Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753291Ab0D0PLl (ORCPT ); Tue, 27 Apr 2010 11:11:41 -0400 Received: from mx1.redhat.com ([209.132.183.28]:37621 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751011Ab0D0PLj (ORCPT ); Tue, 27 Apr 2010 11:11:39 -0400 Date: Tue, 27 Apr 2010 12:11:36 -0300 From: Glauber Costa To: Marcelo Tosatti Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, avi@redhat.com Subject: Re: [PATCH 6/6] don't compute pvclock adjustments if we trust the tsc Message-ID: <20100427151136.GJ16166@mothafucka.localdomain> References: <1272303988-21929-1-git-send-email-glommer@redhat.com> <1272303988-21929-2-git-send-email-glommer@redhat.com> <1272303988-21929-3-git-send-email-glommer@redhat.com> <1272303988-21929-4-git-send-email-glommer@redhat.com> <1272303988-21929-5-git-send-email-glommer@redhat.com> <1272303988-21929-6-git-send-email-glommer@redhat.com> <1272303988-21929-7-git-send-email-glommer@redhat.com> <20100427134013.GE18410@amt.cnet> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100427134013.GE18410@amt.cnet> X-ChuckNorris: True User-Agent: Jack Bauer Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1664 Lines: 39 On Tue, Apr 27, 2010 at 10:40:13AM -0300, Marcelo Tosatti wrote: > On Mon, Apr 26, 2010 at 01:46:28PM -0400, Glauber Costa wrote: > > If the HV told us we can fully trust the TSC, skip any > > correction > > > > Signed-off-by: Glauber Costa > > --- > > arch/x86/include/asm/kvm_para.h | 5 +++++ > > arch/x86/include/asm/pvclock-abi.h | 1 + > > arch/x86/kernel/kvmclock.c | 3 +++ > > arch/x86/kernel/pvclock.c | 4 ++++ > > 4 files changed, 13 insertions(+), 0 deletions(-) > > > > diff --git a/arch/x86/include/asm/kvm_para.h b/arch/x86/include/asm/kvm_para.h > > index f019f8c..615ebb1 100644 > > --- a/arch/x86/include/asm/kvm_para.h > > +++ b/arch/x86/include/asm/kvm_para.h > > @@ -21,6 +21,11 @@ > > */ > > #define KVM_FEATURE_CLOCKSOURCE2 3 > > > > +/* The last 8 bits are used to indicate how to interpret the flags field > > + * in pvclock structure. If no bits are set, all flags are ignored. > > + */ > > +#define KVM_FEATURE_CLOCKSOURCE_STABLE_TSC 0xf8 > > + > > #define MSR_KVM_WALL_CLOCK 0x11 > > #define MSR_KVM_SYSTEM_TIME 0x12 > > Please drop this. Its not certain what is the best method to reduce > contention on the global variable. Whatever it is, can be done later. You tell me to drop it, avi tells me to write this, I am happy to pick any one of the two options. Just don't want to get ping-ponged between haveit-dropit. -- 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/