3.12-stable review patch. If anyone has any objections, please let me know.
------------------ From: Johannes Weiner <[email protected]> commit a0d8b00a3381f9d75764b3377590451cb0b4fe41 upstream. Commit 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 <[email protected]> Signed-off-by: Johannes Weiner <[email protected]> Acked-by: Michal Hocko <[email protected]> Cc: David Rientjes <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- mm/memcontrol.c | 3 +++ 1 file changed, 3 insertions(+) --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2677,6 +2677,9 @@ static int __mem_cgroup_try_charge(struc 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
