From mboxrd@z Thu Jan  1 00:00:00 1970
From: Michal =?iso-8859-1?Q?Koutn=FD?= <mkoutny@suse.com>
Subject: Re: [PATCH v8 0/6] cgroup/cpuset: Add new cpuset partition type &
 empty effecitve cpus
Date: Wed, 10 Nov 2021 14:56:53 +0100
Message-ID: <20211110135653.GD20566@blackbody.suse.cz>
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 <20211110111357.17617-1-felix.moessbauer@siemens.com>
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To: Felix Moessbauer <felix.moessbauer@siemens.com>
Cc: longman@redhat.com, akpm@linux-foundation.org, cgroups@vger.kernel.org, corbet@lwn.net, frederic@kernel.org, guro@fb.com, hannes@cmpxchg.org, juri.lelli@redhat.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, lizefan.x@bytedance.com, mtosatti@redhat.com, pauld@redhat.com, peterz@infradead.org, shuah@kernel.org, tj@kernel.org, jan.kiszka@siemens.com, henning.schild@siemens.com

Hello.

On Wed, Nov 10, 2021 at 12:13:57PM +0100, Felix Moessbauer <felix.moessbauer@siemens.com> wrote:
> However, I was not able to see any latency improvements when using
> cpuset.cpus.partition=isolated.

Interesting. What was the baseline against which you compared it
(isolcpus, no cpusets,...)?

> The test was performed with jitterdebugger on CPUs 1-3 and the following cmdline:
> rcu_nocbs=1-4 nohz_full=1-4 irqaffinity=0,5-6,11 intel_pstate=disable
> On the other cpus, stress-ng was executed to generate load.
> [...]

> This requires cgroup.type=threaded on both cgroups and changes to the application
> (threads have to be born in non-rt group and moved to rt-group).

But even with isolcpus the application would need to set affinity of
threads to the selected CPUs (cf cgroup migrating). Do I miss anything?

Thanks,
Michal