From: Eric Dumazet <dada1@cosmosbay.com>
To: Andrew Morton <akpm@osdl.org>, linux-kernel@vger.kernel.org
Subject: [PATCH] : struct dentry : place d_hash close to d_parent and d_name to speedup lookups
Date: Thu, 01 Sep 2005 17:44:48 +0200 [thread overview]
Message-ID: <431721F0.6090402@cosmosbay.com> (raw)
In-Reply-To: <20050901035542.1c621af6.akpm@osdl.org>
[-- Attachment #1: Type: text/plain, Size: 772 bytes --]
dentry cache uses sophisticated RCU technology (and prefetching if available)
but touches 2 cache lines per dentry during hlist lookup.
This patch moves d_hash in the same cache line than d_parent and d_name fields
so that :
1) One cache line is needed instead of two.
2) the hlist_for_each_rcu() prefetching has a chance to bring all the needed
data in advance, not only the part that includes d_hash.next.
I also changed one old comment that was wrong for 64bits.
A further optimisation would be to separate dentry in two parts, one that is
mostly read, and one writen (d_count/d_lock) to avoid false sharing on
SMP/NUMA but this would need different field placement depending on 32bits or
64bits platform.
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
[-- Attachment #2: dentry.patch --]
[-- Type: text/plain, Size: 0 bytes --]
next prev parent reply other threads:[~2005-09-01 15:44 UTC|newest]
Thread overview: 57+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-09-01 10:55 2.6.13-mm1 Andrew Morton
2005-09-01 14:22 ` 2.6.13-mm1 Martin J. Bligh
2005-09-01 14:50 ` 2.6.13-mm1 Alan Cox
2005-09-01 20:56 ` 2.6.13-mm1 Joel Schopp
2005-09-01 21:16 ` 2.6.13-mm1 Alan Cox
2005-09-01 21:26 ` 2.6.13-mm1 Joel Schopp
2005-09-01 21:44 ` 2.6.13-mm1 Alan Cox
2005-09-12 16:34 ` tty patches in 2.6.13-mm3 (was Re: 2.6.13-mm1) serue
2005-09-12 16:55 ` Joel Schopp
2005-09-12 17:04 ` 2.6.13-mm1 serue
2005-09-01 14:59 ` 2.6.13-mm1 Adrian Bunk
2005-09-01 15:01 ` [PATCH] mips: remove typedef from struct flock Yoichi Yuasa
2005-09-01 15:38 ` 2.6.13-mm1 Dominik Karall
2005-09-01 16:09 ` 2.6.13-mm1 John Stoffel
2005-09-01 16:28 ` 2.6.13-mm1 Dominik Karall
2005-09-01 17:34 ` 2.6.13-mm1 John Stoffel
2005-09-01 18:05 ` 2.6.13-mm1 Dominik Karall
2005-09-01 18:27 ` 2.6.13-mm1 John Stoffel
2005-09-01 15:44 ` Eric Dumazet [this message]
2005-09-01 15:48 ` [PATCH] : struct dentry : place d_hash close to d_parent and d_name to speedup lookups Eric Dumazet
2005-09-01 17:36 ` Dipankar Sarma
2005-09-01 19:52 ` Eric Dumazet
2005-09-01 17:41 ` 2.6.13-mm1 - drivers/isdn/i4l/isdn_tty broken Damir Perisa
2005-09-01 21:06 ` Alan Cox
2005-09-02 1:05 ` 2.6.13-mm1 - drivers/serial/jsm/jsm_tty broken too Damir Perisa
2005-09-01 21:14 ` 2.6.13-mm1: PCMCIA problem Rafael J. Wysocki
2005-09-01 21:28 ` Andrew Morton
2005-09-02 8:30 ` Rafael J. Wysocki
2005-09-02 8:37 ` Rafael J. Wysocki
2005-09-02 10:43 ` Pavel Machek
2005-09-02 10:58 ` Rafael J. Wysocki
2005-09-02 11:09 ` Andrew Morton
2005-09-02 11:45 ` 2.6.13-mm1: swsusp problem (was: PCMCIA problem) Rafael J. Wysocki
2005-09-02 14:17 ` Rafael J. Wysocki
2005-09-04 14:29 ` 2.6.13-mm1: PCMCIA problem Pavel Machek
2005-09-01 22:19 ` 2.6.13-mm1: broken drivers/video/sis/Makefile Adrian Bunk
2005-09-01 23:24 ` Thomas Winischhofer
2005-09-01 23:25 ` 2.6.13-mm1: misc mwave issues Adrian Bunk
2005-09-02 12:36 ` Alan Cox
2005-09-02 13:57 ` 2.6.13-mm1 Benjamin LaHaise
2005-09-02 20:57 ` 2.6.13-mm1 Andrew Morton
2005-09-06 11:50 ` 2.6.13-mm1 Benjamin LaHaise
2005-09-02 14:30 ` 2.6.13-mm1 Alexander Nyberg
2005-09-02 14:40 ` 2.6.13-mm1 Zwane Mwaikambo
2005-09-03 12:21 ` 2.6.13-mm1 Adrian Bunk
2005-09-03 19:34 ` 2.6.13-mm1 Andrew Morton
2005-09-03 19:54 ` 2.6.13-mm1 Adrian Bunk
2005-09-03 20:06 ` 2.6.13-mm1 Andrew Morton
2005-09-04 20:00 ` 2.6.13-mm1 Adrian Bunk
2005-09-04 21:24 ` 2.6.13-mm1 Jesper Juhl
2005-09-04 21:30 ` 2.6.13-mm1 Andrew Morton
2005-09-04 21:36 ` 2.6.13-mm1 Jesper Juhl
2005-09-07 0:05 ` 2.6.13-mm1 Paul Jackson
2005-09-07 0:32 ` 2.6.13-mm1 Andrew Morton
2005-09-07 0:44 ` 2.6.13-mm1 Jesper Juhl
2005-09-07 2:38 ` 2.6.13-mm1 Paul Jackson
2005-09-04 10:26 ` 2.6.13-mm1 Alexander Nyberg
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=431721F0.6090402@cosmosbay.com \
--to=dada1@cosmosbay.com \
--cc=akpm@osdl.org \
--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.