a3b2d69269
Try to use CSS ID for records in swap_cgroup. By this, on 64bit machine,
size of swap_cgroup goes down to 2 bytes from 8bytes.
This means, when 2GB of swap is equipped, (assume the page size is 4096bytes)
From size of swap_cgroup = 2G/4k * 8 = 4Mbytes.
To size of swap_cgroup = 2G/4k * 2 = 1Mbytes.
Reduction is large. Of course, there are trade-offs. This CSS ID will
add overhead to swap-in/swap-out/swap-free.
But in general,
- swap is a resource which the user tend to avoid use.
- If swap is never used, swap_cgroup area is not used.
- Reading traditional manuals, size of swap should be proportional to
size of memory. Memory size of machine is increasing now.
I think reducing size of swap_cgroup makes sense.
Note:
- ID->CSS lookup routine has no locks, it's under RCU-Read-Side.
- memcg can be obsolete at rmdir() but not freed while refcnt from
swap_cgroup is available.
Changelog v4->v5:
- reworked on to memcg-charge-swapcache-to-proper-memcg.patch
Changlog ->v4:
- fixed not configured case.
- deleted unnecessary comments.
- fixed NULL pointer bug.
- fixed message in dmesg.
[nishimura@mxp.nes.nec.co.jp: css_tryget can be called twice in !PageCgroupUsed case]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Paul Menage <menage@google.com>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
125 lines
2.9 KiB
C
125 lines
2.9 KiB
C
#ifndef __LINUX_PAGE_CGROUP_H
|
|
#define __LINUX_PAGE_CGROUP_H
|
|
|
|
#ifdef CONFIG_CGROUP_MEM_RES_CTLR
|
|
#include <linux/bit_spinlock.h>
|
|
/*
|
|
* Page Cgroup can be considered as an extended mem_map.
|
|
* A page_cgroup page is associated with every page descriptor. The
|
|
* page_cgroup helps us identify information about the cgroup
|
|
* All page cgroups are allocated at boot or memory hotplug event,
|
|
* then the page cgroup for pfn always exists.
|
|
*/
|
|
struct page_cgroup {
|
|
unsigned long flags;
|
|
struct mem_cgroup *mem_cgroup;
|
|
struct page *page;
|
|
struct list_head lru; /* per cgroup LRU list */
|
|
};
|
|
|
|
void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat);
|
|
void __init page_cgroup_init(void);
|
|
struct page_cgroup *lookup_page_cgroup(struct page *page);
|
|
|
|
enum {
|
|
/* flags for mem_cgroup */
|
|
PCG_LOCK, /* page cgroup is locked */
|
|
PCG_CACHE, /* charged as cache */
|
|
PCG_USED, /* this object is in use. */
|
|
};
|
|
|
|
#define TESTPCGFLAG(uname, lname) \
|
|
static inline int PageCgroup##uname(struct page_cgroup *pc) \
|
|
{ return test_bit(PCG_##lname, &pc->flags); }
|
|
|
|
#define SETPCGFLAG(uname, lname) \
|
|
static inline void SetPageCgroup##uname(struct page_cgroup *pc)\
|
|
{ set_bit(PCG_##lname, &pc->flags); }
|
|
|
|
#define CLEARPCGFLAG(uname, lname) \
|
|
static inline void ClearPageCgroup##uname(struct page_cgroup *pc) \
|
|
{ clear_bit(PCG_##lname, &pc->flags); }
|
|
|
|
/* Cache flag is set only once (at allocation) */
|
|
TESTPCGFLAG(Cache, CACHE)
|
|
|
|
TESTPCGFLAG(Used, USED)
|
|
CLEARPCGFLAG(Used, USED)
|
|
|
|
static inline int page_cgroup_nid(struct page_cgroup *pc)
|
|
{
|
|
return page_to_nid(pc->page);
|
|
}
|
|
|
|
static inline enum zone_type page_cgroup_zid(struct page_cgroup *pc)
|
|
{
|
|
return page_zonenum(pc->page);
|
|
}
|
|
|
|
static inline void lock_page_cgroup(struct page_cgroup *pc)
|
|
{
|
|
bit_spin_lock(PCG_LOCK, &pc->flags);
|
|
}
|
|
|
|
static inline int trylock_page_cgroup(struct page_cgroup *pc)
|
|
{
|
|
return bit_spin_trylock(PCG_LOCK, &pc->flags);
|
|
}
|
|
|
|
static inline void unlock_page_cgroup(struct page_cgroup *pc)
|
|
{
|
|
bit_spin_unlock(PCG_LOCK, &pc->flags);
|
|
}
|
|
|
|
#else /* CONFIG_CGROUP_MEM_RES_CTLR */
|
|
struct page_cgroup;
|
|
|
|
static inline void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat)
|
|
{
|
|
}
|
|
|
|
static inline struct page_cgroup *lookup_page_cgroup(struct page *page)
|
|
{
|
|
return NULL;
|
|
}
|
|
|
|
static inline void page_cgroup_init(void)
|
|
{
|
|
}
|
|
|
|
#endif
|
|
|
|
#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
|
|
#include <linux/swap.h>
|
|
extern unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id);
|
|
extern unsigned short lookup_swap_cgroup(swp_entry_t ent);
|
|
extern int swap_cgroup_swapon(int type, unsigned long max_pages);
|
|
extern void swap_cgroup_swapoff(int type);
|
|
#else
|
|
#include <linux/swap.h>
|
|
|
|
static inline
|
|
unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline
|
|
unsigned short lookup_swap_cgroup(swp_entry_t ent)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline int
|
|
swap_cgroup_swapon(int type, unsigned long max_pages)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline void swap_cgroup_swapoff(int type)
|
|
{
|
|
return;
|
|
}
|
|
|
|
#endif
|
|
#endif
|