Re: [PATCH v8 0/6] cgroup/cpuset: Add new cpuset partition type & empty effecitve cpus

From: Michal Koutný
Date: Wed Nov 10 2021 - 08:57:03 EST


Hello.

On Wed, Nov 10, 2021 at 12:13:57PM +0100, Felix Moessbauer <felix.moessbauer@xxxxxxxxxxx> 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