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Date:      Sun, 02 Apr 2006 11:34:51 +1200
From:      Mark Kirkwood <markir@paradise.net.nz>
To:        Petri Helenius <pete@he.iki.fi>
Cc:        Eric <ericd@free.fr>, freebsd-smp@freebsd.org, Lucas Holt <luke@foolishgames.com>
Subject:   Re: Low perf with smp
Message-ID:  <442F0E1B.9090505@paradise.net.nz>
In-Reply-To: <442EAA0A.8030704@he.iki.fi>
References:  <009301c65418$cc029f30$65fd24c0@Eric> <64659004-E643-4044-AAED-076E0CC91977@foolishgames.com> <01a901c65493$77ad2740$65fd24c0@Eric> <442DC9B6.2090200@paradise.net.nz> <442EAA0A.8030704@he.iki.fi>

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Petri Helenius wrote:
> Mark Kirkwood wrote:
> 
>>
>> As I understand it, when you activate SMP a more accurate, but slower 
>> timecounter is chosen (typically 'i8254' instead of 'TSC' on intel HW).
> 
> 
> ACPI-fast should be the default with SMP. It's significantly faster than 
> i8254
> 

Yeah - if his Dell has ACPI enabled. However, ACPI-fast is still slower 
than say TSC.

Eric, do you want to show us the output of

$ sysctl kern.timecounter

with and without SMP?

Cheers

Mark



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