From mboxrd@z Thu Jan  1 00:00:00 1970
From: Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Subject: Re: [PATCH cgroup/for-5.8] cgroup: add cpu.stat file to root cgroup
Date: Tue, 26 May 2020 16:15:54 -0400
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To: Boris Burkov <boris-UrQYPotlwNs@public.gmane.org>
Cc: Li Zefan <lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>, Johannes Weiner <hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org>, Ingo Molnar <mingo-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>, Peter Zijlstra <peterz-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>, Juri Lelli <juri.lelli-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>, Vincent Guittot <vincent.guittot-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, kernel-team-b10kYP2dOMg@public.gmane.org

Hello,

On Tue, May 26, 2020 at 01:08:00PM -0700, Boris Burkov wrote:
> Currently, the root cgroup does not have a cpu.stat file. Add one which
> is consistent with /proc/stat to capture global cpu statistics that
> might not fall under cgroup accounting.
> 
> We haven't done this in the past because the data are already presented
> in /proc/stat and we didn't want to add overhead from collecting root
> cgroup stats when cgroups are configured, but no cgroups have been
> created.
> 
> By keeping the data consistent with /proc/stat, I think we avoid the
> first problem, while improving the usability of cgroups stats.
> We avoid the second problem by computing the contents of cpu.stat from
> existing data collected for /proc/stat anyway.
> 
> Signed-off-by: Boris Burkov <boris-UrQYPotlwNs@public.gmane.org>
> Suggested-by: Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>

If there are any objections, please holler. I'll wait a few days and
route it through the cgroup tree.

Thanks.

-- 
tejun