From: Andi Kleen <ak@muc.de>
To: "Chen, Kenneth W" <kenneth.w.chen@intel.com>
Cc: <linux-kernel@vger.kernel.org>, <axboe@suse.de>
Subject: Re: Direct io on block device has performance regression on 2.6.x kernel
Date: Thu, 10 Mar 2005 00:23:09 +0100 [thread overview]
Message-ID: <m1r7iov1ya.fsf@muc.de> (raw)
In-Reply-To: <200503092218.j29MICg26503@unix-os.sc.intel.com> (Kenneth W. Chen's message of "Wed, 9 Mar 2005 14:18:12 -0800")
"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.
-Andi
next prev parent reply other threads:[~2005-03-09 23:26 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-03-09 22:18 Direct io on block device has performance regression on 2.6.x kernel Chen, Kenneth W
2005-03-09 23:23 ` Andi Kleen [this message]
2005-03-09 23:52 ` Jesse Barnes
2005-03-09 23:52 ` Jesse Barnes
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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=m1r7iov1ya.fsf@muc.de \
--to=ak@muc.de \
--cc=axboe@suse.de \
--cc=kenneth.w.chen@intel.com \
--cc=linux-kernel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.