linux-kernel - Re: [RESEND PATCH 0/2] iowait and idle fixes in /proc/stat

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Message-ID: <11c8b2ee-7d87-ae0b-c11b-71a052865000@oracle.com>
Date:   Mon, 14 Sep 2020 10:31:51 -0600
From:   Tom Hromatka <tom.hromatka@...cle.com>
To:     linux-kernel@...r.kernel.org, linux-fsdevel@...r.kernel.org,
        fweisbec@...il.com, tglx@...utronix.de, mingo@...nel.org,
        adobriyan@...il.com
Subject: Re: [RESEND PATCH 0/2] iowait and idle fixes in /proc/stat

Thanks for your time and  feedback, Thomas and Alexey.  I'll
address the comments and send out a v2 in the next couple
days.

Thanks!

Tom


On 9/9/20 8:41 AM, Tom Hromatka wrote:
> A customer is using /proc/stat to track cpu usage in a VM and noted
> that the iowait and idle times behave strangely when a cpu goes
> offline and comes back online.
>
> This patchset addresses two issues that can cause iowait and idle
> to fluctuate up and down.  With these changes, cpu iowait and idle
> now only monotonically increase.
>
> Tom Hromatka (2):
>    tick-sched: Do not clear the iowait and idle times
>    /proc/stat: Simplify iowait and idle calculations when cpu is offline
>
>   fs/proc/stat.c           | 24 ++++++------------------
>   kernel/time/tick-sched.c |  9 +++++++++
>   2 files changed, 15 insertions(+), 18 deletions(-)
>