summaryrefslogtreecommitdiff
path: root/mm/page_alloc.c
diff options
context:
space:
mode:
authorKhazhismel Kumykov <khazhy@google.com>2020-05-07 18:35:59 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-05-14 07:58:26 +0200
commitee922a2f6be9fdf567dc357592155e6104f0a383 (patch)
treed6e484b8eae822a997741366f6a06a86bbebebf6 /mm/page_alloc.c
parent5d77631de15aff0fa65057cc542c5a3b874ca143 (diff)
eventpoll: fix missing wakeup for ovflist in ep_poll_callback
commit 0c54a6a44bf3d41e76ce3f583a6ece267618df2e upstream. In the event that we add to ovflist, before commit 339ddb53d373 ("fs/epoll: remove unnecessary wakeups of nested epoll") we would be woken up by ep_scan_ready_list, and did no wakeup in ep_poll_callback. With that wakeup removed, if we add to ovflist here, we may never wake up. Rather than adding back the ep_scan_ready_list wakeup - which was resulting in unnecessary wakeups, trigger a wake-up in ep_poll_callback. We noticed that one of our workloads was missing wakeups starting with 339ddb53d373 and upon manual inspection, this wakeup seemed missing to me. With this patch added, we no longer see missing wakeups. I haven't yet tried to make a small reproducer, but the existing kselftests in filesystem/epoll passed for me with this patch. [khazhy@google.com: use if/elif instead of goto + cleanup suggested by Roman] Link: http://lkml.kernel.org/r/20200424190039.192373-1-khazhy@google.com Fixes: 339ddb53d373 ("fs/epoll: remove unnecessary wakeups of nested epoll") Signed-off-by: Khazhismel Kumykov <khazhy@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Roman Penyaev <rpenyaev@suse.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Roman Penyaev <rpenyaev@suse.de> Cc: Heiher <r@hev.cc> Cc: Jason Baron <jbaron@akamai.com> Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/20200424025057.118641-1-khazhy@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'mm/page_alloc.c')
0 files changed, 0 insertions, 0 deletions