From: Hans de Goede <j.w.r.degoede@hhs.nl>
To: David Miller <davem@davemloft.net>
Cc: andi@firstfloor.org, dada1@cosmosbay.com, davej@redhat.com,
netdev@vger.kernel.org
Subject: Re: cat /proc/net/tcp takes 0.5 seconds on x86_64
Date: Thu, 28 Aug 2008 10:12:13 +0200 [thread overview]
Message-ID: <48B65DDD.6020309@hhs.nl> (raw)
In-Reply-To: <20080828.005909.215643947.davem@davemloft.net>
David Miller wrote:
> From: Andi Kleen <andi@firstfloor.org>
> Date: Thu, 28 Aug 2008 09:45:36 +0200
>
>>> When scanning route cache hash table, we can avoid taking locks for empty
>>> buckets.
>> I'm not sure it's worth it in this case. A rcu_read_lock() is a nop
>> (on non preemptible kernel) to very cheap (non atomic increment/decrement in
>> cached task_struct)
>
> It's not one, it's at least two such increments, plus function calls,
> state checks, etc. since this is rcu_read_lock_bh().
>
I'm very happy to see some progress on this and this leading to even more
optimalizations elsewhere,
Thanks guys!
Regards,
Hans
p.s.
Can I please be removed from the CC, thanks!
next prev parent reply other threads:[~2008-08-28 8:01 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <bug-459782-176318@bugzilla.redhat.com>
[not found] ` <200808261549.m7QFnVUN032543@bz-web1.app.phx.redhat.com>
2008-08-26 16:37 ` cat /proc/net/tcp takes 0.5 seconds on x86_64 Dave Jones
2008-08-26 18:32 ` Eric Dumazet
2008-08-26 19:01 ` Hans de Goede
2008-08-26 20:39 ` Eric Dumazet
2008-08-26 20:58 ` Hans de Goede
2008-08-26 21:27 ` Eric Dumazet
2008-08-27 9:14 ` Hans de Goede
2008-08-27 9:05 ` David Miller
2008-08-27 9:45 ` Hans de Goede
2008-08-27 9:39 ` David Miller
2008-08-27 4:19 ` Herbert Xu
2008-08-27 9:07 ` Hans de Goede
2008-08-27 12:41 ` Andi Kleen
2008-08-27 21:29 ` Trent Piepho
2008-08-27 21:47 ` Andi Kleen
2008-08-27 22:54 ` Andi Kleen
2008-08-27 21:29 ` David Miller
2008-08-27 21:48 ` Stephen Hemminger
2008-08-27 22:09 ` David Miller
2008-08-28 6:20 ` Eric Dumazet
2008-08-28 6:51 ` David Miller
2008-08-28 7:13 ` Eric Dumazet
2008-08-28 7:57 ` David Miller
2008-08-28 9:52 ` Eric Dumazet
2008-08-28 7:26 ` Andi Kleen
2008-08-27 22:34 ` Andi Kleen
2008-08-27 22:39 ` David Miller
2008-08-27 22:57 ` Andi Kleen
2008-08-27 23:07 ` David Miller
2008-08-27 23:09 ` Eric Dumazet
2008-08-27 23:15 ` David Miller
2008-08-27 23:35 ` Andi Kleen
2008-08-27 23:43 ` Eric Dumazet
2008-08-27 23:45 ` David Miller
2008-08-28 0:40 ` Eric Dumazet
2008-08-28 7:45 ` Andi Kleen
2008-08-28 7:59 ` David Miller
2008-08-28 8:12 ` Hans de Goede [this message]
2008-08-28 8:04 ` David Miller
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=48B65DDD.6020309@hhs.nl \
--to=j.w.r.degoede@hhs.nl \
--cc=andi@firstfloor.org \
--cc=dada1@cosmosbay.com \
--cc=davej@redhat.com \
--cc=davem@davemloft.net \
--cc=netdev@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.