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Date:   Thu, 25 Aug 2022 13:17:35 -0400
From:   Johannes Weiner <hannes@cmpxchg.org>
To:     Chengming Zhou <zhouchengming@bytedance.com>
Cc:     tj@kernel.org, mkoutny@suse.com, surenb@google.com,
        mingo@redhat.com, peterz@infradead.org, gregkh@linuxfoundation.org,
        corbet@lwn.net, cgroups@vger.kernel.org, linux-doc@vger.kernel.org,
        linux-kernel@vger.kernel.org, songmuchun@bytedance.com
Subject: Re: [PATCH v4 07/10] sched/psi: add PSI_IRQ to track IRQ/SOFTIRQ
 pressure
Message-ID: <Yweur4ugxvLbP2L2@cmpxchg.org>
References: <20220825164111.29534-1-zhouchengming@bytedance.com>
 <20220825164111.29534-8-zhouchengming@bytedance.com>
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On Fri, Aug 26, 2022 at 12:41:08AM +0800, Chengming Zhou wrote:
> Now PSI already tracked workload pressure stall information for
> CPU, memory and IO. Apart from these, IRQ/SOFTIRQ could have
> obvious impact on some workload productivity, such as web service
> workload.
> 
> When CONFIG_IRQ_TIME_ACCOUNTING, we can get IRQ/SOFTIRQ delta time
> from update_rq_clock_task(), in which we can record that delta
> to CPU curr task's cgroups as PSI_IRQ_FULL status.
> 
> Note we don't use PSI_IRQ_SOME since IRQ/SOFTIRQ always happen in
> the current task on the CPU, make nothing productive could run
> even if it were runnable, so we only use PSI_IRQ_FULL.
> 
> Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>

Acked-by: Johannes Weiner <hannes@cmpxchg.org>