|
|
else if (flags & SO_OBJECTS)
|
|
x = count_partial(n, count_inuse);
|
|
else
|
|
x = n->nr_partial;
|
|
total += x;
|
|
nodes[node] += x;
|
|
}
|
|
}
|
|
x = sprintf(buf, "%lu", total);
|
|
#ifdef CONFIG_NUMA
|
|
for_each_node_state(node, N_NORMAL_MEMORY)
|
|
if (nodes[node])
|
|
x += sprintf(buf + x, " N%d=%lu",
|
|
node, nodes[node]);
|
|
#endif
|
|
unlock_memory_hotplug();
|
|
kfree(nodes);
|
|
return x + sprintf(buf + x, "\n");
|
|
}
|
|
|
|
#ifdef CONFIG_SLUB_DEBUG
|
|
static int any_slab_objects(struct kmem_cache *s)
|
|
{
|
|
int node;
|
|
|
|
for_each_online_node(node) {
|
|
struct kmem_cache_node *n = get_node(s, node);
|
|
|
|
if (!n)
|
|
continue;
|
|
|
|
if (atomic_long_read(&n->total_objects))
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
#define to_slab_attr(n) container_of(n, struct slab_attribute, attr)
|
|
#define to_slab(n) container_of(n, struct kmem_cache, kobj)
|
|
|
|
struct slab_attribute {
|
|
struct attribute attr;
|
|
ssize_t (*show)(struct kmem_cache *s, char *buf);
|
|
ssize_t (*store)(struct kmem_cache *s, const char *x, size_t count);
|
|
};
|
|
|
|
#define SLAB_ATTR_RO(_name) \
|
|
static struct slab_attribute _name##_attr = \
|
|
__ATTR(_name, 0400, _name##_show, NULL)
|
|
|
|
#define SLAB_ATTR(_name) \
|
|
static struct slab_attribute _name##_attr = \
|
|
__ATTR(_name, 0600, _name##_show, _name##_store)
|
|
|
|
static ssize_t slab_size_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sprintf(buf, "%d\n", s->size);
|
|
}
|
|
SLAB_ATTR_RO(slab_size);
|
|
|
|
static ssize_t align_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sprintf(buf, "%d\n", s->align);
|
|
}
|
|
SLAB_ATTR_RO(align);
|
|
|
|
static ssize_t object_size_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sprintf(buf, "%d\n", s->objsize);
|
|
}
|
|
SLAB_ATTR_RO(object_size);
|
|
|
|
static ssize_t objs_per_slab_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sprintf(buf, "%d\n", oo_objects(s->oo));
|
|
}
|
|
SLAB_ATTR_RO(objs_per_slab);
|
|
|
|
static ssize_t order_store(struct kmem_cache *s,
|
|
const char *buf, size_t length)
|
|
{
|
|
unsigned long order;
|
|
int err;
|
|
|
|
err = strict_strtoul(buf, 10, &order);
|
|
if (err)
|
|
return err;
|
|
|
|
if (order > slub_max_order || order < slub_min_order)
|
|
return -EINVAL;
|
|
|
|
calculate_sizes(s, order);
|
|
return length;
|
|
}
|
|
|
|
static ssize_t order_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sprintf(buf, "%d\n", oo_order(s->oo));
|
|
}
|
|
SLAB_ATTR(order);
|
|
|
|
static ssize_t min_partial_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sprintf(buf, "%lu\n", s->min_partial);
|
|
}
|
|
|
|
static ssize_t min_partial_store(struct kmem_cache *s, const char *buf,
|
|
size_t length)
|
|
{
|
|
unsigned long min;
|
|
int err;
|
|
|
|
err = strict_strtoul(buf, 10, &min);
|
|
if (err)
|
|
return err;
|
|
|
|
set_min_partial(s, min);
|
|
return length;
|
|
}
|
|
SLAB_ATTR(min_partial);
|
|
|
|
