From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Cure Subject: Re: performance trouble Date: Thu, 22 Mar 2012 09:31:55 +0100 Message-ID: <20120322083155.GW12293@nfs-rbx.ovh.net> References: <20120222163356.GE26955@nfs-rbx.ovh.net> <20120223083807.GA17505@redhat.com> <20120316101331.GM12293@nfs-rbx.ovh.net> <20120319105134.GA27928@redhat.com> <20120320093220.GS12293@nfs-rbx.ovh.net> <20120320094541.GH22368@redhat.com> <20120320111839.GT12293@nfs-rbx.ovh.net> <20120320123821.GL22368@redhat.com> <20120321111001.GV12293@nfs-rbx.ovh.net> <4F6A1056.1020904@dlh.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Gleb Natapov , Avi Kivity , kvm@vger.kernel.org, Vadim Rozenfeld To: Peter Lieven Return-path: Received: from gandalf.cure.nom.fr ([91.121.137.146]:52840 "EHLO gandalf.cure.nom.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756516Ab2CVIfV (ORCPT ); Thu, 22 Mar 2012 04:35:21 -0400 Content-Disposition: inline In-Reply-To: <4F6A1056.1020904@dlh.net> Sender: kvm-owner@vger.kernel.org List-ID: Le Wed, Mar 21, 2012 at 06:31:02PM +0100, Peter Lieven ecrivait : > > please keep in mind, that setting -hypervisor, disabling hpet and only > one vcpu > makes windows use tsc as clocksource. you have to make sure, that your vm > is not switching between physical sockets on your system and that you have > constant_tsc feature to have a stable tsc between the cores in the > same socket. its also likely that the vm will crash when live migrated. ok, yet I "only" have disable hpet and use 1vcpu. for the switching I need to pin the vcpu on 1 physical proc, right ? for constant_tsc, how can I check if I use it ? for live migration : what is the "feature" that cause trouble : -hypervisor, hpet, vcpu or all ? David.