From: Andi Kleen <ak@suse.de>
To: Joe Korty <joe.korty@ccur.com>
Cc: Christoph Lameter <christoph@lameter.com>,
Linus Torvalds <torvalds@osdl.org>,
randy_dunlap <rdunlap@xenotime.net>,
akpm@osdl.org, linux-kernel@vger.kernel.org, shai@scalex86.org,
ak@suse.de
Subject: Re: [PATCH] i386: Selectable Frequency of the Timer Interrupt.
Date: Tue, 17 May 2005 15:58:34 +0200 [thread overview]
Message-ID: <20050517135834.GG9699@wotan.suse.de> (raw)
In-Reply-To: <20050517134434.GA26822@tsunami.ccur.com>
> > + help
> > + 100 HZ is a typical choice for servers, SMP and NUMA systems
> > + with lots of processors that may show reduced performance if
> > + too many timer interrupts are occurring.
>
> One of the options should mention the power savings benefit on laptops.
> How about:
Actually it is not 100% clear. The ACPI idle code relies on
the timer right now to go from C1 to C2/C3. It basically
goes down in a staircase, first staying in C1, then when woken
up and still idle go down lower etc.
With HZ=100 the minimal latency (assuming no other interrupts) to go from C1
to C2 is 10ms, not 1ms, which might be even a power loss in some workloads.
-Andi
P.S.: The SUSE 2.4 kernels had for some time variable HZ, settable at boot.
It surprisingly didn't cause too much slowdown or code bloat and only
needed minor fixes over the tree. Might be worth considering at least
as a CONFIG
next prev parent reply other threads:[~2005-05-17 13:58 UTC|newest]
Thread overview: 225+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-05-16 19:45 [PATCH] i386: Selectable Frequency of the Timer Interrupt christoph
2005-05-16 20:51 ` Lee Revell
2005-05-17 0:55 ` christoph
2005-05-17 23:25 ` Lee Revell
2005-05-17 23:48 ` Nish Aravamudan
2005-05-18 0:03 ` Valdis.Kletnieks
2005-05-18 0:08 ` Lee Revell
2005-05-16 22:09 ` Andrew Morton
2005-05-17 2:38 ` Christoph Lameter
2005-05-17 2:46 ` randy_dunlap
2005-05-17 2:55 ` Christoph Lameter
2005-05-17 3:01 ` randy_dunlap
2005-05-17 3:37 ` Linus Torvalds
2005-05-17 3:40 ` Andi Kleen
2005-05-17 10:51 ` Paulo Marques
2005-05-17 13:19 ` Andi Kleen
2005-05-17 5:31 ` Christoph Lameter
2005-05-17 13:44 ` Joe Korty
2005-05-17 13:58 ` Andi Kleen [this message]
2005-05-17 15:43 ` Christoph Lameter
2005-05-18 18:50 ` Pavel Machek
2005-05-18 19:03 ` Lee Revell
2005-05-18 20:41 ` Tony Lindgren
2005-05-18 19:25 ` Linus Torvalds
2005-05-18 20:46 ` Tony Lindgren
2005-05-17 3:01 ` Coywolf Qi Hunt
[not found] <200506231828.j5NISlCe020350@hera.kernel.org>
2005-07-08 21:49 ` Chris Wedgwood
2005-07-08 21:59 ` Andrew Morton
2005-07-08 22:05 ` Chris Wedgwood
2005-07-08 22:08 ` Linus Torvalds
2005-07-10 10:45 ` Denis Vlasenko
2005-07-08 22:22 ` Lee Revell
2005-07-08 22:33 ` Andrew Morton
2005-07-08 22:59 ` Martin J. Bligh
2005-07-08 23:03 ` Chris Wedgwood
2005-07-08 23:14 ` Martin J. Bligh
2005-07-08 23:29 ` David S. Miller
2005-07-08 23:40 ` Lee Revell
2005-07-09 17:08 ` Martin Schlemmer
2005-07-09 18:16 ` Lee Revell
2005-07-09 18:31 ` Arjan van de Ven
2005-07-09 18:33 ` Chris Wedgwood
2005-07-09 18:36 ` Lee Revell