static ssize_t cpu_partial_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sprintf(buf, "%u\n", s->cpu_partial);
|
|
}
|
|
|
|
static ssize_t cpu_partial_store(struct kmem_cache *s, const char *buf,
|
|
size_t length)
|
|
{
|
|
unsigned long objects;
|
|
int err;
|
|
|
|
err = strict_strtoul(buf, 10, &objects);
|
|
if (err)
|
|
return err;
|
|
if (objects && kmem_cache_debug(s))
|
|
return -EINVAL;
|
|
|
|
s->cpu_partial = objects;
|
|
flush_all(s);
|
|
return length;
|
|
}
|
|
SLAB_ATTR(cpu_partial);
|
|
|
|
static ssize_t ctor_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
if (!s->ctor)
|
|
return 0;
|
|
return sprintf(buf, "%pS\n", s->ctor);
|
|
}
|
|
SLAB_ATTR_RO(ctor);
|
|
|
|
static ssize_t aliases_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sprintf(buf, "%d\n", s->refcount - 1);
|
|
}
|
|
SLAB_ATTR_RO(aliases);
|
|
|
|
static ssize_t partial_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return show_slab_objects(s, buf, SO_PARTIAL);
|
|
}
|
|
SLAB_ATTR_RO(partial);
|
|
|
|
static ssize_t cpu_slabs_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return show_slab_objects(s, buf, SO_CPU);
|
|
}
|
|
SLAB_ATTR_RO(cpu_slabs);
|
|
|
|
static ssize_t objects_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return show_slab_objects(s, buf, SO_ALL|SO_OBJECTS);
|
|
}
|
|
SLAB_ATTR_RO(objects);
|
|
|
|
static ssize_t objects_partial_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return show_slab_objects(s, buf, SO_PARTIAL|SO_OBJECTS);
|
|
}
|
|
SLAB_ATTR_RO(objects_partial);
|
|
|
|
static ssize_t slabs_cpu_partial_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
int objects = 0;
|
|
int pages = 0;
|
|
int cpu;
|
|
int len;
|
|
|
|
for_each_online_cpu(cpu) {
|
|
struct page *page = per_cpu_ptr(s->cpu_slab, cpu)->partial;
|
|
|
|
if (page) {
|
|
pages += page->pages;
|
|
objects += page->pobjects;
|
|
}
|
|
}
|
|
|
|
len = sprintf(buf, "%d(%d)", objects, pages);
|
|
|
|
#ifdef CONFIG_SMP
|
|
for_each_online_cpu(cpu) {
|
|
struct page *page = per_cpu_ptr(s->cpu_slab, cpu) ->partial;
|
|
|
|
if (page && len < PAGE_SIZE - 20)
|
|
len += sprintf(buf + len, " C%d=%d(%d)", cpu,
|
|
page->pobjects, page->pages);
|
|
}
|
|
#endif
|
|
return len + sprintf(buf + len, "\n");
|
|
}
|
|
SLAB_ATTR_RO(slabs_cpu_partial);
|
|
|
|
static ssize_t reclaim_account_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sprintf(buf, "%d\n", !!(s->flags & SLAB_RECLAIM_ACCOUNT));
|
|
}
|
|
|
|
static ssize_t reclaim_account_store(struct kmem_cache *s,
|
|
const char *buf, size_t length)
|
|
{
|
|
s->flags &= ~SLAB_RECLAIM_ACCOUNT;
|
|
if (buf[0] == '1')
|
|
s->flags |= SLAB_RECLAIM_ACCOUNT;
|
|
return length;
|
|
}
|
|
SLAB_ATTR(reclaim_account);
|
|
|
|
static ssize_t hwcache_align_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sprintf(buf, "%d\n", !!(s->flags & SLAB_HWCACHE_ALIGN));
|
|
}
|
|
SLAB_ATTR_RO(hwcache_align);
|
|
|
|
#ifdef CONFIG_ZONE_DMA
|
|
