From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony Liguori Subject: Re: [PATCH] qemu-kvm: introduce cpu_start/cpu_stop commands Date: Mon, 22 Nov 2010 17:44:44 -0600 Message-ID: <4CEB006C.8010407@linux.vnet.ibm.com> References: <1290466818-5230-1-git-send-email-aliguori@us.ibm.com> <20101122230405.GB10050@sequoia.sous-sol.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Anthony Liguori , qemu-devel@nongnu.org, kvm@vger.kernel.org To: Chris Wright Return-path: Received: from e33.co.us.ibm.com ([32.97.110.151]:60773 "EHLO e33.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757815Ab0KVXoz (ORCPT ); Mon, 22 Nov 2010 18:44:55 -0500 Received: from d03relay01.boulder.ibm.com (d03relay01.boulder.ibm.com [9.17.195.226]) by e33.co.us.ibm.com (8.14.4/8.13.1) with ESMTP id oAMNdG3E004764 for ; Mon, 22 Nov 2010 16:39:16 -0700 Received: from d03av06.boulder.ibm.com (d03av06.boulder.ibm.com [9.17.195.245]) by d03relay01.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id oAMNiqUx163134 for ; Mon, 22 Nov 2010 16:44:52 -0700 Received: from d03av06.boulder.ibm.com (loopback [127.0.0.1]) by d03av06.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id oAMNmxIE025677 for ; Mon, 22 Nov 2010 16:48:59 -0700 In-Reply-To: <20101122230405.GB10050@sequoia.sous-sol.org> Sender: kvm-owner@vger.kernel.org List-ID: On 11/22/2010 05:04 PM, Chris Wright wrote: > * Anthony Liguori (aliguori@us.ibm.com) wrote: > >> qemu-kvm vcpu threads don't response to SIGSTOP/SIGCONT. Instead of teaching >> them to respond to these signals, introduce monitor commands that stop and start >> individual vcpus. >> > In the past SIGSTOP has introduced time skew. Have you verified this > isn't an issue. > Time skew is a big topic. Are you talking about TSC drift, pit/rtc/hpet drift, etc? It's certainly going to stress periodic interrupt catch up code. Regards, Anthony Liguori > thanks, > -chris >