From: Chris Snook <csnook@redhat.com>
To: Chris Friesen <cfriesen@nortel.com>
Cc: Ingo Molnar <mingo@elte.hu>, Tong Li <tong.n.li@intel.com>,
linux-kernel@vger.kernel.org
Subject: Re: [RFC] scheduler: improve SMP fairness in CFS
Date: Wed, 25 Jul 2007 16:55:05 -0400 [thread overview]
Message-ID: <46A7B8A9.4040400@redhat.com> (raw)
In-Reply-To: <46A7B4DE.4030301@nortel.com>
Chris Friesen wrote:
> Ingo Molnar wrote:
>
>> the 3s is the problem: change that to 60s! We no way want to
>> over-migrate for SMP fairness, the change i did gives us reasonable
>> long-term SMP fairness without the need for high-rate rebalancing.
>
> Actually, I do have requirements from our engineering guys for
> short-term fairness. They'd actually like decent fairness over even
> shorter intervals...1 second would be nice, 2 is acceptable.
>
> They are willing to trade off random peak performance for predictability.
>
> Chris
>
The sysctls for CFS have nanosecond resolution. They default to
millisecond-order values, but you can set them much lower. See sched_fair.c for
the knobs and their explanations.
-- Chris
next prev parent reply other threads:[~2007-07-25 20:55 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-07-23 18:38 [RFC] scheduler: improve SMP fairness in CFS Tong Li
2007-07-23 20:00 ` Andi Kleen
2007-07-23 21:10 ` Li, Tong N
2007-07-23 21:25 ` Chris Friesen
2007-07-24 9:43 ` Andi Kleen
2007-07-23 23:40 ` Chris Snook
2007-07-24 8:07 ` Chris Snook
2007-07-24 17:11 ` Li, Tong N
2007-07-24 17:07 ` Tong Li
2007-07-24 18:08 ` Chris Snook
2007-07-24 19:47 ` Chris Friesen
2007-07-24 20:39 ` Chris Snook
2007-07-24 20:58 ` Li, Tong N
2007-07-24 21:09 ` Chris Snook
2007-07-24 21:23 ` Chris Friesen
2007-07-24 21:45 ` Chris Snook
2007-07-24 23:33 ` Chris Friesen
2007-07-24 21:06 ` Bill Huey
2007-07-24 21:22 ` Chris Snook
2007-07-24 23:14 ` Bill Huey
2007-07-24 21:12 ` Chris Friesen
2007-07-25 11:01 ` Ingo Molnar
2007-07-25 12:03 ` Ingo Molnar
2007-07-25 17:23 ` Tong Li
2007-07-25 19:24 ` Ingo Molnar
2007-07-25 20:38 ` Chris Friesen
2007-07-25 20:55 ` Chris Snook [this message]
2007-07-25 21:15 ` Li, Tong N
2007-07-25 22:24 ` Chris Snook
2007-07-26 19:00 ` Tong Li
2007-07-26 21:31 ` Ingo Molnar
2007-07-26 22:00 ` Li, Tong N
2007-07-27 1:34 ` Tong Li
2007-07-27 17:16 ` Chris Snook
2007-07-27 19:03 ` Tong Li
2007-07-27 22:20 ` Bill Huey
2007-07-27 23:36 ` Chris Snook
2007-07-28 0:54 ` Bill Huey
2007-07-28 2:59 ` Chris Snook
2007-07-28 19:38 ` Tong Li
2007-07-29 2:40 ` Chris Snook
2007-07-28 19:23 ` Tong Li
2007-07-29 3:01 ` Chris Snook
2007-07-25 18:20 ` Li, Tong N
2007-07-25 19:18 ` Ingo Molnar
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