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From: Tejun Heo <tj@kernel.org>
To: Kenny Yu <kennyyu@fb.com>
Cc: "lizefan@huawei.com" <lizefan@huawei.com>,
	"hannes@cmpxchg.org" <hannes@cmpxchg.org>,
	"cyphar@cyphar.com" <cyphar@cyphar.com>,
	"cgroups@vger.kernel.org" <cgroups@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Kernel Team <Kernel-team@fb.com>
Subject: Re: [PATCH v3] cgroup: Add pids controller event when fork fails because of pid limit
Date: Tue, 21 Jun 2016 13:28:32 -0400	[thread overview]
Message-ID: <20160621172832.GM3262@mtj.duckdns.org> (raw)
In-Reply-To: <9874B6F0-99B8-4739-B099-B7EEE99478F3@fb.com>

Hello,

On Tue, Jun 21, 2016 at 05:23:40PM +0000, Kenny Yu wrote:
> >It'd be better to use atomic64_inc_and_test() instead.
> >
> >	if (err) {
> >		if (atomic64_inc_and_test()) {
> >			pr_xxx...;
> >		}
> >		cgroup_file_notify(&pids->events_file);
> >	}
> >
> 
> According to the docs https://www.kernel.org/doc/Documentation/atomic_ops.txt ,
> it looks like atomic_inc_and_test returns "a boolean indicating whether the resulting
> counter value was zero or not", which will only happen when the counter goes from
> negative to 0. I'll keep it as atomic_inc_return and get rid of the temp variable.

Right you're.  Sorry about the confusion.  Yeah, that sounds good to
me.

Thanks!

-- 
tejun

  reply	other threads:[~2016-06-21 18:23 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-06-21  3:09 [PATCH] cgroup: Add pids controller event when fork fails because of pid limit Kenny Yu
2016-06-21  4:44 ` Johannes Weiner
2016-06-21 16:01   ` [PATCH v2] " Kenny Yu
2016-06-21 16:07     ` Aleksa Sarai
2016-06-21 16:34       ` Tejun Heo
2016-06-21 16:56         ` [PATCH v3] " Kenny Yu
2016-06-21 17:12           ` Tejun Heo
2016-06-21 17:23             ` Kenny Yu
2016-06-21 17:28               ` Tejun Heo [this message]
2016-06-21 17:44                 ` [PATCH v4] " Kenny Yu
2016-06-21 18:06                   ` Tejun Heo

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