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Date:   Wed, 3 Mar 2021 16:32:18 +0100
From:   Peter Zijlstra <peterz@infradead.org>
To:     Johannes Weiner <hannes@cmpxchg.org>
Cc:     Chengming Zhou <zhouchengming@bytedance.com>, mingo@redhat.com,
        juri.lelli@redhat.com, vincent.guittot@linaro.org,
        dietmar.eggemann@arm.com, rostedt@goodmis.org,
        linux-kernel@vger.kernel.org, songmuchun@bytedance.com
Subject: Re: [PATCH v2 0/4] psi: Add PSI_CPU_FULL state and some code
 optimization
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References: <20210303034659.91735-1-zhouchengming@bytedance.com>
 <YD+kP0z0yWm9UeDK@cmpxchg.org>
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On Wed, Mar 03, 2021 at 09:59:11AM -0500, Johannes Weiner wrote:
> On Wed, Mar 03, 2021 at 11:46:55AM +0800, Chengming Zhou wrote:
> > This patch series is RESEND of the previous patches on psi subsystem. A few
> > weeks passed since the last review, so I put them together and resend for
> > more convenient review and merge.
> > 
> > Patch 1 add PSI_CPU_FULL state means all non-idle tasks in a cgroup are delayed
> > on the CPU resource which used by others outside of the cgroup or throttled
> > by the cgroup cpu.max configuration.
> > 
> > Patch 2 use ONCPU state and the current in_memstall flag to detect reclaim,
> > remove the hook in timer tick to make code more concise and maintainable.
> > And patch 3 adds unlikely() annotations to move the pressure state branches
> > out of line to eliminate undesirable jumps during wakeup and sleeps.
> > 
> > Patch 4 optimize the voluntary sleep switch by remove one call of
> > psi_group_change() for every common cgroup ancestor of the two tasks.
> > 
> > Chengming Zhou (3):
> >   psi: Add PSI_CPU_FULL state
> >   psi: Use ONCPU state tracking machinery to detect reclaim
> >   psi: Optimize task switch inside shared cgroups
> > 
> > Johannes Weiner (1):
> >   psi: pressure states are unlikely
> 
> Peter, would you mind routing these through the sched tree for 5.13?

Yes, I can do that. Thanks!