84235de394d9 ("fs: buffer: move allocation failure loop into the allocator") started recognizing __GFP_NOFAIL in memory cgroups but forgot to disable the OOM killer.
Any task that does not fail allocation will also not enter the OOM completion path. So don't declare an OOM state in this case or it'll be leaked and the task be able to bypass the limit until the next userspace-triggered page fault cleans up the OOM state. Reported-by: William Dauchy <wdau...@gmail.com> Signed-off-by: Johannes Weiner <han...@cmpxchg.org> Cc: sta...@kernel.org # 3.12 --- mm/memcontrol.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 13b9d0f..cc4f9cb 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2677,6 +2677,9 @@ static int __mem_cgroup_try_charge(struct mm_struct *mm, if (unlikely(task_in_memcg_oom(current))) goto bypass; + if (gfp_mask & __GFP_NOFAIL) + oom = false; + /* * We always charge the cgroup the mm_struct belongs to. * The mm_struct's mem_cgroup changes on task migration if the -- 1.8.4.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/