From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Jones Subject: Re: Detection of HyperThreading Date: Mon, 2 May 2011 12:15:57 -0400 Message-ID: <20110502161557.GA25722@redhat.com> References: Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: Sender: cpufreq-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Pieter De Wit Cc: cpufreq@vger.kernel.org On Mon, May 02, 2011 at 03:47:30PM +1200, Pieter De Wit wrote: > Hello Guys, > > I found something quite weird over the weekend. I have a few machines that > claim they have HT (using cat /proc/cpuinfo). These machines doesn't > really support HT (both with the number of threads and Intel's website) > > I was wondering: > > a) Is this the right list to send to (Sorry if not) no, this list is for cpu frequency scaling. linux-kernel would have been more appropriate. > and > > b) How is the HT flag detected ? > > CPU's like the Core2 Duo E6300 doesn't have HT, but yet the flag is > displayed ? See http://ark.intel.com/Product.aspx?id=27248 for info. I can > send a dump of /proc/cpuinfo later from home. the 'ht' flag in /proc/cpuinfo means "this cpu knows how to report how many siblings it has". On a CPU which doesn't have hyperthreading, that number will be 0. Dave