2005-07-09 19:12 ` Andrew Morton
2005-07-09 19:16 ` Lee Revell
2005-07-09 20:30 ` randy_dunlap
2005-07-09 21:25 ` Lee Revell
2005-07-09 23:30 ` Randy Dunlap
2005-07-11 18:35 ` Martin J. Bligh
2005-07-11 13:23 ` Alan Cox
2005-07-11 14:05 ` Theodore Ts'o
2005-07-11 14:08 ` Arjan van de Ven
2005-07-11 15:18 ` Alan Cox
2005-07-12 2:13 ` Eric St-Laurent
2005-07-11 16:02 ` Chris Wedgwood
2005-07-15 12:17 ` Pavel Machek
2005-07-13 15:59 ` Bill Davidsen
2005-07-13 16:47 ` Lee Revell
2005-07-10 0:44 ` pmarques
2005-07-09 18:39 ` Diego Calleja
2005-07-09 18:41 ` Lee Revell
2005-07-09 18:49 ` Lee Revell
2005-07-09 18:50 ` Chris Wedgwood
2005-07-11 18:38 ` Martin J. Bligh
2005-07-11 20:25 ` Lee Revell
2005-07-11 20:39 ` Chris Friesen
2005-07-12 0:30 ` Lee Revell
2005-07-12 4:07 ` Martin J. Bligh
2005-07-12 4:13 ` Lee Revell
2005-07-12 4:30 ` Martin J. Bligh
2005-07-12 14:21 ` Lee Revell
2005-07-12 14:24 ` Lee Revell
2005-07-12 14:56 ` Martin J. Bligh
2005-07-12 15:00 ` Lee Revell
2005-07-12 15:08 ` Martin J. Bligh
2005-07-12 15:10 ` Lee Revell
2005-07-12 15:22 ` Martin J. Bligh
2005-07-12 19:30 ` Lee Revell
2005-07-12 20:58 ` Lee Revell
2005-07-12 22:22 ` Martin J. Bligh
2005-07-13 5:37 ` Lee Revell
2005-07-13 10:38 ` Jan Engelhardt
2005-07-12 0:38 ` George Anzinger
2005-07-12 12:10 ` Vojtech Pavlik
2005-07-12 12:39 ` Con Kolivas
2005-07-12 12:52 ` Con Kolivas
2005-07-12 15:57 ` George Anzinger
2005-07-12 16:27 ` Vojtech Pavlik
2005-07-13 16:26 ` Bill Davidsen
2005-07-13 16:46 ` Lee Revell
2005-07-13 17:24 ` David Lang
2005-07-13 18:42 ` Vojtech Pavlik
2005-07-13 19:10 ` Linus Torvalds
2005-07-13 19:13 ` Lee Revell
2005-07-13 19:32 ` Dmitry Torokhov
2005-07-13 19:33 ` Martin J. Bligh
2005-07-13 20:02 ` Fernando Lopez-Lezcano
2005-07-13 20:17 ` Lee Revell
2005-07-13 20:24 ` Lee Revell
2005-07-13 20:48 ` Andrew Morton
2005-07-13 21:16 ` Chris Wedgwood
2005-07-13 21:24 ` Lee Revell
2005-07-13 21:35 ` Martin J. Bligh
2005-07-13 21:37 ` Chris Friesen
2005-07-13 21:56 ` Chris Wedgwood
2005-07-13 23:07 ` George Anzinger
2005-07-13 21:29 ` Martin J. Bligh
2005-07-13 21:30 ` Lee Revell
2005-07-13 23:41 ` dean gaudet
2005-07-14 0:07 ` Petr Vandrovec
2005-07-14 9:24 ` Jan Engelhardt
2005-07-14 14:20 ` Lee Revell
2005-07-14 18:05 ` Jan Engelhardt
2005-07-14 18:20 ` Linus Torvalds
2005-07-14 0:51 ` Chris Wedgwood
2005-07-14 1:13 ` dean gaudet
2005-07-14 1:33 ` Lee Revell
2005-07-14 1:54 ` Linus Torvalds
2005-07-14 7:42 ` Arjan van de Ven
2005-07-14 12:13 ` Vojtech Pavlik
2005-07-14 16:37 ` Linus Torvalds
2005-07-14 17:02 ` Arjan van de Ven
2005-07-14 17:21 ` Linus Torvalds
2005-07-14 19:09 ` Russell King
2005-07-14 20:06 ` Linus Torvalds
2005-07-14 20:30 ` Russell King
2005-07-15 8:15 ` Gerd Knorr
2005-07-14 20:38 ` Johannes Stezenbach
2005-07-14 17:42 ` Al Boldi
2005-07-14 19:42 ` john stultz
2005-07-14 20:13 ` Linus Torvalds
2005-07-14 20:41 ` Christoph Lameter
2005-07-14 23:03 ` Chris Wedgwood
2005-07-14 21:54 ` john stultz
2005-07-14 22:43 ` Alan Cox
2005-07-14 23:19 ` Linus Torvalds
2005-07-15 12:33 ` Alan Cox
