From: Tejun Heo <tj@kernel.org>
To: lizefan@huawei.com, hannes@cmpxchg.org
Cc: cgroups@vger.kernel.org, linux-kernel@vger.kernel.org,
guro@fb.com, kernel-team@fb.com
Subject: Re: [PATCH] cgroup: Make cgroup_rstat_updated() ready for root cgroup usage
Date: Thu, 26 Apr 2018 14:36:27 -0700 [thread overview]
Message-ID: <20180426213627.GX1911913@devbig577.frc2.facebook.com> (raw)
In-Reply-To: <20180402214913.GH388343@devbig577.frc2.facebook.com>
On Mon, Apr 02, 2018 at 02:49:13PM -0700, Tejun Heo wrote:
> From b7be022bf811d02605098fa61b7545bc146b78e7 Mon Sep 17 00:00:00 2001
> From: Tejun Heo <tj@kernel.org>
> Date: Mon, 2 Apr 2018 14:45:20 -0700
>
> cgroup_rstat_updated() ensures that the cgroup's rstat is linked to
> the parent. If there's no parent, it never gets linked and the
> function ends up grabbing and releasing the cgroup_rstat_lock each
> time for no reason which can be expensive.
>
> This hasn't been a problem till now because nobody was calling the
> function for the root cgroup but rstat is gonna be exposed to
> controllers and use cases, so let's get ready. Make
> cgroup_rstat_updated() an no-op for the root cgroup.
>
> Signed-off-by: Tejun Heo <tj@kernel.org>
Applied to cgroup/for-4.18.
Thanks.
--
tejun
next prev parent reply other threads:[~2018-04-26 21:36 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-23 23:13 [PATCHSET] cgroup/for-4.17: Make cgroup_rstat available to controllers Tejun Heo
2018-03-23 23:13 ` [PATCH 1/8] cgroup: Rename kernel/cgroup/stat.c to kernel/cgroup/rstat.c Tejun Heo
2018-03-23 23:13 ` [PATCH 2/8] cgroup: Rename stat to rstat Tejun Heo
2018-03-23 23:13 ` [PATCH 3/8] cgroup: Distinguish base resource stat implementation from rstat Tejun Heo
2018-03-23 23:13 ` [PATCH 4/8] cgroup: Reorganize kernel/cgroup/rstat.c Tejun Heo
2018-03-23 23:13 ` [PATCH 5/8] cgroup: Factor out and expose cgroup_rstat_*() interface functions Tejun Heo
2018-03-24 20:44 ` [PATCH v2 " Tejun Heo
2018-03-23 23:13 ` [PATCH 6/8] cgroup: Replace cgroup_rstat_mutex with a spinlock Tejun Heo
2018-03-23 23:13 ` [PATCH 7/8] cgroup: Add cgroup_subsys->css_rstat_flush() Tejun Heo
2018-03-23 23:13 ` [PATCH 8/8] cgroup: Add memory barriers to plug cgroup_rstat_updated() race window Tejun Heo
2018-04-02 21:49 ` [PATCH] cgroup: Make cgroup_rstat_updated() ready for root cgroup usage Tejun Heo
2018-04-26 21:36 ` Tejun Heo [this message]
2018-04-26 21:35 ` [PATCHSET] cgroup/for-4.17: Make cgroup_rstat available to controllers Tejun Heo
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