From: Wanpeng Li <liwp@xxxxxxxxxxxxxxxxxx> Function mem_cgroup_do_charge will call mem_cgroup_reclaim, there are two break points in mem_cgroup_reclaim: if (total && (flag & MEM_CGROUP_RECLAIM_SHIRINK)) break; if (mem_cgroup_margin(memcg)) break; so mem_cgroup_reclaim can't guarantee reclaim enough pages(nr_pages) which is requested from mem_cgroup_do_charge, if mem_cgroup_margin (mem_over_limit) >= nr_pages is not true, the process will go to mem_cgroup_wait_acct_move to wait doubly charge counted caused by task move. But this time still can't guarantee enough pages(nr_pages) is ready, directly return CHARGE_RETRY is incorret. We should add a check to confirm enough pages is ready, otherwise go to oom. Signed-off-by: Wanpeng Li <liwp.linux@xxxxxxxxx> --- mm/memcontrol.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index f72b5e5..4ae3848 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2210,7 +2210,8 @@ static int mem_cgroup_do_charge(struct mem_cgroup *memcg, gfp_t gfp_mask, * At task move, charge accounts can be doubly counted. So, it's * better to wait until the end of task_move if something is going on. */ - if (mem_cgroup_wait_acct_move(mem_over_limit)) + if (mem_cgroup_wait_acct_move(mem_over_limit) + && mem_cgroup_margin(mem_over_limit) >= nr_pages) return CHARGE_RETRY; /* If we don't need to call oom-killer at el, return immediately */ -- 1.7.5.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>