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Cc: Linus Torvalds <torvalds@osdl.org>, Arjan van de Ven <arjan@infradead.org>,
       Ben Collins <ben.collins@ubuntu.com>, Pavel Machek <pavel@ucw.cz>,
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Subject: Re: [PATCH 1/4] [x86] Add command line option to enable/disable hyper-threading.
Date: Fri, 1 Dec 2006 11:13:27 -0600
To: Alan <alan@lxorguk.ukuu.org.uk>
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From: Mark Rustad <mrustad@gmail.com>
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On Dec 1, 2006, at 10:56 AM, Alan wrote:
>> So I think people have blown those SSL timing attacks _way_ out of
>> proportion, just because it sounds technical and cool.
>>
>> Besides, most of the time you can disable HT in the BIOS, which is  
>> better
>> anyway if you don't want it.
>
> Agreed - but the SSL thing is an irrelevance. The main reason for
> disabling HT (especially on a single core CPU) is because a lot of
> workloads run faster with HT *off*.

Yes. Another way to effectively turn it off is to set maxcpus to the  
number of physical cpus in your system. So far I have not encountered  
a system that that approach does not work on.

-- 
Mark Rustad, MRustad@mac.com