From: Ingo Molnar <mingo@elte.hu>
To: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>,
Thomas Gleixner <tglx@linutronix.de>,
linux kernel mailing list <linux-kernel@vger.kernel.org>
Subject: Re: delayacct regression in 2.6.24 git
Date: Fri, 2 Nov 2007 16:25:29 +0100 [thread overview]
Message-ID: <20071102152529.GB20134@elte.hu> (raw)
In-Reply-To: <472B2908.7020507@linux.vnet.ibm.com>
* Balbir Singh <balbir@linux.vnet.ibm.com> wrote:
> Hi, Ingo,
>
> I missed commit 75d4ef16a6aa84f708188bada182315f80aab6fa
> "sched: fix delay accounting performance regression"
>
> Without these changes, I find that delay accounting does
> not work as expected, I see zeros in the field for virtual,delay
> and count(s).
>
> CPU count real total virtual total delay total
> 0 535861848 0 0
>
>
> This breaks existing delay accounting behaviour.
>
> Am I missing something?
delay accounting was causing context-switch slowdown because it called
sched_clock() explicitly - but indeed my fix to that is wrong ...
how about reverting the change but also using rq->clock instead of
sched_clock()?
Ingo
next prev parent reply other threads:[~2007-11-02 15:25 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-11-02 13:41 Balbir Singh
2007-11-02 15:25 ` Ingo Molnar [this message]
2007-11-02 16:28 ` Balbir Singh
2007-11-03 8:31 ` Ingo Molnar
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