From: Arjan van de Ven <arjan@linux.intel.com>
To: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Ingo Molnar <mingo@elte.hu>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: LatencyTOP infrastructure patch
Date: Mon, 21 Jan 2008 08:16:20 -0800 [thread overview]
Message-ID: <4794C554.4000200@linux.intel.com> (raw)
In-Reply-To: <20080121170415.125B.KOSAKI.MOTOHIRO@jp.fujitsu.com>
KOSAKI Motohiro wrote:
> Hi
>
>> +static void __sched
>> +account_global_scheduler_latency(struct task_struct *tsk, int usecs)
>> +{
>> + int i;
>> + int firstnonnull = MAXLR + 1;
>> +
>> + if (!tsk->latency_reason.reason)
>> + return;
>> +
>> + /* skip kernel threads for now */
>> + if (!tsk->mm)
>> + return;
>
> Why do you ignore kernel thread?
>
> may be, some network filesystem use kernel thread for local I/O.
> What do you think it?
kernel threads (by themselves) don't tend to result in user visible latency...
at least that's my assumption so far... if you think I'm wrong... I'm open to be shown
that we should count them.
next prev parent reply other threads:[~2008-01-21 16:18 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-01-18 17:36 [Announce] Development release 0.1 of the LatencyTOP tool Arjan van de Ven
2008-01-18 17:39 ` [patch 1/3] LatencyTOP infrastructure patch Arjan van de Ven
2008-01-20 11:34 ` Helge Deller
2008-01-20 16:47 ` Dmitry Adamushko
2008-01-20 17:18 ` Dmitry Adamushko
2008-01-21 8:06 ` KOSAKI Motohiro
2008-01-21 16:16 ` Arjan van de Ven [this message]
2008-01-18 17:40 ` [patch 2/3] Latencytop instrumentations part 1 Arjan van de Ven
2008-01-18 22:26 ` Frank Ch. Eigler
2008-01-18 22:33 ` Arjan van de Ven
2008-01-18 22:47 ` Arnaldo Carvalho de Melo
2008-01-18 23:11 ` Frank Ch. Eigler
2008-01-18 23:20 ` Arjan van de Ven
2008-01-18 17:42 ` [patch 3/3] LatencyTOP instrumentations part 2 Arjan van de Ven
2008-01-18 18:27 ` [Announce] Development release 0.1 of the LatencyTOP tool Roberto Fichera
2008-01-18 18:35 ` Arjan van de Ven
2008-01-18 18:46 ` Roberto Fichera
2008-01-18 19:02 ` Zan Lynx
2008-01-19 5:07 ` Andi Kleen
2008-01-19 5:16 ` Arjan van de Ven
2008-01-19 5:27 ` Andi Kleen
2008-01-19 5:25 ` Arjan van de Ven
2008-01-19 5:33 ` Andi Kleen
2008-01-19 5:34 ` Arjan van de Ven
2008-01-19 6:08 ` Andi Kleen
2008-01-19 5:37 ` [Announce] Development release 0.1 of the LatencyTOP tool II Andi Kleen
2008-01-21 0:52 ` Development release 0.1 of the LatencyTOP tool KOSAKI Motohiro
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