2.4 Kernel and Hyperthreading (was Re: [Asterisk-Users] P4 processor

[SW]

>but if I disable hyperthreading (noht on the kernel line in lilo/grub)

Could the same result could be obtained if hyperthreading is disabled from
the BIOS ?
Supermicro Motherboards (most Phoneix based) have this option

Also, would we see same pops and clicks in a dual CPU box (Zeon) then ?

SW


Message: 1
Date: Wed, 07 Jan 2004 14:32:16 -0500
From: Jeremy McNamara <jj at nufone.net>
To: asterisk-users at lists.digium.com
Subject: 2.4 Kernel and Hyperthreading (was Re: [Asterisk-Users] P4
processor
 with Hyperthreading and Asterisk)
Reply-To: asterisk-users at lists.digium.com

mattf wrote:

>Is Asterisk's high memory usage canceling out most of the performance
gained
>by using HT?
>
>
>

In my experience, I've found that hyperthreading is a major problem on
Linux Kernel 2.4.   If I turn on hyperthreading and start to load up an
Asterisk box we get ratty sounding audio along with pops, clicks and
ticks, but if I disable hyperthreading (noht on the kernel line in
lilo/grub) and all of those anomalies go away and the box scales a whole
lot higher.

The problem is that the 2.4 Kernel sees the one hyperthreaded processor
as two totally separate processors, so the 2.4 kernel tends to mess up,
badly, when scheduling the processing.

This problem was delt with in the 2.5 kernel and i've been told by quite
a few trusted people that it works flawlessly, but i'm not about to run
a unstable kernel (or even anything less than like 2.6.14) on any of my
production boxes.


Jeremy McNamara