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Date:      Thu, 12 Mar 2009 08:44:13 -0400
From:      John Baldwin <jhb@freebsd.org>
To:        freebsd-smp@freebsd.org, robert@heron.pl
Subject:   Re: only one logical CPU used in Xeon
Message-ID:  <200903120844.13506.jhb@freebsd.org>
In-Reply-To: <200903111501.n2BF1pIj016949@lurza.secnetix.de>
References:  <200903111501.n2BF1pIj016949@lurza.secnetix.de>

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On Wednesday 11 March 2009 11:01:51 am Oliver Fromme wrote:
> Here's how you can see the details in the demsg output:
> The older machine:
> 
>  > Features = 0xbfebfbff <...,HTT,...>
> 
> The "HTT" bit in the features bitmask indicates that the
> processor supports hyperthreading.

No, that flag just means it supports a register where you can ask for the 
total number of threads/cores per package.  Multi-core CPUs that don't have 
hyperthreads have 'HTT' set, but when you read the registers properly you see 
that they have 1 thread per core.

-- 
John Baldwin



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