memcg: make oom less frequently

In previous implementation, mem_cgroup_try_charge checked the return
value of mem_cgroup_try_to_free_pages, and just retried if some pages
had been reclaimed.
But now, try_charge(and mem_cgroup_hierarchical_reclaim called from it)
only checks whether the usage is less than the limit.

This patch tries to change the behavior as before to cause oom less
frequently.

Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Paul Menage <menage@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 2009-01-15 13:51:14 -08:00 committed by Linus Torvalds
parent c268e9946d
commit 4d1c627389

View File

@ -773,10 +773,10 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
* but there might be left over accounting, even after children
* have left.
*/
ret = try_to_free_mem_cgroup_pages(root_mem, gfp_mask, noswap,
ret += try_to_free_mem_cgroup_pages(root_mem, gfp_mask, noswap,
get_swappiness(root_mem));
if (mem_cgroup_check_under_limit(root_mem))
return 0;
return 1; /* indicate reclaim has succeeded */
if (!root_mem->use_hierarchy)
return ret;
@ -787,10 +787,10 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
next_mem = mem_cgroup_get_next_node(root_mem);
continue;
}
ret = try_to_free_mem_cgroup_pages(next_mem, gfp_mask, noswap,
ret += try_to_free_mem_cgroup_pages(next_mem, gfp_mask, noswap,
get_swappiness(next_mem));
if (mem_cgroup_check_under_limit(root_mem))
return 0;
return 1; /* indicate reclaim has succeeded */
next_mem = mem_cgroup_get_next_node(root_mem);
}
return ret;
@ -875,6 +875,8 @@ static int __mem_cgroup_try_charge(struct mm_struct *mm,
ret = mem_cgroup_hierarchical_reclaim(mem_over_limit, gfp_mask,
noswap);
if (ret)
continue;
/*
* try_to_free_mem_cgroup_pages() might not give us a full