From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [PATCH kvm-unit-tests] pmu: fixes for Sandy Bridge hosts Date: Mon, 03 Jun 2013 09:44:08 +0200 Message-ID: <51AC4948.8050605@redhat.com> References: <1369935788-19069-1-git-send-email-pbonzini@redhat.com> <20130602153209.GJ24773@redhat.com> <51AC38A9.5010703@redhat.com> <20130603063854.GU4725@redhat.com> <51AC40FE.5020005@redhat.com> <20130603073850.GX4725@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org To: Gleb Natapov Return-path: Received: from mx1.redhat.com ([209.132.183.28]:4410 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751350Ab3FCHoU (ORCPT ); Mon, 3 Jun 2013 03:44:20 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r537iKk7003418 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Mon, 3 Jun 2013 03:44:20 -0400 In-Reply-To: <20130603073850.GX4725@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: Il 03/06/2013 09:38, Gleb Natapov ha scritto: >> > Turbo boost could also contribute to lowering the number of cycles; a >> > boosted processor has ref cpu cycles that are _longer_ than the regular >> > cycles (thus they count in smaller numbers). Maybe that's why "core >> > cycles" didn't go below N. >> > > "core cycles" are subject to Turbo boost changes, not ref cycles. Since > instruction are executed at core frequency ref cpu cycles count may be > indeed smaller. Yes, that's what I was trying to say. :) Paolo