From: Andi Kleen <ak@suse.de>
To: Willy Tarreau <w@1wt.eu>
Cc: Jesper Dangaard Brouer <hawk@diku.dk>,
Harry Edmon <harry@atmos.washington.edu>,
linux-kernel@vger.kernel.org, netdev@vger.kernel.org
Subject: Re: Network performance degradation from 2.6.11.12 to 2.6.16.20
Date: Mon, 26 Jun 2006 07:23:42 +0200 [thread overview]
Message-ID: <200606260723.43209.ak@suse.de> (raw)
In-Reply-To: <20060625222243.GJ13255@w.ods.org>
> I encountered the same problem on a dual core opteron equipped with a
> broadcom NIC (tg3) under 2.4. It could receive 1 Mpps when using TSC
> as the clock source, but the time jumped back and forth, so I changed
> it to 'notsc', then the performance dropped dramatically to around the
> same value as above with one CPU saturated. I suspect that the clock
> precision is needed by the tg3 driver to correctly decide to switch to
> polling mode, but unfortunately, the performance drop rendered the
> solution so much unusable that I finally decided to use it only in
> uniprocessor with TSC enabled.
2.6 is more clever at this than 2.4. In particular it does the timestamp
for each packet only when actually needed, which is relativelt rare.
Old experiences do not always apply to new kernels.
-Andi
next prev parent reply other threads:[~2006-06-26 5:23 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <4492D5D3.4000303@atmos.washington.edu>
2006-06-17 22:35 ` Network performance degradation from 2.6.11.12 to 2.6.16.20 Andrew Morton
2006-06-17 23:23 ` Harry Edmon
2006-06-17 23:56 ` Andrew Morton
2006-06-18 3:16 ` Stephen Hemminger
2006-06-18 23:23 ` Harry Edmon
2006-06-19 13:54 ` Harry Edmon
2006-06-20 2:11 ` Herbert Xu
2006-06-19 14:47 ` Jesper Dangaard Brouer
2006-06-19 15:24 ` Andi Kleen
2006-06-19 17:34 ` Chris Friesen
2006-06-19 20:39 ` Andi Kleen
2006-06-19 18:24 ` Jesper Dangaard Brouer
2006-06-25 21:51 ` Harry Edmon
2006-06-26 4:20 ` Bill Fink
2006-06-25 22:22 ` Willy Tarreau
2006-06-26 5:23 ` Andi Kleen [this message]
2006-07-04 11:41 ` Jesper Dangaard Brouer
2006-07-04 11:54 ` Andi Kleen
2006-07-10 10:55 ` Jesper Dangaard Brouer
2006-09-16 12:08 ` Vladimir B. Savkin
2006-09-18 8:35 ` Andi Kleen
2006-09-18 9:03 ` Vladimir B. Savkin
2006-09-18 9:58 ` Andi Kleen
2006-09-18 10:29 ` Vladimir B. Savkin
2006-09-18 11:27 ` Andi Kleen
2006-09-18 15:38 ` Alexey Kuznetsov
2006-09-18 15:54 ` Andi Kleen
2006-09-18 16:28 ` Alexey Kuznetsov
2006-09-18 16:50 ` Andi Kleen
2006-09-18 21:03 ` Alexey Kuznetsov
2006-09-18 21:22 ` David Miller
2006-09-18 21:46 ` Alexey Kuznetsov
2006-09-19 5:55 ` Andi Kleen
2006-09-19 20:31 ` Thomas Graf
2006-09-19 20:43 ` Andi Kleen
2006-09-19 5:52 ` Andi Kleen
2006-09-18 21:18 ` Vladimir B. Savkin
2006-09-18 22:00 ` Alexey Kuznetsov
2006-09-18 21:57 ` David Lang
2006-09-19 19:40 ` David Miller
2006-09-19 19:44 ` Stephen Hemminger
2006-09-18 22:03 ` Vladimir B. Savkin
2006-09-19 19:41 ` David Miller
2006-09-19 19:47 ` David Miller
2006-09-22 15:35 ` Alexey Kuznetsov
2006-09-22 15:43 ` Andi Kleen
2006-09-22 16:51 ` Rick Jones
2007-03-06 13:25 ` Packet timestamps (was: Re: Network performance degradation from 2.6.11.12 to 2.6.16.20) Vladimir B. Savkin
2007-03-06 14:38 ` Eric Dumazet
2007-03-06 14:43 ` Vladimir B. Savkin
2007-03-06 15:16 ` Eric Dumazet
2007-03-06 18:15 ` Vladimir B. Savkin
2006-09-18 21:08 ` Network performance degradation from 2.6.11.12 to 2.6.16.20 Vladimir B. Savkin
2006-09-18 14:09 ` David Miller
2006-09-18 14:29 ` Andi Kleen
2006-09-18 15:19 ` Alan Cox
2006-09-18 15:19 ` Andi Kleen
2006-06-19 16:40 ` Harry Edmon
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=200606260723.43209.ak@suse.de \
--to=ak@suse.de \
--cc=harry@atmos.washington.edu \
--cc=hawk@diku.dk \
--cc=linux-kernel@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=w@1wt.eu \
/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).