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From: Andi Kleen <ak@muc.de>
To: Yusuf Goolamabbas <yusufg@outblaze.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: finish_task_switch high in profiles in 2.6.7
Date: Thu, 24 Jun 2004 12:25:32 +0200	[thread overview]
Message-ID: <m3n02tz203.fsf@averell.firstfloor.org> (raw)
In-Reply-To: <2ayz2-1Um-15@gated-at.bofh.it> (Yusuf Goolamabbas's message of "Thu, 24 Jun 2004 11:20:20 +0200")

Yusuf Goolamabbas <yusufg@outblaze.com> writes:

> Hi, I have a fairly busy mailserver which also has a simple iptables
> ruleset (blocking some IP's) running 2.6.7 with the deadline i/o
> scheduler. vmstat was reporting that system time was around 80%. I did
> the following

How many context switches do you get in vmstat?

Most likely you just have far too many of them. readprofile will attribute
most of the cost to finish_task_switch, because that one reenables the 
interrupts (and the profiling only works with interrupts on)

Too many context switches are usually caused by user space.

-Andi 


       reply	other threads:[~2004-06-24 10:25 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <2ayz2-1Um-15@gated-at.bofh.it>
2004-06-24 10:25 ` Andi Kleen [this message]
2004-06-24 10:44   ` finish_task_switch high in profiles in 2.6.7 Yusuf Goolamabbas
2004-06-24 11:36     ` Andi Kleen
2004-06-24 14:05       ` William Lee Irwin III
2004-06-24 21:22         ` William Lee Irwin III
2004-06-24 21:56           ` William Lee Irwin III
2004-06-25  6:51             ` William Lee Irwin III
2004-06-24  9:15 Yusuf Goolamabbas
2004-06-24  9:27 ` Nick Piggin
2004-06-24  9:34   ` Yusuf Goolamabbas
2004-06-24  9:45     ` Nick Piggin
2004-06-24 10:05       ` Yusuf Goolamabbas
2004-06-24 10:10         ` Nick Piggin
2004-06-24 14:30     ` William Lee Irwin III
2004-06-24 15:33       ` William Lee Irwin III

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