From: Ingo Molnar <mingo@elte.hu>
To: David Miller <davem@davemloft.net>
Cc: johnpol@2ka.mipt.ru, nickpiggin@yahoo.com.au, wenji@fnal.gov,
akpm@osdl.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [patch 1/4] - Potential performance bottleneck for Linxu TCP
Date: Thu, 30 Nov 2006 21:30:26 +0100 [thread overview]
Message-ID: <20061130203026.GD14696@elte.hu> (raw)
In-Reply-To: <20061130.122258.68041055.davem@davemloft.net>
* David Miller <davem@davemloft.net> wrote:
> I want to point out something which is slightly misleading about this
> kind of analysis.
>
> Your disk I/O speed doesn't go down by a factor of 10 just because 9
> other non disk I/O tasks are running, yet for TCP that's seemingly OK
> :-)
disk I/O is typically not CPU bound, and i believe these TCP tests /are/
CPU-bound. Otherwise there would be no expiry of the timeslice to begin
with and the TCP receiver task would always be boosted to 'interactive'
status by the scheduler and would happily chug along at 500 mbits ...
(and i grant you, if a disk IO test is 20% CPU bound in process context
and system load is 10, then the scheduler will throttle that task quite
effectively.)
Ingo
next prev parent reply other threads:[~2006-11-30 20:31 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-11-30 1:56 [patch 1/4] - Potential performance bottleneck for Linxu TCP Wenji Wu
2006-11-30 2:19 ` David Miller
2006-11-30 6:17 ` Ingo Molnar
2006-11-30 6:30 ` David Miller
2006-11-30 6:47 ` Ingo Molnar
2006-11-30 7:12 ` David Miller
2006-11-30 7:35 ` Ingo Molnar
2006-11-30 9:52 ` Evgeniy Polyakov
2006-11-30 10:07 ` Nick Piggin
2006-11-30 10:22 ` Evgeniy Polyakov
2006-11-30 10:32 ` Ingo Molnar
2006-11-30 17:04 ` Wenji Wu
2006-11-30 20:20 ` Ingo Molnar
2006-11-30 20:58 ` Wenji Wu
2006-11-30 20:22 ` David Miller
2006-11-30 20:30 ` Ingo Molnar [this message]
2006-11-30 20:38 ` David Miller
2006-11-30 20:49 ` Ingo Molnar
2006-11-30 20:54 ` Ingo Molnar
2006-11-30 20:55 ` David Miller
2006-11-30 20:14 ` David Miller
2006-11-30 20:42 ` Wenji Wu
2006-12-01 9:53 ` Evgeniy Polyakov
2006-12-01 23:18 ` David Miller
2006-11-30 6:56 ` Ingo Molnar
2006-11-30 16:08 ` Wenji Wu
2006-11-30 20:06 ` David Miller
2006-11-30 9:33 ` Christoph Hellwig
2006-11-30 16:51 ` Lee Revell
-- strict thread matches above, loose matches on Subject: below --
2006-11-30 2:02 Wenji Wu
2006-11-30 6:19 ` Ingo Molnar
2006-11-29 23:27 [Changelog] " Wenji Wu
2006-11-29 23:28 ` [patch 1/4] " Wenji Wu
2006-11-30 0:53 ` David Miller
2006-11-30 1:08 ` Andrew Morton
2006-11-30 1:13 ` David Miller
2006-11-30 6:04 ` Mike Galbraith
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=20061130203026.GD14696@elte.hu \
--to=mingo@elte.hu \
--cc=akpm@osdl.org \
--cc=davem@davemloft.net \
--cc=johnpol@2ka.mipt.ru \
--cc=linux-kernel@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=nickpiggin@yahoo.com.au \
--cc=wenji@fnal.gov \
/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;
as well as URLs for NNTP newsgroup(s).