From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [patch 2/3] x86: kvmclock: set scheduler clock stable Date: Thu, 28 May 2015 10:39:59 +0200 Message-ID: <5566D45F.5090801@redhat.com> References: <20150528014657.367253422@redhat.com> <20150528014929.457223842@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Cc: Luiz Capitulino , kvm@vger.kernel.org To: Marcelo Tosatti Return-path: Received: from mx1.redhat.com ([209.132.183.28]:37162 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751845AbbE1IkD (ORCPT ); Thu, 28 May 2015 04:40:03 -0400 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (Postfix) with ESMTPS id B34EBC6599 for ; Thu, 28 May 2015 08:40:03 +0000 (UTC) In-Reply-To: <20150528014929.457223842@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 28/05/2015 03:46, Marcelo Tosatti wrote: > + flags = PVCLOCK_COUNTS_FROM_ZERO; If the KVM_FEATURE_CLOCKSOURCE_STABLE_BIT bit is not set, we cannot trust flags at all. So let's just do... > if (kvm_para_has_feature(KVM_FEATURE_CLOCKSOURCE_STABLE_BIT)) > - pvclock_set_flags(PVCLOCK_TSC_STABLE_BIT); > + flags |= PVCLOCK_TSC_STABLE_BIT; - pvclock_set_flags(PVCLOCK_TSC_STABLE_BIT); + pvclock_set_flags(~0); Otherwise looks good. Shall I do the above change and apply? Paolo > + pvclock_set_flags(flags); > + > + cpu = get_cpu(); > + vcpu_time = &hv_clock[cpu].pvti; > + flags = pvclock_read_flags(vcpu_time); > + if (flags & PVCLOCK_COUNTS_FROM_ZERO) > + set_sched_clock_stable(); > + put_cpu(); > }