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Sender: Ingo Molnar <mingo.kernel.org@gmail.com>
Date:   Mon, 9 Oct 2023 12:49:44 +0200
From:   Ingo Molnar <mingo@kernel.org>
To:     yang.yang29@zte.com.cn
Cc:     surenb@google.com, peterz@infradead.org, hannes@cmpxchg.org,
        mingo@redhat.com, linux-kernel@vger.kernel.org,
        juri.lelli@redhat.com
Subject: Re: [PATCH linux-next v2] sched/psi: Avoid update triggers and
 rtpoll_total when it is unnecessary
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 <202310071421311735972@zte.com.cn>
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* yang.yang29@zte.com.cn <yang.yang29@zte.com.cn> wrote:

> From: Yang Yang <yang.yang29@zte.com.cn>
> 
> When psimon wakes up and there are no state changes for rtpoll_states,
> it's unnecessary to update triggers and rtpoll_total because the pressures
> being monitored by user have not changed. This will help to slightly reduce
> unnecessary computations of psi.
> 
> There are also some minor related optimizations, please see below.
> 
> The parameter update_total in update_triggers() is useless now. Since if
> changed_states & group->rtpoll_states is true, new_stall in update_triggers()
> will be true, then update_total should also be true. We have no need for
> update_total to help judgment whether to update rtpoll_total, so delete
> update_total.
> 
> Update_triggers() always return now + group->rtpoll_min_period, and the
> return value is only used by psi_rtpoll_work(), so change update_triggers()
> to a void function, let group->rtpoll_next_update = now +
> group->rtpoll_min_period directly.

Yeah, so please split this up into 3 patches: one change per patch, even
if each patch is relatively small.

Thanks,

	Ingo