Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932520Ab1CDUz2 (ORCPT ); Fri, 4 Mar 2011 15:55:28 -0500 Received: from gwu.lbox.cz ([62.245.111.132]:36162 "EHLO gwu.lbox.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932437Ab1CDUz1 (ORCPT ); Fri, 4 Mar 2011 15:55:27 -0500 Date: Fri, 4 Mar 2011 21:55:12 +0100 From: Nikola Ciprich To: Glauber Costa Cc: Zachary Amsden , Avi Kivity , Nikola Ciprich , KVM list , Linux kernel list Subject: Re: regression - 2.6.36 -> 2.6.37 - kvm - 32bit SMP guests don't boot Message-ID: <20110304205512.GB2867@nik-comp.lan> References: <20110228171550.GA2173@nik-comp.lan> <4D6EF536.305@redhat.com> <20110303070652.GG29840@pcnci.linuxbox.cz> <4D6FFE5D.1030401@redhat.com> <20110303210647.GA27691@nik-comp.lan> <4D700F09.9000002@redhat.com> <20110303220155.GB27691@nik-comp.lan> <4D7101AF.6060009@redhat.com> <20110304182733.GA2867@nik-comp.lan> <1299265762.11618.140.camel@mothafucka.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1299265762.11618.140.camel@mothafucka.localdomain> User-Agent: Mutt/1.5.19 (2009-01-05) X-Antivirus: on lbxovapx by Kaspersky antivirus, 4719961 records (last update: 20110304) X-Spam-Score: N/A (trusted relay) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1823 Lines: 58 > Zach, > > I don't understand 100 % the logic behind all your tsc changes. > But kvm-clock-wise, most of the problems we had in the past were related > to the difference in resolution between the tsc and the host clocksource > (hpet, acpi_pm, etc), which in his case, it is a non-issue. > > It does seem to me like some compensation logic kicked in, dismantling > an otherwise good tsc. He does have nonstop_tsc, which means it can't > get any better. > > One thing I noticed when reading the culprit patch in bisect, is that in > vcpu_load(), there were previously a call to > > kvm_request_guest_time_update(vcpu) > > that was removed without a counterpart addition. Any idea about why it > was done? > > Nikola, does adding that line back alleviate the problem for you ? Hello Glauber, kvm_request_guest_time_update seems to have been renamed and then removed since then, but I've added kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu); instead and now the guest boots! So maybe missing clock update is really the culprit here? What do You guys think? n. > > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- ------------------------------------- Ing. Nikola CIPRICH LinuxBox.cz, s.r.o. 28. rijna 168, 709 01 Ostrava tel.: +420 596 603 142 fax: +420 596 621 273 mobil: +420 777 093 799 www.linuxbox.cz mobil servis: +420 737 238 656 email servis: servis@linuxbox.cz ------------------------------------- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/