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Date:   Thu, 5 Jul 2018 12:46:32 +0200
From:   Peter Zijlstra <peterz@infradead.org>
To:     Xunlei Pang <xlpang@linux.alibaba.com>
Cc:     Ingo Molnar <mingo@redhat.com>,
        Frederic Weisbecker <frederic@kernel.org>,
        Tejun Heo <tj@kernel.org>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] sched/cputime: Ensure correct utime and stime proportion
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On Wed, Jun 27, 2018 at 08:22:42PM +0800, Xunlei Pang wrote:
> tick-based whole utime is utime_0, tick-based whole stime
> is stime_0, scheduler time is rtime_0. 

> For a long time, the process runs mainly in userspace with
> run-sleep patterns, and because two different clocks, it
> is possible to have the following condition:
>   rtime_0 < utime_0 (as with little stime_0)

I don't follow... what?

Why are you, and why do you think it makes sense to, compare rtime_0
against utime_0 ?

The [us]time_0 are, per your earlier definition, ticks. They're not an
actual measure of time. Do not compare the two, that makes no bloody
sense.