linux-kernel - Re: [PATCH 1/4] [x86] Add command line option to enable/disable hyper-threading.

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <D3A09DC0-99E4-4F0F-BFB6-33FD6B4C7766@gmail.com>
Date:	Fri, 1 Dec 2006 11:13:27 -0600
From:	Mark Rustad <mrustad@...il.com>
To:	Alan <alan@...rguk.ukuu.org.uk>
Cc:	Linus Torvalds <torvalds@...l.org>,
	Arjan van de Ven <arjan@...radead.org>,
	Ben Collins <ben.collins@...ntu.com>,
	Pavel Machek <pavel@....cz>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/4] [x86] Add command line option to enable/disable hyper-threading.

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@....com

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/