linux-kernel - Re: [PATCH 1/2] cgroup: pids: show number of failed forks since limit reset

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Message-ID: <20160626234258.GJ9219@stj.duckdns.org>
Date:	Sun, 26 Jun 2016 19:42:58 -0400
From:	Tejun Heo <tj@...nel.org>
To:	Aleksa Sarai <asarai@...e.de>
Cc:	Jonathan Corbet <corbet@....net>, Li Zefan <lizefan@...wei.com>,
	Johannes Weiner <hannes@...xchg.org>,
	Kenny Yu <kennyyu@...com>, linux-doc@...r.kernel.org,
	linux-kernel@...r.kernel.org, cgroups@...r.kernel.org
Subject: Re: [PATCH 1/2] cgroup: pids: show number of failed forks since
 limit reset

Hello,

On Sun, Jun 26, 2016 at 09:34:41PM +1000, Aleksa Sarai wrote:
> If a user has a setup where they wait for notifications on changes to
> pids.event, and then auto-adjust the cgroup limits based on the number of
> failures you have a race condition between reading the pids.event file and
> then setting the new limit. Then, upon getting notified again there may have
> been many failed forks with the old limit set, so you might decide to bump
> up the limit again.
> 
> It's not a huge deal, I just though it could be useful to alleviate problems
> like the above.

This is something which can easily be avoided from userland.  I don't
think we need to add extra facilities for this.

Thanks.

-- 
tejun