Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753535AbZFWIQz (ORCPT ); Tue, 23 Jun 2009 04:16:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751729AbZFWIQk (ORCPT ); Tue, 23 Jun 2009 04:16:40 -0400 Received: from mga09.intel.com ([134.134.136.24]:28741 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751691AbZFWIQj (ORCPT ); Tue, 23 Jun 2009 04:16:39 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.42,274,1243839600"; d="scan'208";a="527017220" Date: Tue, 23 Jun 2009 15:59:59 +0800 From: Yong Wang To: eranian@gmail.com Cc: "Wang, Yong Y" , Ingo Molnar , Peter Zijlstra , LKML , Paul Mackerras , Andi Kleen Subject: Re: perf_counter Atom patch Message-ID: <20090623075959.GA23534@ywang-moblin2.bj.intel.com> References: <7c86c4470906221326j6edbf9f3g5d65e96d86aaf7ab@mail.gmail.com> <9F0C1DB20AFA954FA1DA05309350433D7B2584D1@pdsmsx503.ccr.corp.intel.com> <7c86c4470906230045k578bc146wa0e09e4094d937a5@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <7c86c4470906230045k578bc146wa0e09e4094d937a5@mail.gmail.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1283 Lines: 34 On Tue, Jun 23, 2009 at 09:45:03AM +0200, stephane eranian wrote: > > Unfortunately, I don't have a N270 to compare with your results. > We need to verify whether or not N270 implements the fixed counters. > Does it report architected perfmon v3 or v1? > All Atom processors report perfmon v3 as specified in SDM. N270 is no exception. > > The return value of CPUID(0xa) is indeed bogus, too and there is another quirk for that in > > intel_pmu_init() in arch/x86/kernel/cpu/perf_counter.c > > > > x86_pmu.num_counters_fixed ?? ?? ??= max((int)edx.split.num_counters_fixed, 3); > > > > