From: Frederic Weisbecker <frederic@kernel.org>
To: Stian Halseth <stian@itx.no>
Cc: Thomas Gleixner <tglx@kernel.org>,
Anna-Maria Behnsen <anna-maria@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Shrikanth Hegde <sshegde@linux.ibm.com>,
regressions@lists.linux.dev, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3] sched/cputime: Don't account idle time twice after dyntick-idle
Date: Wed, 14 Oct 2026 14:17:46 +0200 [thread overview]
Message-ID: <as9y6gQSpDPq3z9A@localhost.localdomain> (raw)
In-Reply-To: <20261007142950.547604-1-stian@itx.no>
Le Wed, Oct 07, 2026 at 04:29:50PM +0200, Stian Halseth a écrit :
> On idle exit the dyntick-idle accounting accounts the time up to now,
> then the tick is restarted on its old period. The first tick accounts a
> whole TICK_NSEC to whatever runs, although the part of that period
> before the idle exit has just been accounted as idle time, or with
> IRQ_TIME_ACCOUNTING as IRQ time. That is up to a full tick per idle
> exit, and /proc/stat reports more idle time than wall time.
>
> Record how much of the current tick period dyntick-idle has accounted,
> and leave it out of the tick that ends the period.
>
> Fixes: cf6444c3e1bb7 ("tick/sched: Unify idle cputime accounting")
> Link: https://lore.kernel.org/all/20261004142724.3896396-1-stian@itx.no/
> Signed-off-by: Stian Halseth <stian@itx.no>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Thank you very much!
--
Frederic Weisbecker
SUSE Labs
prev parent reply other threads:[~2026-10-14 12:17 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-07 14:29 [PATCH v3] sched/cputime: Don't account idle time twice after dyntick-idle Stian Halseth
2026-10-14 12:17 ` Frederic Weisbecker [this message]
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