From: Andrew Morton <akpm@osdl.org>
To: Marcelo Tosatti <marcelo.tosatti@cyclades.com>
Cc: nikita@clusterfs.com, nickpiggin@yahoo.com.au,
Linux-Kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [PATCH]: 1/4 batch mark_page_accessed()
Date: Wed, 1 Dec 2004 17:59:24 -0800 [thread overview]
Message-ID: <20041201175924.75cdcb83.akpm@osdl.org> (raw)
In-Reply-To: <20041201185827.GA5459@dmt.cyclades>
Marcelo Tosatti <marcelo.tosatti@cyclades.com> wrote:
>
> > I don't think that atomic_inc will be particularly
> > costly. generic_file_{write,read}() call find_get_page() just before
> > calling mark_page_accessed(), so cache-line with page reference counter
> > is most likely still exclusive owned by this CPU.
>
> Assuming that is true - what could cause the slowdown?
It isn't true. Atomic ops have a considerable overhead, and this is
unrelated to cache misses. This is especially true of p4's.
Now, that overhead may be justified. Needs more study.
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"aart@kvack.org"> aart@kvack.org </a>
next prev parent reply other threads:[~2004-12-02 1:59 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-11-21 15:44 Nikita Danilov
2004-11-21 21:12 ` Andrew Morton
2004-11-24 10:40 ` Marcelo Tosatti
2004-11-24 16:32 ` Marcelo Tosatti
2004-11-24 21:53 ` Nikita Danilov
2004-11-26 18:58 ` Marcelo Tosatti
2004-11-27 0:37 ` Nick Piggin
2004-11-30 16:29 ` Marcelo Tosatti
2004-12-01 1:33 ` Andrew Morton
2004-11-30 22:57 ` Marcelo Tosatti
2004-12-01 12:23 ` Nikita Danilov
2004-12-01 18:58 ` Marcelo Tosatti
2004-12-02 1:59 ` Andrew Morton [this message]
2004-11-27 10:41 ` Nikita Danilov
2004-11-27 8:19 ` Marcelo Tosatti
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=20041201175924.75cdcb83.akpm@osdl.org \
--to=akpm@osdl.org \
--cc=Linux-Kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=marcelo.tosatti@cyclades.com \
--cc=nickpiggin@yahoo.com.au \
--cc=nikita@clusterfs.com \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox