From a10cebf56ca7e7c034d1b6646230c6553e478967 Mon Sep 17 00:00:00 2001 From: Daisuke Nishimura Date: Mon, 22 Sep 2008 13:57:52 -0700 Subject: [PATCH] memcg: check under limit at shrink_usage Current memory cgroup(both in mainline and -mm) doesn't account swap caches as memory(swap cache support is dropped temporarily now). So try_to_free_mem_cgroup_pages doesn't reflect the count of pages that have been moved to swap cache. But this makes mem_cgroup_shrink_usage fail easily if most of the pages are anon/shmem, and then shmem_getpage returns -ENOMEM and the process will be killed. This patch adds res_counter_check_under_limit to avoid these cases. BTW, even if swap cache support is enabled again, if a process is moved to another cgroup, which has been just made, between precharge and shrink_usage in shmem_getpage, shrink_usage may fail just because there is no pages to reclaim. So this change would make sense anyway. Signed-off-by: Daisuke Nishimura Cc: Balbir Singh Cc: Pavel Emelyanov Cc: KAMEZAWA Hiroyuki Cc: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memcontrol.c | 1 + 1 file changed, 1 insertion(+) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 0f1f7a7374ba..c0500e4d3a2f 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -806,6 +806,7 @@ int mem_cgroup_shrink_usage(struct mm_struct *mm, gfp_t gfp_mask) do { progress = try_to_free_mem_cgroup_pages(mem, gfp_mask); + progress += res_counter_check_under_limit(&mem->res); } while (!progress && --retry); css_put(&mem->css); -- 2.30.2