From: Jesse Barnes <jbarnes@engr.sgi.com>
To: Andi Kleen <ak@muc.de>
Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com>,
linux-kernel@vger.kernel.org, axboe@suse.de
Subject: Re: Direct io on block device has performance regression on 2.6.x kernel
Date: Wed, 9 Mar 2005 15:52:41 -0800 [thread overview]
Message-ID: <200503091552.41450.jbarnes@engr.sgi.com> (raw)
In-Reply-To: <m1r7iov1ya.fsf@muc.de>
On Wednesday, March 9, 2005 3:23 pm, Andi Kleen wrote:
> "Chen, Kenneth W" <kenneth.w.chen@intel.com> writes:
> > Just to clarify here, these data need to be taken at grain of salt. A
> > high count in _spin_unlock_* functions do not automatically points to
> > lock contention. It's one of the blind spot syndrome with timer based
> > profile on ia64. There are some lock contentions in 2.6 kernel that
> > we are staring at. Please do not misinterpret the number here.
>
> Why don't you use oprofileÂ>? It uses NMIs and can profile "inside"
> interrupt disabled sections.
Oh, and there are other ways of doing interrupt off profiling by using the
PMU. q-tools can do this I think.
Jesse
next prev parent reply other threads:[~2005-03-10 4:34 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-03-09 22:18 Chen, Kenneth W
2005-03-09 23:23 ` Andi Kleen
2005-03-09 23:52 ` Jesse Barnes
2005-03-09 23:52 ` Jesse Barnes [this message]
2005-03-10 1:00 ` Chen, Kenneth W
2005-03-10 0:57 ` Chen, Kenneth W
-- strict thread matches above, loose matches on Subject: below --
2005-03-10 2:04 Chen, Kenneth W
2005-03-10 1:24 Chen, Kenneth W
2005-03-09 1:53 Chen, Kenneth W
2005-03-09 1:39 Chen, Kenneth W
2005-03-09 6:27 ` Andrew Morton
2005-03-09 17:21 ` Chen, Kenneth W
2005-03-09 20:04 ` Andrew Morton
2005-03-09 21:59 ` Chen, Kenneth W
2005-03-09 22:44 ` Andrew Morton
2005-03-10 1:11 ` Chen, Kenneth W
2005-03-10 1:33 ` Andrew Morton
2005-03-10 1:44 ` Chen, Kenneth W
2005-03-10 2:25 ` Andrew Morton
2005-03-10 3:47 ` Chen, Kenneth W
2005-03-10 4:04 ` David Lang
2005-03-10 4:10 ` Andrew Morton
2005-03-10 4:09 ` Andrew Morton
2005-03-10 18:31 ` Chen, Kenneth W
2005-03-10 20:30 ` Andrew Morton
2005-03-10 21:42 ` Chen, Kenneth W
2005-03-10 22:01 ` Andrew Morton
2005-03-10 4:28 ` Andrew Vasquez
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