From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Andrew Theurer <habanero@us.ibm.com>
Cc: linux-kernel@vger.kernel.org, Marcelo Tosatti <marcelo@conectiva.com.br>
Subject: Re: Linux 2.4.19-rc3 (hyperthreading)
Date: 29 Jul 2002 22:28:42 +0100 [thread overview]
Message-ID: <1027978122.4050.22.camel@irongate.swansea.linux.org.uk> (raw)
In-Reply-To: <200207291454.30076.habanero@us.ibm.com>
On Mon, 2002-07-29 at 20:54, Andrew Theurer wrote:
> I would caution against having hyperthreading on by default in the 2.4.19
> release. I am seeing a significant degrade in network workloads on P4 with
> hyperthreading on. On 2.4.19-pre10, I get 788 Mbps on NetBench, but on
> 2.4.19-rc1 (and probably rc3, should know in an hour), I get 690 Mbps. It is
> clearly a hyperthreading/interrupt routing issue. On this system (4 x P4),
Quite possibly. I've just merged the O(1) scheduler load balancing fixes
for the hyperthreading stuff, rc3 uses the old scheduler so that isnt
your problem. For most workloads I see a speed up. The more cache
optimised the workload the less the speedup.
Its quite possible the irq routing ought to be smarter, at the moment
I'm not sure of the best approaches.
next prev parent reply other threads:[~2002-07-29 20:09 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-07-29 19:54 Linux 2.4.19-rc3 (hyperthreading) Andrew Theurer
2002-07-29 21:28 ` Alan Cox [this message]
2002-07-29 20:38 ` Andrea Arcangeli
2002-07-29 23:45 ` Andrea Arcangeli
2002-07-29 23:51 ` Rik van Riel
2002-07-30 0:04 ` Andrea Arcangeli
2002-07-30 0:09 ` J.A. Magallon
2002-07-30 0:32 ` Andrea Arcangeli
2002-07-31 3:08 ` Bill Davidsen
2002-07-31 12:43 ` Rik van Riel
2002-07-31 14:16 ` Sam Vilain
2002-08-01 18:29 ` Ingo Oeser
2002-07-29 20:58 ` Andrew Theurer
2002-07-30 0:37 ` Alan Cox
2002-07-29 23:42 ` Andrew Theurer
2002-07-30 0:56 ` James Bourne
2002-07-30 0:47 ` James Bourne
2002-07-30 1:15 ` Andrew Theurer
2002-07-30 3:09 ` James Bourne
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