static ssize_t cache_dma_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sprintf(buf, "%d\n", !!(s->flags & SLAB_CACHE_DMA));
|
|
}
|
|
SLAB_ATTR_RO(cache_dma);
|
|
#endif
|
|
|
|
static ssize_t destroy_by_rcu_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sprintf(buf, "%d\n", !!(s->flags & SLAB_DESTROY_BY_RCU));
|
|
}
|
|
SLAB_ATTR_RO(destroy_by_rcu);
|
|
|
|
static ssize_t reserved_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sprintf(buf, "%d\n", s->reserved);
|
|
}
|
|
SLAB_ATTR_RO(reserved);
|
|
|
|
#ifdef CONFIG_SLUB_DEBUG
|
|
static ssize_t slabs_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return show_slab_objects(s, buf, SO_ALL);
|
|
}
|
|
SLAB_ATTR_RO(slabs);
|
|
|
|
static ssize_t total_objects_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return show_slab_objects(s, buf, SO_ALL|SO_TOTAL);
|
|
}
|
|
SLAB_ATTR_RO(total_objects);
|
|
|
|
static ssize_t sanity_checks_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sprintf(buf, "%d\n", !!(s->flags & SLAB_DEBUG_FREE));
|
|
}
|
|
|
|
static ssize_t sanity_checks_store(struct kmem_cache *s,
|
|
const char *buf, size_t length)
|
|
{
|
|
s->flags &= ~SLAB_DEBUG_FREE;
|
|
if (buf[0] == '1') {
|
|
s->flags &= ~__CMPXCHG_DOUBLE;
|
|
s->flags |= SLAB_DEBUG_FREE;
|
|
}
|
|
return length;
|
|
}
|
|
SLAB_ATTR(sanity_checks);
|
|
|
|
static ssize_t trace_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sprintf(buf, "%d\n", !!(s->flags & SLAB_TRACE));
|
|
}
|
|
|
|
static ssize_t trace_store(struct kmem_cache *s, const char *buf,
|
|
size_t length)
|
|
{
|
|
s->flags &= ~SLAB_TRACE;
|
|
if (buf[0] == '1') {
|
|
s->flags &= ~__CMPXCHG_DOUBLE;
|
|
s->flags |= SLAB_TRACE;
|
|
}
|
|
return length;
|
|
}
|
|
SLAB_ATTR(trace);
|
|
|
|
static ssize_t red_zone_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sprintf(buf, "%d\n", !!(s->flags & SLAB_RED_ZONE));
|
|
}
|
|
|
|
static ssize_t red_zone_store(struct kmem_cache *s,
|
|
const char *buf, size_t length)
|
|
{
|
|
if (any_slab_objects(s))
|
|
return -EBUSY;
|
|
|
|
s->flags &= ~SLAB_RED_ZONE;
|
|
if (buf[0] == '1') {
|
|
s->flags &= ~__CMPXCHG_DOUBLE;
|
|
s->flags |= SLAB_RED_ZONE;
|
|
}
|
|
calculate_sizes(s, -1);
|
|
return length;
|
|
}
|
|
SLAB_ATTR(red_zone);
|
|
|
|
static ssize_t poison_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sprintf(buf, "%d\n", !!(s->flags & SLAB_POISON));
|
|
}
|
|
|
|
static ssize_t poison_store(struct kmem_cache *s,
|
|
const char *buf, size_t length)
|
|
{
|
|
if (any_slab_objects(s))
|
|
return -EBUSY;
|
|
|
|
s->flags &= ~SLAB_POISON;
|
|
if (buf[0] == '1') {
|
|
s->flags &= ~__CMPXCHG_DOUBLE;
|
|
s->flags |= SLAB_POISON;
|
|
}
|
|
calculate_sizes(s, -1);
|
|
return length;
|
|
}
|
|
SLAB_ATTR(poison);
|
|
|
|
static ssize_t store_user_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sprintf(buf, "%d\n", !!(s->flags & SLAB_STORE_USER));
|
|
}
|
|
|
|
static ssize_t store_user_store(struct kmem_cache *s,
|
|
const char *buf, size_t length)
|
|
{
|
|
if (any_slab_objects(s))
|
|
return -EBUSY;
|
|
