From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Christoph Lameter <cl@linux.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
Alok Kataria <akataria@vmware.com>,
"H. Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@elte.hu>,
Thomas Gleixner <tglx@linutronix.de>,
the arch/x86 maintainers <x86@kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
"alan@lxorguk.ukuu.org.uk" <alan@lxorguk.ukuu.org.uk>
Subject: Re: [PATCH] x86: Reduce the default HZ value
Date: Thu, 7 May 2009 10:54:41 -0700 [thread overview]
Message-ID: <20090507175441.GD6693@linux.vnet.ibm.com> (raw)
In-Reply-To: <alpine.DEB.1.10.0905071320010.22107@qirst.com>
On Thu, May 07, 2009 at 01:20:29PM -0400, Christoph Lameter wrote:
> On Thu, 7 May 2009, Peter Zijlstra wrote:
>
> > Another user is RCU, the grace period is tick driven, growing these
> > ticks by a factor 50 or so might require some tinkering with forced
> > grace periods when we notice our batch queues getting too long.
>
> One could also schedule RCU via hrtimers with a large fuzz period?
You could, but then you would still have a periodic interrupt introducing
jitter into your HPC workload. The approach I suggested allows RCU to be
happy with no periodic interrupts on any CPU that has only one runnable
task that is a CPU-bound user-level task (in addition to the idle task,
of course).
Thanx, Paul
next prev parent reply other threads:[~2009-05-07 17:54 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-05-04 18:44 [PATCH] x86: Reduce the default HZ value Alok Kataria
2009-05-05 21:21 ` H. Peter Anvin
2009-05-05 21:44 ` Alan Cox
2009-05-05 22:09 ` Alok Kataria
2009-05-05 22:33 ` Alan Cox
2009-05-05 23:37 ` Alok Kataria
2009-05-07 14:09 ` Christoph Lameter
2009-05-07 15:12 ` Alan Cox
2009-05-05 21:57 ` Alok Kataria
2009-05-07 14:13 ` Christoph Lameter
2009-05-07 15:14 ` Alan Cox
2009-05-07 15:20 ` Christoph Lameter
2009-05-07 15:30 ` H. Peter Anvin
2009-05-07 15:40 ` Christoph Lameter
2009-05-07 16:55 ` Jeff Garzik
2009-05-07 17:09 ` Alan Cox
2009-05-07 17:55 ` Jeff Garzik
2009-05-07 19:51 ` Alan Cox
2009-05-07 20:03 ` Jeff Garzik
2009-05-07 20:30 ` Alan Cox
2009-05-07 16:37 ` Alok Kataria
2009-05-07 17:07 ` Peter Zijlstra
2009-05-07 17:13 ` Peter Zijlstra
2009-05-07 17:18 ` Peter Zijlstra
2009-05-07 17:20 ` Christoph Lameter
2009-05-07 17:39 ` Peter Zijlstra
2009-05-07 17:40 ` Christoph Lameter
2009-05-07 17:54 ` Paul E. McKenney [this message]
2009-05-07 17:51 ` Christoph Lameter
2009-05-07 19:51 ` Paul E. McKenney
2009-05-07 17:36 ` Paul E. McKenney
2009-05-07 17:38 ` Peter Zijlstra
2009-05-07 18:01 ` Paul E. McKenney
2009-05-07 18:12 ` Christoph Lameter
2009-05-07 19:06 ` Paul E. McKenney
2009-05-07 19:53 ` Alan Cox
2009-05-07 19:56 ` Christoph Lameter
2009-05-07 20:24 ` Alan Cox
2009-05-07 20:21 ` Christoph Lameter
2009-05-08 10:32 ` Peter Zijlstra
2009-05-08 12:50 ` Paul E. McKenney
2009-05-08 14:16 ` Christoph Lameter
2009-05-08 15:06 ` Paul E. McKenney
2009-05-07 17:18 ` Christoph Lameter
2009-05-07 17:37 ` Peter Zijlstra
2009-05-07 17:34 ` Christoph Lameter
2009-05-07 17:55 ` Peter Zijlstra
2009-05-07 17:55 ` Christoph Lameter
2009-05-07 17:19 ` Christoph Lameter
2009-05-07 17:45 ` Peter Zijlstra
2009-05-07 17:50 ` Christoph Lameter
2009-05-07 19:17 ` Peter Zijlstra
2009-05-07 19:38 ` Christoph Lameter
2009-05-07 21:01 ` H. Peter Anvin
2009-05-07 16:35 ` Chris Snook
2009-05-07 16:56 ` Alok Kataria
2009-05-07 20:29 ` Chris Snook
2009-05-07 20:34 ` Alan Cox
2009-05-07 22:16 ` Ravikiran G Thirumalai
2009-05-07 22:19 ` Alok Kataria
2009-05-08 9:31 ` Alan Cox
-- strict thread matches above, loose matches on Subject: below --
2009-05-12 19:45 devzero
2009-05-13 23:30 ` Alok Kataria
2009-05-14 20:25 devzero
2009-05-14 20:29 ` Alan Cox
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20090507175441.GD6693@linux.vnet.ibm.com \
--to=paulmck@linux.vnet.ibm.com \
--cc=akataria@vmware.com \
--cc=alan@lxorguk.ukuu.org.uk \
--cc=cl@linux.com \
--cc=hpa@zytor.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=peterz@infradead.org \
--cc=tglx@linutronix.de \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.