From: "Li, Tong N" <tong.n.li@intel.com>
To: Andi Kleen <andi@firstfloor.org>
Cc: mingo@elte.hu, linux-kernel@vger.kernel.org
Subject: Re: [RFC] scheduler: improve SMP fairness in CFS
Date: Mon, 23 Jul 2007 14:10:15 -0700 [thread overview]
Message-ID: <1185225015.3593.15.camel@tongli.jf.intel.com> (raw)
In-Reply-To: <p73ir8aubzx.fsf@bingen.suse.de>
I benchmarked an early version of this code (against 2.6.21) with
SPECjbb, SPEComp, kernbench, etc. on an 8-processor system, and didn't
see any slowdown compared to the stock scheduler. I'll generate the data
again with this version of the code. On the other hand, if locking does
become a problem for certain systems/workloads, increasing
sysctl_base_round_slice can reduce the locking frequency and alleviate
the problem, at the cost of being relatively less fair across the CPUs.
tong
On Mon, 2007-07-23 at 22:00 +0200, Andi Kleen wrote:
> Tong Li <tong.n.li@intel.com> writes:
> > +
> > + read_lock_irqsave(&dwrr_highest_lock, flags);
>
> That lock looks like it would bounce between CPUs like crazy.
> Did you try any benchmarks on a larger system?
>
> -Andi
next prev parent reply other threads:[~2007-07-23 21:10 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-07-23 18:38 Tong Li
2007-07-23 20:00 ` Andi Kleen
2007-07-23 21:10 ` Li, Tong N [this message]
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
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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