memcg, oom: no oom-kill for __GFP_RETRY_MAYFAIL

The documentation of __GFP_RETRY_MAYFAIL clearly mentioned that the OOM
killer will not be triggered and indeed the page alloc does not invoke OOM
killer for such allocations.  However we do trigger memcg OOM killer for
__GFP_RETRY_MAYFAIL.  Fix that.  This flag will used later to not trigger
oom-killer in the charging path for fanotify and inotify event
allocations.

Link: http://lkml.kernel.org/r/20190514212259.156585-1-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 591eafafbd8cb85fd0d04dc539e692053184e86c..2ad94d0ce22fb0e303498f1293d269fa2f33b521 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2279,7 +2279,6 @@ static int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
        unsigned long nr_reclaimed;
        bool may_swap = true;
        bool drained = false;
-       bool oomed = false;
        enum oom_status oom_status;
 
        if (mem_cgroup_is_root(memcg))
@@ -2366,7 +2365,7 @@ retry:
        if (nr_retries--)
                goto retry;
 
-       if (gfp_mask & __GFP_RETRY_MAYFAIL && oomed)
+       if (gfp_mask & __GFP_RETRY_MAYFAIL)
                goto nomem;
 
        if (gfp_mask & __GFP_NOFAIL)
@@ -2385,7 +2384,6 @@ retry:
        switch (oom_status) {
        case OOM_SUCCESS:
                nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
-               oomed = true;
                goto retry;
        case OOM_FAILED:
                goto force;