|
|
s->flags &= ~SLAB_STORE_USER;
|
|
if (buf[0] == '1') {
|
|
s->flags &= ~__CMPXCHG_DOUBLE;
|
|
s->flags |= SLAB_STORE_USER;
|
|
}
|
|
calculate_sizes(s, -1);
|
|
return length;
|
|
}
|
|
SLAB_ATTR(store_user);
|
|
|
|
static ssize_t validate_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t validate_store(struct kmem_cache *s,
|
|
const char *buf, size_t length)
|
|
{
|
|
int ret = -EINVAL;
|
|
|
|
if (buf[0] == '1') {
|
|
ret = validate_slab_cache(s);
|
|
if (ret >= 0)
|
|
ret = length;
|
|
}
|
|
return ret;
|
|
}
|
|
SLAB_ATTR(validate);
|
|
|
|
static ssize_t alloc_calls_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
if (!(s->flags & SLAB_STORE_USER))
|
|
return -ENOSYS;
|
|
return list_locations(s, buf, TRACK_ALLOC);
|
|
}
|
|
SLAB_ATTR_RO(alloc_calls);
|
|
|
|
static ssize_t free_calls_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
if (!(s->flags & SLAB_STORE_USER))
|
|
return -ENOSYS;
|
|
return list_locations(s, buf, TRACK_FREE);
|
|
}
|
|
SLAB_ATTR_RO(free_calls);
|
|
#endif /* CONFIG_SLUB_DEBUG */
|
|
|
|
#ifdef CONFIG_FAILSLAB
|
|
static ssize_t failslab_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sprintf(buf, "%d\n", !!(s->flags & SLAB_FAILSLAB));
|
|
}
|
|
|
|
static ssize_t failslab_store(struct kmem_cache *s, const char *buf,
|
|
size_t length)
|
|
{
|
|
s->flags &= ~SLAB_FAILSLAB;
|
|
if (buf[0] == '1')
|
|
s->flags |= SLAB_FAILSLAB;
|
|
return length;
|
|
}
|
|
SLAB_ATTR(failslab);
|
|
#endif
|
|
|
|
static ssize_t shrink_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t shrink_store(struct kmem_cache *s,
|
|
const char *buf, size_t length)
|
|
{
|
|
if (buf[0] == '1') {
|
|
int rc = kmem_cache_shrink(s);
|
|
|
|
if (rc)
|
|
return rc;
|
|
} else
|
|
return -EINVAL;
|
|
return length;
|
|
}
|
|
SLAB_ATTR(shrink);
|
|
|
|
#ifdef CONFIG_NUMA
|
|
static ssize_t remote_node_defrag_ratio_show(struct kmem_cache *s, char *buf)
|
|
{
|
|
return sprintf(buf, "%d\n", s->remote_node_defrag_ratio / 10);
|
|
}
|
|
|
|
static ssize_t remote_node_defrag_ratio_store(struct kmem_cache *s,
|
|
const char *buf, size_t length)
|
|
{
|
|
unsigned long ratio;
|
|
int err;
|
|
|
|
err = strict_strtoul(buf, 10, &ratio);
|
|
if (err)
|
|
return err;
|
|
|
|
if (ratio <= 100)
|
|
s->remote_node_defrag_ratio = ratio * 10;
|
|
|
|
return length;
|
|
}
|
|
SLAB_ATTR(remote_node_defrag_ratio);
|
|
#endif
|
|
|
|
#ifdef CONFIG_SLUB_STATS
|
|
static int show_stat(struct kmem_cache *s, char *buf, enum stat_item si)
|
|
{
|
|
unsigned long sum = 0;
|
|
int cpu;
|
|
int len;
|
|
int *data = kmalloc(nr_cpu_ids * sizeof(int), GFP_KERNEL);
|
|
|
|
if (!data)
|
|
return -ENOMEM;
|
|
|
|
for_each_online_cpu(cpu) {
|
|
unsigned x = per_cpu_ptr(s->cpu_slab, cpu)->stat[si];
|
|
|
|
data[cpu] = x;
|
|
sum += x;
|
|
}
|
|
|
|
len = sprintf(buf, "%lu", sum);
|
|
|
|
#ifdef CONFIG_SMP
|
|
for_each_online_cpu(cpu) {
|
|
if (data[cpu] && len < PAGE_SIZE - 20)
|
|
len += sprintf(buf + len, " C%d=%u", cpu, data[cpu]);
