[PATCH] cgroup: restore the call to eventfd->poll()

[PATCH] cgroup: restore the call to eventfd->poll()

[Li Zefan]

I mistakenly removed the call to eventfd->poll() while I was actually
intending to remove the return value...

Calling evenfd->poll() will hook cgroup_event_wake() to the poll
waitqueue, which will be called to unregister eventfd when rmdir a
cgroup or close eventfd.

Signed-off-by: Li Zefan <lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
---
 kernel/cgroup.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index a45aa12..4b0f2ef 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -3882,6 +3882,8 @@ static int cgroup_write_event_control(struct cgroup *cgrp, struct cftype *cft,
 	if (ret)
 		goto fail;
 
+	efile->f_op->poll(efile, &event->pt);
+
 	/*
 	 * Events should be removed after rmdir of cgroup directory, but before
 	 * destroying subsystem state objects. Let's take reference to cgroup
-- 
1.8.0.2

Re: [PATCH] cgroup: restore the call to eventfd->poll()

[Tejun Heo]

On Fri, Apr 26, 2013 at 10:54:52AM +0800, Li Zefan wrote:
> I mistakenly removed the call to eventfd->poll() while I was actually
> intending to remove the return value...
> 
> Calling evenfd->poll() will hook cgroup_event_wake() to the poll
> waitqueue, which will be called to unregister eventfd when rmdir a
> cgroup or close eventfd.
> 
> Signed-off-by: Li Zefan <lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>

Applied to cgroup/for-3.10.  It'd have been better if the patch
description pointed to the specific commit which caused the problem.

Thanks.

-- 
tejun