From: Ingo Molnar <mingo@elte.hu>
To: Sitsofe Wheeler <sitsofe@yahoo.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>,
Arjan van de Ven <arjan@infradead.org>,
linux-kernel@vger.kernel.org,
Steven Rostedt <rostedt@goodmis.org>
Subject: Re: How how latent should non-preemptive scheduling be?
Date: Tue, 23 Sep 2008 13:53:23 +0200 [thread overview]
Message-ID: <20080923115323.GA27240@elte.hu> (raw)
In-Reply-To: <48D88DB4.9020003@yahoo.com>
* Sitsofe Wheeler <sitsofe@yahoo.com> wrote:
> Ingo Molnar wrote:
>> well, since they went away after you enabled CONFIG_PREEMPT=y, they are
>> definitely in-kernel latencies, not any external SMM latencies.
>>
>> I.e. they are inherently fixable. Could you enable:
>>
>> CONFIG_DYNAMIC_FTRACE=y
>> CONFIG_FTRACE_MCOUNT_RECORD=y
>>
>> that should make the traces a lot more verbose - every kernel function
>> executed in the latency path will be logged. That way we'll be able to
>> say which one takes that long.
>
> I do not appear to have the CONFIG_FTRACE_MCOUNT_RECORD option in
> 2.6.27rc7. Is it an option that is only in -tip ?
yeah - it's a new ftrace feature queued up for v2.6.28.
Ingo
next prev parent reply other threads:[~2008-09-23 11:53 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <fa.ERZTl/6uH+mhNoef5fPJKTRjJag@ifi.uio.no>
[not found] ` <fa.PtPFzP5kIJVCCov6YCewrh+o4z4@ifi.uio.no>
[not found] ` <fa.C6WSm5Rh2Nb+Qho7b0qDOZ9RPV8@ifi.uio.no>
[not found] ` <fa.ch6j4qXs/2sFpLkHz5fXrtjTR8c@ifi.uio.no>
[not found] ` <fa.Jx/Ygtm46CVRawlA6OnfYNn6cN0@ifi.uio.no>
2008-09-18 7:26 ` How how latent should non-preemptive scheduling be? Sitsofe Wheeler
[not found] ` <fa.iIHgL48F3T5VAqFw3mqaf9Pzrs4@ifi.uio.no>
[not found] ` <fa.Td8xkKZKMSMghlJmEYefTRVF2kc@ifi.uio.no>
2008-09-19 11:54 ` Sitsofe Wheeler
2008-09-19 14:20 ` Peter Zijlstra
2008-09-22 11:57 ` Ingo Molnar
2008-09-22 12:07 ` Steven Rostedt
2008-09-23 6:33 ` Sitsofe Wheeler
2008-09-23 11:53 ` Ingo Molnar [this message]
2008-09-23 16:30 ` Sitsofe Wheeler
2008-09-23 19:39 ` Sitsofe Wheeler
2008-09-23 22:01 ` Sitsofe Wheeler
2008-09-27 20:48 ` Ingo Molnar
2008-09-28 20:56 ` Sitsofe Wheeler
2008-09-29 8:37 ` Ingo Molnar
2008-09-29 23:11 ` Sitsofe Wheeler
2008-09-30 11:22 ` Ingo Molnar
2008-09-30 13:18 ` Sitsofe Wheeler
2008-10-04 10:50 ` Reading EeePC900 battery info causes stalls when using SLUB (was Re: How how latent should non-preemptive scheduling be?) Sitsofe Wheeler
[not found] <fa.vMKgvqjqmYnI2J40GHoTENeYm8U@ifi.uio.no>
[not found] ` <fa.808p0ZtU9DCpeky4KfNS8Drdw9w@ifi.uio.no>
2008-09-17 21:48 ` How how latent should non-preemptive scheduling be? Sitsofe Wheeler
2008-09-17 21:54 ` Arjan van de Ven
2008-09-17 22:29 ` Sitsofe Wheeler
2008-09-18 2:42 ` Peter Zijlstra
2008-09-18 18:25 ` Sitsofe Wheeler
2008-09-19 8:44 ` Ingo Molnar
2008-09-17 21:18 Sitsofe Wheeler
2008-09-17 21:28 ` Sitsofe Wheeler
2008-09-17 21:34 ` Arjan van de Ven
2008-09-21 20:56 ` Matt Keenan
2008-09-22 6:50 ` Sitsofe Wheeler
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