From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: "Theodore Ts'o" <tytso@mit.edu>
Cc: linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH, RFC] ext4: Use preallocation when reading from the inode table
Date: Tue, 23 Sep 2008 10:16:13 +0100 [thread overview]
Message-ID: <20080923101613.58768083@lxorguk.ukuu.org.uk> (raw)
In-Reply-To: <E1KhvsB-0002Ik-Ex@closure.thunk.org>
On Mon, 22 Sep 2008 20:35:23 -0400
"Theodore Ts'o" <tytso@mit.edu> wrote:
>
> With modern hard drives, reading 64k takes roughly the same time as
> reading a 4k block. So request adjacent inode table blocks to reduce
> the time it takes when iterating over directories (especially when doing
> this in htree sort order) in a cold cache case. With this patch, the
> time it takes to run "git status" on a kernel tree after flushing the
> caches via "echo 3 > /proc/sys/vm/drop_caches", is reduced by 21%.
>
> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Acked-by: Alan Cox <alan@redhat.com>
I'm actually suprised that 16 is the magic tuning number you've used and
a bigger one isn't even more of a win
Alan
next prev parent reply other threads:[~2008-09-23 9:16 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-09-23 0:35 Theodore Ts'o
2008-09-23 9:16 ` Alan Cox [this message]
2008-09-23 11:50 ` Andreas Dilger
2008-09-23 12:18 ` Ric Wheeler
2008-09-24 1:30 ` Theodore Tso
2008-09-24 13:23 ` Ric Wheeler
2008-09-24 14:20 ` Chris Mason
2008-09-24 20:35 ` Theodore Tso
2008-09-25 23:40 ` Andreas Dilger
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=20080923101613.58768083@lxorguk.ukuu.org.uk \
--to=alan@lxorguk.ukuu.org.uk \
--cc=linux-ext4@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=tytso@mit.edu \
/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
all inboxes | Powered by JetHome®