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memcg: fix mem_cgroup_shrink_usage() 

Current mem_cgroup_shrink_usage() has two problems.

1. It doesn't call mem_cgroup_out_of_memory and doesn't update
   last_oom_jiffies, so pagefault_out_of_memory invokes global OOM.

2. Considering hierarchy, shrinking has to be done from the
   mem_over_limit, not from the memcg which the page would be charged to.

mem_cgroup_try_charge_swapin() does all of these things properly, so we
use it and call cancel_charge_swapin when it succeeded.

The name of "shrink_usage" is not appropriate for this behavior, so we
change it too.

Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.cn>
Cc: Paul Menage <menage@google.com>
Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Daisuke Nishimura 2009-04-30 15:08:19 -07:00 committed by Linus Torvalds
parent 0816178638
commit ae3abae64f
3 changed files with 20 additions and 25 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
include/linux/memcontrol.h
View File

@ -56,7 +56,7 @@ extern void mem_cgroup_move_lists(struct page *page,
enum lru_list from, enum lru_list to);
extern void mem_cgroup_uncharge_page(struct page *page);
extern void mem_cgroup_uncharge_cache_page(struct page *page);
extern int mem_cgroup_shrink_usage(struct page *page,
extern int mem_cgroup_shmem_charge_fallback(struct page *page,
struct mm_struct *mm, gfp_t gfp_mask);
extern unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
@ -155,7 +155,7 @@ static inline void mem_cgroup_uncharge_cache_page(struct page *page)
{
}
static inline int mem_cgroup_shrink_usage(struct page *page,
static inline int mem_cgroup_shmem_charge_fallback(struct page *page,
struct mm_struct *mm, gfp_t gfp_mask)
{
return 0;

33
mm/memcontrol.c
View File

@ -1617,37 +1617,28 @@ void mem_cgroup_end_migration(struct mem_cgroup *mem,
}
/*
* A call to try to shrink memory usage under specified resource controller.
* This is typically used for page reclaiming for shmem for reducing side
* effect of page allocation from shmem, which is used by some mem_cgroup.
* A call to try to shrink memory usage on charge failure at shmem's swapin.
* Calling hierarchical_reclaim is not enough because we should update
* last_oom_jiffies to prevent pagefault_out_of_memory from invoking global OOM.
* Moreover considering hierarchy, we should reclaim from the mem_over_limit,
* not from the memcg which this page would be charged to.
* try_charge_swapin does all of these works properly.
*/
int mem_cgroup_shrink_usage(struct page *page,
int mem_cgroup_shmem_charge_fallback(struct page *page,
struct mm_struct *mm,
gfp_t gfp_mask)
{
struct mem_cgroup *mem = NULL;
int progress = 0;
int retry = MEM_CGROUP_RECLAIM_RETRIES;
int ret;
if (mem_cgroup_disabled())
return 0;
if (page)
mem = try_get_mem_cgroup_from_swapcache(page);
if (!mem && mm)
mem = try_get_mem_cgroup_from_mm(mm);
if (unlikely(!mem))
return 0;
do {
progress = mem_cgroup_hierarchical_reclaim(mem,
gfp_mask, true, false);
progress += mem_cgroup_check_under_limit(mem);
} while (!progress && --retry);
ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem);
if (!ret)
mem_cgroup_cancel_charge_swapin(mem); /* it does !mem check */
css_put(&mem->css);
if (!retry)
return -ENOMEM;
return 0;
return ret;
}
static DEFINE_MUTEX(set_limit_mutex);

8
mm/shmem.c
View File

@ -1340,8 +1340,12 @@ static int shmem_getpage(struct inode *inode, unsigned long idx,
shmem_swp_unmap(entry);
spin_unlock(&info->lock);
if (error == -ENOMEM) {
/* allow reclaim from this memory cgroup */
error = mem_cgroup_shrink_usage(swappage,
/*
* reclaim from proper memory cgroup and
* call memcg's OOM if needed.
*/
error = mem_cgroup_shmem_charge_fallback(
swappage,
current->mm,
gfp);
if (error) {