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Date:      Mon, 31 May 2004 11:35:38 -0400 (EDT)
From:      Daniel Eischen <eischen@vigrid.com>
To:        Chris Elsworth <chris@shagged.org>
Cc:        freebsd-threads@freebsd.org
Subject:   Re: Something we overlooked with MySQL and FreeBSD vs Linux?
Message-ID:  <Pine.GSO.4.10.10405311130250.9642-100000@pcnet5.pcnet.com>
In-Reply-To: <20040531135805.GA60731@shagged.org>

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On Mon, 31 May 2004, Chris Elsworth wrote:

> Sorry to drag this up again :)
> 
> I would check myself, but I don't have access to a HT enabled machine
> with FreeBSD on it anymore to check the now-default setting of this
> sysctl. The last entry in UPDATING records that
> machdep.hlt_logical_cpus is 1, stopping user processes from using the
> logical CPUs.
> 
> Is this still the case? I never knew about that to tweak it. I know, I
> should have read UPDATING.
> 
> If that is still 1 as default, that might explain my 50% performance
> loss on FreeBSD.

I don't either, but FreeBSD's performance on HT machines is not
very good yet.  I seem to recall some earlier reports of disabling
HT and getting better performance.  I think the kernel scheduler
isn't yet tuned to handle HT well.

-- 
DE



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