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From: Frederic Weisbecker <frederic@kernel.org>
To: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Anna-Maria Behnsen <anna-maria@linutronix.de>,
	Vincent Guittot <vincent.guittot@linaro.org>,
	Peter Zijlstra <peterz@infradead.org>,
	linux-kernel@vger.kernel.org,
	Thomas Gleixner <tglx@linutronix.de>,
	"Gautham R. Shenoy" <gautham.shenoy@amd.com>,
	Ingo Molnar <mingo@redhat.com>,
	Juri Lelli <juri.lelli@redhat.com>,
	Dietmar Eggemann <dietmar.eggemann@arm.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	Ben Segall <bsegall@google.com>, Mel Gorman <mgorman@suse.de>,
	Daniel Bristot de Oliveira <bristot@redhat.com>,
	Valentin Schneider <vschneid@redhat.com>
Subject: Re: Stopping the tick on a fully loaded system
Date: Wed, 26 Jul 2023 12:59:08 +0200	[thread overview]
Message-ID: <ZMD8fP36By1KYgkk@localhost.localdomain> (raw)
In-Reply-To: <CAJZ5v0gJj_xGHcABCDoX2t8aR+9kXr7fvRFF+5KBO5MJz9kFWQ@mail.gmail.com>

Le Tue, Jul 25, 2023 at 04:27:56PM +0200, Rafael J. Wysocki a écrit :
> On Tue, Jul 25, 2023 at 3:07 PM Anna-Maria Behnsen
> I'll let Frederic respond to the above, but from my perspective it all
> just means that the idle governors in use today are not perfect.
> 
> However, they will never be perfect, because they only have a little
> time to make a decision, so it's a matter of balancing that with
> precision.

So, even without considering Anna-Maria's patchset, sparing
the next timer lookup if we already know we won't stop it would show
quite a benefit because that lookup involves locking and quite some
overhead walking through all levels.

Thanks.

  parent reply	other threads:[~2023-07-26 10:59 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-07-20  6:51 Stopping the tick on a fully loaded system Anna-Maria Behnsen
2023-07-20  7:38 ` Vincent Guittot
2023-07-20 13:00   ` Anna-Maria Behnsen
2023-07-20 13:55     ` Vincent Guittot
2023-07-23 21:21     ` Frederic Weisbecker
2023-07-24  8:23       ` Rafael J. Wysocki
2023-07-25 13:07         ` Anna-Maria Behnsen
2023-07-25 14:27           ` Rafael J. Wysocki
2023-07-25 22:28             ` Peter Zijlstra
2023-07-26 15:10               ` Rafael J. Wysocki
2023-07-26 15:53                 ` Rafael J. Wysocki
2023-07-26 16:14                   ` Peter Zijlstra
2023-07-26 16:49                     ` Peter Zijlstra
2023-07-26 21:26                       ` Peter Zijlstra
2023-07-27  7:59                     ` Peter Zijlstra
2023-07-27 20:10                       ` Rafael J. Wysocki
2023-07-26 16:40               ` Anna-Maria Behnsen
2023-07-26 18:30                 ` Rafael J. Wysocki
2023-07-26 20:09                   ` Peter Zijlstra
2023-07-26 10:59             ` Frederic Weisbecker [this message]
2023-07-26 15:07               ` Rafael J. Wysocki
2023-07-26 10:47           ` Frederic Weisbecker

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