2005-07-14 17:10 ` Chris Friesen
2005-07-14 17:24 ` Linus Torvalds
2005-07-14 19:18 ` john stultz
2005-07-14 22:37 ` Alan Cox
2005-07-14 23:13 ` Linus Torvalds
2005-07-14 23:32 ` Linus Torvalds
2005-07-15 1:17 ` Eric St-Laurent
2005-07-14 23:17 ` Lee Revell
2005-07-14 23:25 ` Linus Torvalds
2005-07-14 23:41 ` Lee Revell
2005-07-14 23:49 ` Linus Torvalds
2005-07-14 23:53 ` Lee Revell
2005-07-15 12:42 ` Bill Davidsen
2005-07-14 23:57 ` Lee Revell
2005-07-15 2:30 ` Fernando Lopez-Lezcano
2005-07-15 12:46 ` Bill Davidsen
2005-07-15 16:46 ` Fernando Lopez-Lezcano
2005-07-14 23:50 ` Lee Revell
2005-07-15 4:08 ` Con Kolivas
2005-07-15 4:17 ` Lee Revell
2005-07-15 4:54 ` Zwane Mwaikambo
2005-07-15 16:59 ` Lee Revell
2005-07-15 14:51 ` kernel
2005-07-14 18:00 ` Andrew Morton
2005-07-14 8:38 ` Ingo Molnar
2005-07-14 14:55 ` Lee Revell
2005-07-14 15:02 ` Christoph Lameter
2005-07-14 15:25 ` Lee Revell
2005-07-14 2:08 ` Lee Revell
2005-07-14 9:56 ` Maciej W. Rozycki
2005-07-15 0:04 ` Jesper Juhl
2005-07-15 0:15 ` Lee Revell
2005-07-15 0:17 ` Jesper Juhl
2005-07-15 0:42 ` Linus Torvalds
2005-07-15 8:41 ` Russell King
2005-07-15 0:24 ` Linus Torvalds
2005-07-15 1:40 ` Jesper Juhl
2005-07-15 2:00 ` Eric St-Laurent
2005-07-15 19:58 ` Stephen Pollei
2005-07-16 5:16 ` Eric St-Laurent
2005-07-15 2:07 ` Bill Davidsen
2005-07-15 9:36 ` Matthias Urlichs
2005-07-15 3:46 ` Jesper Juhl
2005-07-15 5:04 ` Linus Torvalds
2005-07-15 13:12 ` Jesper Juhl
2005-07-17 2:13 ` Jesper Juhl
2005-07-17 2:35 ` Lee Revell
2005-07-17 2:35 ` Nish Aravamudan
2005-07-17 3:55 ` Lee Revell
2005-07-23 23:40 ` randy_dunlap
2005-07-25 13:26 ` Vojtech Pavlik
2005-07-23 23:48 ` randy_dunlap
2005-07-23 23:52 ` Jesper Juhl
2005-07-24 12:58 ` Bill Davidsen
2005-07-15 8:44 ` Russell King
2005-07-15 15:41 ` Pavel Machek
2005-07-13 20:02 ` Diego Calleja
2005-07-13 19:35 ` Benjamin LaHaise
2005-07-13 19:41 ` Vojtech Pavlik
2005-07-13 19:53 ` Benjamin LaHaise
2005-07-14 10:04 ` Maciej W. Rozycki
2005-07-13 19:52 ` George Anzinger
2005-07-13 23:54 ` Con Kolivas
2005-07-14 0:43 ` George Anzinger
2005-07-14 10:25 ` Krzysztof Halasa
2005-07-14 12:19 ` Vojtech Pavlik
2005-07-14 21:19 ` Krzysztof Halasa
2005-07-15 1:19 ` Bill Davidsen
2005-07-12 13:30 ` Vojtech Pavlik
2005-07-12 15:26 ` Martin J. Bligh
2005-07-12 17:50 ` john stultz
2005-07-12 22:30 ` Nishanth Aravamudan
2005-07-12 17:56 ` john stultz
2005-07-12 0:45 ` Lee Revell
2005-07-11 13:18 ` Alan Cox
2005-07-14 21:35 Brown, Len
2005-07-15 9:37 ` Maciej W. Rozycki
2005-07-15 16:33 Brown, Len
2005-07-15 16:54 ` Chris Wedgwood
[not found] <F7DC2337C7631D4386A2DF6E8FB22B300410F46A@hdsmsx401.amr.corp.intel.com.suse.lists.linux.kernel>
2005-07-15 17:02 ` Andi Kleen
2005-07-15 17:23 ` Venkatesh Pallipadi
2005-07-15 17:54 ` Maciej W. Rozycki
2005-07-15 17:58 ` Andi Kleen
2005-07-18 10:47 ` Maciej W. Rozycki
2005-07-15 18:01 ` Venkatesh Pallipadi
2005-07-18 11:17 ` Maciej W. Rozycki
2005-07-15 17:57 ` Andi Kleen
2005-07-15 18:09 ` Venkatesh Pallipadi
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