Commit ae3abae6 authored by Daisuke Nishimura's avatar Daisuke Nishimura Committed by Linus Torvalds

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: default avatarDaisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Acked-by: default avatarKAMEZAWA 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 08161786
...@@ -56,7 +56,7 @@ extern void mem_cgroup_move_lists(struct page *page, ...@@ -56,7 +56,7 @@ extern void mem_cgroup_move_lists(struct page *page,
enum lru_list from, enum lru_list to); enum lru_list from, enum lru_list to);
extern void mem_cgroup_uncharge_page(struct page *page); extern void mem_cgroup_uncharge_page(struct page *page);
extern void mem_cgroup_uncharge_cache_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); struct mm_struct *mm, gfp_t gfp_mask);
extern unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan, 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) ...@@ -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) struct mm_struct *mm, gfp_t gfp_mask)
{ {
return 0; return 0;
......
...@@ -1617,37 +1617,28 @@ void mem_cgroup_end_migration(struct mem_cgroup *mem, ...@@ -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. * A call to try to shrink memory usage on charge failure at shmem's swapin.
* This is typically used for page reclaiming for shmem for reducing side * Calling hierarchical_reclaim is not enough because we should update
* effect of page allocation from shmem, which is used by some mem_cgroup. * 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, struct mm_struct *mm,
gfp_t gfp_mask) gfp_t gfp_mask)
{ {
struct mem_cgroup *mem = NULL; struct mem_cgroup *mem = NULL;
int progress = 0; int ret;
int retry = MEM_CGROUP_RECLAIM_RETRIES;
if (mem_cgroup_disabled()) if (mem_cgroup_disabled())
return 0; 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 { ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem);
progress = mem_cgroup_hierarchical_reclaim(mem, if (!ret)
gfp_mask, true, false); mem_cgroup_cancel_charge_swapin(mem); /* it does !mem check */
progress += mem_cgroup_check_under_limit(mem);
} while (!progress && --retry);
css_put(&mem->css); return ret;
if (!retry)
return -ENOMEM;
return 0;
} }
static DEFINE_MUTEX(set_limit_mutex); static DEFINE_MUTEX(set_limit_mutex);
......
...@@ -1340,8 +1340,12 @@ static int shmem_getpage(struct inode *inode, unsigned long idx, ...@@ -1340,8 +1340,12 @@ static int shmem_getpage(struct inode *inode, unsigned long idx,
shmem_swp_unmap(entry); shmem_swp_unmap(entry);
spin_unlock(&info->lock); spin_unlock(&info->lock);
if (error == -ENOMEM) { 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, current->mm,
gfp); gfp);
if (error) { if (error) {
......
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