From mboxrd@z Thu Jan 1 00:00:00 1970 From: Zdenek Kaspar Subject: Re: Windows guest CPU socket/core recognition Date: Tue, 18 Aug 2009 17:12:42 +0200 Message-ID: <4A8AC4EA.6070309@gmail.com> References: <4A8A1FE3.10001@gmail.com> <200908180200.38713.iggy@theiggy.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-2 Content-Transfer-Encoding: 7bit Cc: Dor Laor , kvm@vger.kernel.org To: Brian Jackson Return-path: Received: from mail-fx0-f215.google.com ([209.85.220.215]:61275 "EHLO mail-fx0-f215.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750925AbZHRPMo (ORCPT ); Tue, 18 Aug 2009 11:12:44 -0400 Received: by fxm11 with SMTP id 11so343836fxm.39 for ; Tue, 18 Aug 2009 08:12:44 -0700 (PDT) In-Reply-To: <200908180200.38713.iggy@theiggy.com> Sender: kvm-owner@vger.kernel.org List-ID: Brian Jackson napsal(a): > On Monday 17 August 2009 22:28:35 Zdenek Kaspar wrote: >> Hello everyone, >> >> I guess I'm not the first one who hit the problem with Microsoft's >> licensing model.. >> >> Nowadays the common single or dual quad-core workstation can't be fully >> used because it's limited by example: license up to 2 physical >> processors. Such VM acts like 4-way or 8-way machine. > > > Nine times out of ten, a single cpu guest is going to be a better option than > a smp/multie core guest. I've seen idle windows guests go from using nearly > 200% cpu for -smp 2 to ~5-10% for -smp 1. Unless your guest is actually using > all that cpu all the time, you're going to be wasting a decent amount of > cycles. Yes, without proper use it's waste. My guest is 64bit and represents node in computing cluster working on assigned jobs (not MPI etc..) >> Is there any way howto expose CPUs differently for this kind of problem? > > > There have been patches (from Andre Pryzwara and maybe others) to support > multi-core vs mult-socket smp. I will check these patches, thank you (and Dor Laor) for the hint!