From: "David S. Miller" <davem@davemloft.net>
To: John Heffner <jheffner@psc.edu>
Cc: netdev@oss.sgi.com, shemminger@osdl.org, ak@muc.de, baruch@ev-en.org
Subject: Re: [RFC] TCP congestion schedulers
Date: Tue, 29 Mar 2005 12:03:06 -0800 [thread overview]
Message-ID: <20050329120306.558cea0c.davem@davemloft.net> (raw)
In-Reply-To: <Pine.LNX.4.58.0503291422100.3256@dexter.psc.edu>
On Tue, 29 Mar 2005 14:32:33 -0500 (EST)
John Heffner <jheffner@psc.edu> wrote:
> The motivation for my question is that I get very unpredictable
> performance over loopback with UP for all architectures, often varying by
> more than a factor of two. I haven't really tried to track down the
> cause, but an important characteristic seems to be that the greater the
> differential between the CPU utilization of the sender and the receiver,
> the slower the throughput. (But I'm not sure if there's a causal relation
> here.) Maybe this is simply scheduler strangeness, since it doesn't seem
> to be an issue that I've noticed on SMP. Has anyone seen this or know
> offhand what's going on?
It could be L2 cache-coloring effects as well. Try to keep the working
set size smaller than the L2 cache size of the cpu you are on.
next prev parent reply other threads:[~2005-03-29 20:03 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-02-23 21:30 [PATCH] select congestion control with one sysctl Baruch Even
2005-02-23 21:57 ` David S. Miller
2005-02-24 0:23 ` Stephen Hemminger
2005-02-24 0:33 ` David S. Miller
2005-02-26 9:41 ` Arnaldo Carvalho de Melo
[not found] ` <421D30FA.1060900@ev-en.org>
[not found] ` <20050225120814.5fa77b13@dxpl.pdx.osdl.net>
[not found] ` <20050309210442.3e9786a6.davem@davemloft.net>
[not found] ` <4230288F.1030202@ev-en.org>
[not found] ` <20050310182629.1eab09ec.davem@davemloft.net>
[not found] ` <20050311120054.4bbf675a@dxpl.pdx.osdl.net>
[not found] ` <20050311201011.360c00da.davem@davemloft.net>
2005-03-14 23:17 ` [RFC] TCP congestion schedulers Stephen Hemminger
2005-03-15 19:54 ` John Heffner
2005-03-15 22:16 ` John Heffner
2005-03-18 4:12 ` David S. Miller
2005-03-18 12:53 ` Arnaldo Carvalho de Melo
2005-03-18 13:43 ` jamal
2005-03-18 16:13 ` Arnaldo Carvalho de Melo
2005-03-18 16:45 ` Stephen Hemminger
2005-03-18 16:59 ` Arnaldo Carvalho de Melo
2005-03-19 20:19 ` Andi Kleen
2005-03-21 21:25 ` John Heffner
2005-03-21 21:51 ` David S. Miller
2005-03-21 22:30 ` Baruch Even
2005-03-22 0:10 ` Rick Jones
2005-03-22 1:41 ` Olaf Kirch
2005-03-22 7:41 ` Andi Kleen
2005-03-28 23:51 ` Stephen Hemminger
2005-03-29 15:25 ` Andi Kleen
2005-03-29 17:17 ` Stephen Hemminger
2005-03-29 18:58 ` Rick Jones
2005-03-30 9:41 ` Matt Mackall
2005-03-29 19:32 ` John Heffner
2005-03-29 20:03 ` David S. Miller [this message]
2005-03-29 20:09 ` Rick Jones
2005-04-08 19:33 ` John Heffner
2005-04-08 20:20 ` Rick Jones
2005-02-24 1:05 ` [PATCH] select congestion control with one sysctl Daniele Lacamera
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=20050329120306.558cea0c.davem@davemloft.net \
--to=davem@davemloft.net \
--cc=ak@muc.de \
--cc=baruch@ev-en.org \
--cc=jheffner@psc.edu \
--cc=netdev@oss.sgi.com \
--cc=shemminger@osdl.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 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).