|
|
}
|
|
#endif
|
|
kfree(data);
|
|
return len + sprintf(buf + len, "\n");
|
|
}
|
|
|
|
static void clear_stat(struct kmem_cache *s, enum stat_item si)
|
|
{
|
|
int cpu;
|
|
|
|
for_each_online_cpu(cpu)
|
|
per_cpu_ptr(s->cpu_slab, cpu)->stat[si] = 0;
|
|
}
|
|
|
|
#define STAT_ATTR(si, text) \
|
|
static ssize_t text##_show(struct kmem_cache *s, char *buf) \
|
|
{ \
|
|
return show_stat(s, buf, si); \
|
|
} \
|
|
static ssize_t text##_store(struct kmem_cache *s, \
|
|
const char *buf, size_t length) \
|
|
{ \
|
|
if (buf[0] != '0') \
|
|
return -EINVAL; \
|
|
clear_stat(s, si); \
|
|
return length; \
|
|
} \
|
|
SLAB_ATTR(text); \
|
|
|
|
STAT_ATTR(ALLOC_FASTPATH, alloc_fastpath);
|
|
STAT_ATTR(ALLOC_SLOWPATH, alloc_slowpath);
|
|
STAT_ATTR(FREE_FASTPATH, free_fastpath);
|
|
STAT_ATTR(FREE_SLOWPATH, free_slowpath);
|
|
STAT_ATTR(FREE_FROZEN, free_frozen);
|
|
STAT_ATTR(FREE_ADD_PARTIAL, free_add_partial);
|
|
STAT_ATTR(FREE_REMOVE_PARTIAL, free_remove_partial);
|
|
STAT_ATTR(ALLOC_FROM_PARTIAL, alloc_from_partial);
|
|
STAT_ATTR(ALLOC_SLAB, alloc_slab);
|
|
STAT_ATTR(ALLOC_REFILL, alloc_refill);
|
|
STAT_ATTR(ALLOC_NODE_MISMATCH, alloc_node_mismatch);
|
|
STAT_ATTR(FREE_SLAB, free_slab);
|
|
STAT_ATTR(CPUSLAB_FLUSH, cpuslab_flush);
|
|
STAT_ATTR(DEACTIVATE_FULL, deactivate_full);
|
|
STAT_ATTR(DEACTIVATE_EMPTY, deactivate_empty);
|
|
STAT_ATTR(DEACTIVATE_TO_HEAD, deactivate_to_head);
|
|
STAT_ATTR(DEACTIVATE_TO_TAIL, deactivate_to_tail);
|
|
STAT_ATTR(DEACTIVATE_REMOTE_FREES, deactivate_remote_frees);
|
|
STAT_ATTR(DEACTIVATE_BYPASS, deactivate_bypass);
|
|
STAT_ATTR(ORDER_FALLBACK, order_fallback);
|
|
STAT_ATTR(CMPXCHG_DOUBLE_CPU_FAIL, cmpxchg_double_cpu_fail);
|
|
STAT_ATTR(CMPXCHG_DOUBLE_FAIL, cmpxchg_double_fail);
|
|
STAT_ATTR(CPU_PARTIAL_ALLOC, cpu_partial_alloc);
|
|
STAT_ATTR(CPU_PARTIAL_FREE, cpu_partial_free);
|
|
#endif
|
|
|
|
static struct attribute *slab_attrs[] = {
|
|
&slab_size_attr.attr,
|
|
&object_size_attr.attr,
|
|
&objs_per_slab_attr.attr,
|
|
&order_attr.attr,
|
|
&min_partial_attr.attr,
|
|
&cpu_partial_attr.attr,
|
|
&objects_attr.attr,
|
|
&objects_partial_attr.attr,
|
|
&partial_attr.attr,
|
|
&cpu_slabs_attr.attr,
|
|
&ctor_attr.attr,
|
|
&aliases_attr.attr,
|
|
&align_attr.attr,
|
|
&hwcache_align_attr.attr,
|
|
&reclaim_account_attr.attr,
|
|
&destroy_by_rcu_attr.attr,
|
|
&shrink_attr.attr,
|
|
&reserved_attr.attr,
|
|
&slabs_cpu_partial_attr.attr,
|
|
#ifdef CONFIG_SLUB_DEBUG
|
|
&total_objects_attr.attr,
|
|
&slabs_attr.attr,
|
|
&sanity_checks_attr.attr,
|
|
&trace_attr.attr,
|
|
&red_zone_attr.attr,
|
|
&poison_attr.attr,
|
|
&store_user_attr.attr,
|
|
&validate_attr.attr,
|
|
&alloc_calls_attr.attr,
|
|
&free_calls_attr.attr,
|
|
#endif
|
|
#ifdef CONFIG_ZONE_DMA
|
|
&cache_dma_attr.attr,
|
|
#endif
|
|
#ifdef CONFIG_NUMA
|
|
&remote_node_defrag_ratio_attr.attr,
|
|
#endif
|
|
#ifdef CONFIG_SLUB_STATS
|
|
&alloc_fastpath_attr.attr,
|
|
&alloc_slowpath_attr.attr,
|
|
&free_fastpath_attr.attr,
|
|
&free_slowpath_attr.attr,
|
|
&free_frozen_attr.attr,
|
|
&free_add_partial_attr.attr,
|
|
&free_remove_partial_attr.attr,
|
|
&alloc_from_partial_attr.attr,
|
|
&alloc_slab_attr.attr,
|
|
&alloc_refill_attr.attr,
|
|
&alloc_node_mismatch_attr.attr,
|
|
&free_slab_attr.attr,
|
|
&cpuslab_flush_attr.attr,
|
|
&deactivate_full_attr.attr,
|
|
&deactivate_empty_attr.attr,
|
|
&deactivate_to_head_attr.attr,
|
|
&deactivate_to_tail_attr.attr,
|
|
&deactivate_remote_frees_attr.attr,
|
|
&deactivate_bypass_attr.attr,
|
|
&order_fallback_attr.attr,
|
|
&cmpxchg_double_fail_attr.attr,
|
|
&cmpxchg_double_cpu_fail_attr.attr,
|
|
&cpu_partial_alloc_attr.attr,
|
|
&cpu_partial_free_attr.attr,
|
|
#endif
|
|
#ifdef CONFIG_FAILSLAB
|
|
&failslab_attr.attr,
|
|
#endif
|
|
|
|
NULL
|
|
};
|
|
|
|
static struct attribute_group slab_attr_group = {
|
|
.attrs = slab_attrs,
|
|
};
|
|
|
|
static ssize_t slab_attr_show(struct kobject *kobj,
|
|
struct attribute *attr,
|
|
char *buf)
|
|
{
|
|
struct slab_attribute *attribute;
|
|
struct kmem_cache *s;
|
|
int err;
|
|
|
|
attribute = to_slab_attr(attr);
|
|
s = to_slab(kobj);
|
|
|
|
if (!attribute->show)
|
|
return -EIO;
|
|
|
|
err = attribute->show(s, buf);
|
|
|
|
return err;
|
|
}
|
|
|
|
static ssize_t slab_attr_store(struct kobject *kobj,
|
|
struct attribute *attr,
|
|
const char *buf, size_t len)
|
|
{
|
|
struct slab_attribute *attribute;
|
|
struct kmem_cache *s;
|
|
int err;
|
|
|
|
attribute = to_slab_attr(attr);
|
|
s = to_slab(kobj);
|
|
|
|
if (!attribute->store)
|
|
return -EIO;
|
|
|
|
err = attribute->store(s, buf, len);
|
|
|
|
return err;
|
|
}
|
|
|
|
static void kmem_cache_release(struct kobject *kobj)
|
|
{
|
|
struct kmem_cache *s = to_slab(kobj);
|
|
|
|
kfree(s->name);
|
|
kfree(s);
|
|
}
|
|
|
|
static const struct sysfs_ops slab_sysfs_ops = {
|
|
.show = slab_attr_show,
|
|
.store = slab_attr_store,
|
|
};
|
|
|
|
static struct kobj_type slab_ktype = {
|
|
.sysfs_ops = &slab_sysfs_ops,
|
|
.release = kmem_cache_release
|
|
};
|
|
|
|
static int uevent_filter(struct kset *kset, struct kobject *kobj)
|
|
{
|
|
struct kobj_type *ktype = get_ktype(kobj);
|
|
|
|
if (ktype == &slab_ktype)
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
static const struct kset_uevent_ops slab_uevent_ops = {
|
|
.filter = uevent_filter,
|
|
};
|
|
|
|
static struct kset *slab_kset;
|
|
|
|
#define ID_STR_LENGTH 64
|
|
|
|
/* Create a unique string id for a slab cache:
|
|
*
|
|
* Format :[flags-]size
|
|
*/
|
|
static char *create_unique_id(struct kmem_cache *s)
|
|
{
|
|
char *name = kmalloc(ID_STR_LENGTH, GFP_KERNEL);
|
|
char *p = name;
|
|
|
|
BUG_ON(!name);
|
|
|
|
*p++ = ':';
|
|
/*
|
|
* First flags affecting slabcache operations. We will only
|
|
* get here for aliasable slabs so we do not need to support
|
|
* too many flags. The flags here must cover all flags that
|
|
* are matched during merging to guarantee that the id is
|
|
* unique.
|
|
*/
|
|
if (s->flags & SLAB_CACHE_DMA)
|
|
*p++ = 'd';
|
|
if (s->flags & SLAB_RECLAIM_ACCOUNT)
|
|
*p++ = 'a';
|
|
if (s->flags & SLAB_DEBUG_FREE)
|
|
*p++ = 'F';
|
|
if (!(s->flags & SLAB_NOTRACK))
|
|
*p++ = 't';
|
|
if (p != name + 1)
|
|
*p++ = '-';
|
|
p += sprintf(p, "%07d", s->size);
|
|
BUG_ON(p > name + ID_STR_LENGTH - 1);
|
|
return name;
|
|
}
|
|
|
|
static int sysfs_slab_add(struct kmem_cache *s)
|
|
{
|
|
int err;
|
|
const char *name;
|
|
int unmergeable;
|
|
|
|
if (slab_state < SYSFS)
|
|
/* Defer until later */
|
|
return 0;
|
|
|
|
unmergeable = slab_unmergeable(s);
|
|
if (unmergeable) {
|
|
/*
|
|
* Slabcache can never be merged so we can use the name proper.
|
|
* This is typically the case for debug situations. In that
|
|
* case we can catch duplicate names easily.
|
|
*/
|
|
sysfs_remove_link(&slab_kset->kobj, s->name);
|
|
name = s->name;
|
|
} else {
|
|
/*
|
|
* Create a unique name for the slab as a target
|
|
* for the symlinks.
|
|
*/
|
|
name = create_unique_id(s);
|
|
}
|
|
|
|
s->kobj.kset = slab_kset;
|
|
err = kobject_init_and_add(&s->kobj, &slab_ktype, NULL, name);
|
|
if (err) {
|
|
kobject_put(&s->kobj);
|
|
return err;
|
|
}
|
|
|
|
err = sysfs_create_group(&s->kobj, &slab_attr_group);
|
|
if (err) {
|
|
kobject_del(&s->kobj);
|
|
kobject_put(&s->kobj);
|
|
return err;
|
|
}
|
|
kobject_uevent(&s->kobj, KOBJ_ADD);
|
|
if (!unmergeable) {
|
|
/* Setup first alias */
|
|
sysfs_slab_alias(s, s->name);
|
|
kfree(name);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static void sysfs_slab_remove(struct kmem_cache *s)
|
|
{
|
|
if (slab_state < SYSFS)
|
|
/*
|
|
* Sysfs has not been setup yet so no need to remove the
|
|
* cache from sysfs.
|
|
*/
|
|
return;
|
|
|
|
kobject_uevent(&s->kobj, KOBJ_REMOVE);
|
|
kobject_del(&s->kobj);
|
|
kobject_put(&s->kobj);
|
|
}
|
|
|
|
/*
|
|
* Need to buffer aliases during bootup until sysfs becomes
|
|
* available lest we lose that information.
|
|
*/
|
|
struct saved_alias {
|
|
struct kmem_cache *s;
|
|
const char *name;
|
|
struct saved_alias *next;
|
|
};
|
|
|
|
static struct saved_alias *alias_list;
|
|
|
|
static int sysfs_slab_alias(struct kmem_cache *s, const char *name)
|
|
{
|
|
struct saved_alias *al;
|
|
|
|
if (slab_state == SYSFS) {
|
|
/*
|
|
* If we have a leftover link then remove it.
|
|
*/
|
|
sysfs_remove_link(&slab_kset->kobj, name);
|
|
return sysfs_create_link(&slab_kset->kobj, &s->kobj, name);
|
|
}
|
|
|
|
al = kmalloc(sizeof(struct saved_alias), GFP_KERNEL);
|
|
if (!al)
|
|
return -ENOMEM;
|
|
|
|
al->s = s;
|
|
al->name = name;
|
|
al->next = alias_list;
|
|
alias_list = al;
|
|
return 0;
|
|
}
|
|
|
|
static int __init slab_sysfs_init(void)
|
|
{
|
|
struct kmem_cache *s;
|
|
int err;
|
|
|
|
down_write(&slub_lock);
|
|
|
|
slab_kset = kset_create_and_add("slab", &slab_uevent_ops, kernel_kobj);
|
|
if (!slab_kset) {
|
|
up_write(&slub_lock);
|
|
printk(KERN_ERR "Cannot register slab subsystem.\n");
|
|
return -ENOSYS;
|
|
}
|
|
|
|
slab_state = SYSFS;
|
|
|
|
list_for_each_entry(s, &slab_caches, list) {
|
|
err = sysfs_slab_add(s);
|
|
if (err)
|
|
printk(KERN_ERR "SLUB: Unable to add boot slab %s"
|
|
" to sysfs\n", s->name);
|
|
}
|
|
|
|
while (alias_list) {
|
|
struct saved_alias *al = alias_list;
|
|
|
|
alias_list = alias_list->next;
|
|
err = sysfs_slab_alias(al->s, al->name);
|
|
if (err)
|
|
printk(KERN_ERR "SLUB: Unable to add boot slab alias"
|
|
" %s to sysfs\n", s->name);
|
|
kfree(al);
|
|
}
|
|
|
|
up_write(&slub_lock);
|
|
resiliency_test();
|
|
return 0;
|
|
}
|
|
|
|
__initcall(slab_sysfs_init);
|
|
#endif /* CONFIG_SYSFS */
|
|
|
|
/*
|
|
* The /proc/slabinfo ABI
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*/
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#ifdef CONFIG_SLABINFO
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static void print_slabinfo_header(struct seq_file *m)
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{
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seq_puts(m, "slabinfo - version: 2.1\n");
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seq_puts(m, "# name <active_objs> <num_objs> <objsize> "
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"<objperslab> <pagesperslab>");
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seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>");
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seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
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seq_putc(m, '\n');
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}
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static void *s_start(struct seq_file *m, loff_t *pos)
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{
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loff_t n = *pos;
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down_read(&slub_lock);
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if (!n)
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print_slabinfo_header(m);
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return seq_list_start(&slab_caches, *pos);
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}
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static void *s_next(struct seq_file *m, void *p, loff_t *pos)
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{
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return seq_list_next(p, &slab_caches, pos);
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}
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static void s_stop(struct seq_file *m, void *p)
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{
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up_read(&slub_lock);
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}
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static int s_show(struct seq_file *m, void *p)
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{
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unsigned long nr_partials = 0;
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unsigned long nr_slabs = 0;
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unsigned long nr_inuse = 0;
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unsigned long nr_objs = 0;
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unsigned long nr_free = 0;
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struct kmem_cache *s;
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int node;
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s = list_entry(p, struct kmem_cache, list);
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for_each_online_node(node) {
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struct kmem_cache_node *n = get_node(s, node);
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if (!n)
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continue;
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nr_partials += n->nr_partial;
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nr_slabs += atomic_long_read(&n->nr_slabs);
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nr_objs += atomic_long_read(&n->total_objects);
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nr_free += count_partial(n, count_free);
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}
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nr_inuse = nr_objs - nr_free;
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seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d", s->name, nr_inuse,
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nr_objs, s->size, oo_objects(s->oo),
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(1 << oo_order(s->oo)));
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seq_printf(m, " : tunables %4u %4u %4u", 0, 0, 0);
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seq_printf(m, " : slabdata %6lu %6lu %6lu", nr_slabs, nr_slabs,
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0UL);
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seq_putc(m, '\n');
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return 0;
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}
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static const struct seq_operations slabinfo_op = {
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.start = s_start,
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.next = s_next,
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.stop = s_stop,
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.show = s_show,
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};
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static int slabinfo_open(struct inode *inode, struct file *file)
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{
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return seq_open(file, &slabinfo_op);
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}
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static const struct file_operations proc_slabinfo_operations = {
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.open = slabinfo_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = seq_release,
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};
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static int __init slab_proc_init(void)
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{
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proc_create("slabinfo", S_IRUSR, NULL, &proc_slabinfo_operations);
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return 0;
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}
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module_init(slab_proc_init);
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#endif /* CONFIG_SLABINFO */
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