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From: Tejun Heo <tj@kernel.org>
To: Shakeel Butt <shakeelb@google.com>
Cc: "Michal Koutný" <mkoutny@suse.com>,
	cgroups@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 3/3] cgroup: no need for cgroup_mutex for /proc/cgroups
Date: Mon, 25 Oct 2021 07:27:02 -1000	[thread overview]
Message-ID: <YXbo5sKj0wgPTaMp@slm.duckdns.org> (raw)
In-Reply-To: <20211025061916.3853623-3-shakeelb@google.com>

On Sun, Oct 24, 2021 at 11:19:16PM -0700, Shakeel Butt wrote:
> On the real systems, the cgroups hierarchies are setup early and just
> once by the node controller, so, other than number of cgroups, all
> information in /proc/cgroups remain same for the system uptime. Let's
> remove the cgroup_mutex usage on reading /proc/cgroups. There is a
> chance of inconsistent number of cgroups for co-mounted cgroups while
> printing the information from /proc/cgroups but that is not a big
> issue. In addition /proc/cgroups is a v1 specific interface, so the
> dependency on it should reduce over time.
> 
> The main motivation for removing the cgroup_mutex from /proc/cgroups is
> to reduce the avenues of its contention. On our fleet, we have observed
> buggy application hammering on /proc/cgroups and drastically slowing
> down the node controller on the system which have many negative
> consequences on other workloads running on the system.
> 
> Signed-off-by: Shakeel Butt <shakeelb@google.com>

Applied 1-3 to cgroup/for-5.16.

Thanks.

-- 
tejun

      reply	other threads:[~2021-10-25 17:27 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-10-25  6:19 [PATCH 1/3] cgroup: reduce dependency on cgroup_mutex Shakeel Butt
2021-10-25  6:19 ` Shakeel Butt
2021-10-25  6:19 ` [PATCH 2/3] cgroup: remove cgroup_mutex from cgroupstats_build Shakeel Butt
2021-10-25  6:19   ` Shakeel Butt
2021-10-25  6:19 ` [PATCH 3/3] cgroup: no need for cgroup_mutex for /proc/cgroups Shakeel Butt
2021-10-25  6:19   ` Shakeel Butt
2021-10-25 17:27   ` Tejun Heo [this message]

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