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From: Ingo Molnar <mingo@elte.hu>
To: "Zhang, Yanmin" <yanmin.zhang@intel.com>
Cc: a.p.zijlstra@chello.nl,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: scale sysctl_sched_shares_ratelimit with nr_cpus
Date: Mon, 18 Aug 2008 09:01:47 +0200	[thread overview]
Message-ID: <20080818070147.GA4801@elte.hu> (raw)
In-Reply-To: <37E52D09333DE2469A03574C88DBF40F024EBD69@pdsmsx414.ccr.corp.intel.com>


* Zhang, Yanmin <yanmin.zhang@intel.com> wrote:

> >>cool. It's already upstream (post-rc3 commit):
> [YM] But comparing with 2.6.26, volanoMark result still has about 60%
> regression.

Does a scheduler trace show anything about why that drop happens? Do 
something like this to trace the scheduler:

assuming debugfs is mounted under /debug and CONFIG_SCHED_TRACER=y:

  echo 1 > /debug/tracing/tracing_cpumask
  echo sched_switch > /debug/tracing/available_tracers
  cat /debug/tracing/trace_pipe > trace.txt

( regarding tracing_cpumask: trace only 1 CPU to make sure volanomark is 
  not disturbed too much by many-CPUs tracing. )

	Ingo

  reply	other threads:[~2008-08-18  7:02 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <37E52D09333DE2469A03574C88DBF40F024EBD2F@pdsmsx414.ccr.corp.intel.com>
2008-08-18  6:52 ` scale sysctl_sched_shares_ratelimit with nr_cpus Ingo Molnar
2008-08-18  6:54   ` Zhang, Yanmin
2008-08-18  7:01     ` Ingo Molnar [this message]
2008-08-18  8:26       ` Zhang, Yanmin
2008-08-18  8:42         ` Ingo Molnar
2008-08-18  8:45           ` Zhang, Yanmin

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