From: Pierre Ossman <drzeus-list@drzeus.cx>
To: lsorense@csclub.uwaterloo.ca (Lennart Sorensen)
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>,
Adam Belay <abelay@novell.com>,
linux-pm@lists.linux-foundation.org,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [RFC][PATCH] cpuidle: avoid singing capacitors
Date: Sat, 1 Mar 2008 13:31:27 +0100 [thread overview]
Message-ID: <20080301133127.0a85f319@mjolnir.drzeus.cx> (raw)
In-Reply-To: <20080229214407.GC1289@csclub.uwaterloo.ca>
On Fri, 29 Feb 2008 16:44:07 -0500
lsorense@csclub.uwaterloo.ca (Lennart Sorensen) wrote:
> On Fri, Feb 29, 2008 at 07:38:12PM +0100, Pierre Ossman wrote:
> > +/*
> > + * The minimum number of ticks needed to not oscillate faster than
> > + * 500 Hz.
> > + */
> > +#define MIN_DEEP_INTERVAL (HZ / 500)
>
> What happens here if HZ < 500? Or does the fact that you have less than
> 500HZ jiffies automatically imply that you can't go to sleep more than
> the jiffy rate times per second?
A low HZ will still go to sleep very often (provided NO_HZ is in effect). But a HZ < 500 makes that number up there turn to zero. But the check further down makes sure that at least 1 tick passes. So that means it will not enter C3 more often than min(HZ, 500) Hz. Another reason to stop using jiffies.
--
-- Pierre Ossman
Linux kernel, MMC maintainer http://www.kernel.org
PulseAudio, core developer http://pulseaudio.org
rdesktop, core developer http://www.rdesktop.org
next prev parent reply other threads:[~2008-03-01 12:32 UTC|newest]
Thread overview: 70+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-02-29 18:38 [RFC][PATCH] cpuidle: avoid singing capacitors Pierre Ossman
2008-02-29 21:44 ` Lennart Sorensen
2008-03-01 12:31 ` Pierre Ossman [this message]
2008-03-01 13:40 ` Pierre Ossman
2008-03-02 2:27 ` Lee Revell
2008-03-02 14:17 ` Pierre Ossman
2008-03-03 12:36 ` Andi Kleen
2008-03-03 20:18 ` [PATCH] " Pierre Ossman
2008-03-03 20:46 ` Pavel Machek
2008-03-03 21:03 ` Pierre Ossman
2008-03-03 21:08 ` Pavel Machek
2008-03-03 21:14 ` Pallipadi, Venkatesh
2008-03-03 21:17 ` Pierre Ossman
2008-03-03 22:04 ` Pallipadi, Venkatesh
2008-03-03 23:05 ` [linux-pm] " Alan Stern
2008-03-03 23:10 ` Andi Kleen
2008-03-04 4:00 ` Dave Jones
2008-03-04 6:14 ` Pierre Ossman
2008-03-04 17:19 ` Pierre Ossman
2008-03-04 17:29 ` Andi Kleen
2008-03-04 17:30 ` Pierre Ossman
2008-03-04 17:43 ` Andi Kleen
2008-03-04 18:04 ` Pierre Ossman
2008-03-04 18:34 ` Andi Kleen
2008-03-05 6:04 ` Pierre Ossman
2008-03-05 15:48 ` Andi Kleen
2008-03-05 16:53 ` Pierre Ossman
2008-03-05 17:32 ` Andi Kleen
2008-03-04 19:01 ` Pallipadi, Venkatesh
2008-03-05 6:02 ` Pierre Ossman
2008-03-05 8:40 ` Pierre Ossman
2008-03-05 9:03 ` Pavel Machek
2008-03-05 13:42 ` Pierre Ossman
2008-03-05 13:47 ` Pavel Machek
2008-03-05 13:52 ` Pierre Ossman
2008-03-06 8:27 ` Pierre Ossman
2008-03-09 14:16 ` Pierre Ossman
2008-03-09 18:19 ` Rafael J. Wysocki
2008-03-09 18:50 ` Alan Stern
2008-03-09 19:30 ` Henrique de Moraes Holschuh
2008-03-09 20:14 ` Pierre Ossman
2008-03-09 20:41 ` Henrique de Moraes Holschuh
2008-03-09 20:54 ` Henrique de Moraes Holschuh
2008-03-10 10:00 ` Pavel Machek
2008-03-10 12:49 ` Pierre Ossman
2008-03-10 13:04 ` Andi Kleen
2008-03-10 13:29 ` Pierre Ossman
2008-03-12 19:11 ` Len Brown
2008-03-13 8:10 ` Pavel Machek
2008-03-13 10:42 ` Andi Kleen
2008-03-14 4:13 ` Len Brown
2008-03-13 16:34 ` Pierre Ossman
2008-03-13 16:47 ` Pallipadi, Venkatesh
2008-03-13 17:44 ` Pierre Ossman
2008-03-13 17:49 ` Pierre Ossman
2008-03-14 19:40 ` Pierre Ossman
2008-03-14 21:15 ` Pallipadi, Venkatesh
2008-03-15 0:41 ` Pierre Ossman
2008-03-11 7:51 ` Pierre Ossman
2008-03-11 10:48 ` Andi Kleen
2008-03-11 15:20 ` Pierre Ossman
2008-03-11 17:31 ` Pierre Ossman
2008-03-12 19:17 ` Len Brown
2008-03-12 20:31 ` Len Brown
2008-03-04 9:40 ` Andi Kleen
2008-03-03 23:09 ` Andi Kleen
[not found] <a2itf-5jB-27@gated-at.bofh.it>
2008-02-29 21:09 ` [RFC][PATCH] " Alan Jenkins
2008-03-01 12:29 ` Pierre Ossman
2008-03-05 17:32 ` Jeremy Fitzhardinge
2008-03-05 18:01 ` Pierre Ossman
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