From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1Cs43p-0004pk-7N for qemu-devel@nongnu.org; Fri, 21 Jan 2005 14:03:09 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1Cs43o-0004pT-K5 for qemu-devel@nongnu.org; Fri, 21 Jan 2005 14:03:08 -0500 Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Cs40S-000486-2B for qemu-devel@nongnu.org; Fri, 21 Jan 2005 13:59:42 -0500 Received: from [38.113.3.61] (helo=smtp-out.hotpop.com) by monty-python.gnu.org with esmtp (Exim 4.34) id 1Cs3W2-0004cz-LA for qemu-devel@nongnu.org; Fri, 21 Jan 2005 13:28:14 -0500 Received: from phreaker.net (kubrick.hotpop.com [38.113.3.103]) by smtp-out.hotpop.com (Postfix) with SMTP id 77104D3E44B for ; Fri, 21 Jan 2005 18:28:08 +0000 (UTC) Received: from jbrown.mylinuxbox.org (pcp03144805pcs.midval01.tn.comcast.net [68.59.228.236]) by smtp-2.hotpop.com (Postfix) with ESMTP id D15E7D2A099 for ; Fri, 21 Jan 2005 18:28:07 +0000 (UTC) Date: Fri, 21 Jan 2005 13:27:53 -0500 From: "Jim C. Brown" Subject: Re: [Qemu-devel] Hyperthreading in the VM host Message-ID: <20050121182753.GA12080@jbrown.mylinuxbox.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org On Fri, Jan 21, 2005 at 03:52:43PM +0000, Julian Chesterfield wrote: > My understanding is that Qemu does not support hyperthreading in the host > OS. You mean guest OS, right? It shouldn't make a different if the host OS uses it or not. > I'm wondering what the arguments are for and against such support. Is it > in fact architecturally feasible and could there potentially be any performance > gain? It would be easier to implement true SMP emulation inside of qemu. Hyperthreading is just a way to make one CPU look like 2, so it is a way for the PIV to emulate SMP... there is no point in emulating hyperthreading if we can implement SMP inside of qemu. Why go to the trouble of getting one emulated cpu to do the job of 2 when you can just emulate 2 cpus? > > Thanks! > Julian > > > > _______________________________________________ > Qemu-devel mailing list > Qemu-devel@nongnu.org > http://lists.nongnu.org/mailman/listinfo/qemu-devel > -- Infinite complexity begets infinite beauty. Infinite precision begets infinite perfection.