The patch titled
Subject: fs/epoll: avoid barrier after an epoll_wait(2) timeout
has been removed from the -mm tree. Its filename was
fs-epoll-avoid-barrier-after-an-epoll_wait2-timeout.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Davidlohr Bueso <dave@xxxxxxxxxxxx>
Subject: fs/epoll: avoid barrier after an epoll_wait(2) timeout
Upon timeout, we can just exit out of the loop, without the cost of the
changing the task's state with an smp_store_mb call. Just exit out of the
loop and be done - setting the task state afterwards will be, of course,
redundant.
[dave@xxxxxxxxxxxx: forgotten fixlets]
Link: http://lkml.kernel.org/r/20181109155258.jxcr4t2pnz6zqct3@linux-r8p5
Link: http://lkml.kernel.org/r/20181108051006.18751-7-dave@xxxxxxxxxxxx
Signed-off-by: Davidlohr Bueso <dave@xxxxxxxxxxxx>
Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Davidlohr Bueso <dbueso@xxxxxxx>
Cc: Jason Baron <jbaron@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/eventpoll.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
--- a/fs/eventpoll.c~fs-epoll-avoid-barrier-after-an-epoll_wait2-timeout
+++ a/fs/eventpoll.c
@@ -1820,15 +1820,19 @@ fetch_events:
res = -EINTR;
break;
}
- if (ep_events_available(ep) || timed_out)
+
+ eavail = ep_events_available(ep);
+ if (eavail)
break;
if (signal_pending(current)) {
res = -EINTR;
break;
}
- if (!schedule_hrtimeout_range(to, slack, HRTIMER_MODE_ABS))
+ if (!schedule_hrtimeout_range(to, slack, HRTIMER_MODE_ABS)) {
timed_out = 1;
+ break;
+ }
}
__set_current_state(TASK_RUNNING);
_
Patches currently in -mm which might be from dave@xxxxxxxxxxxx are
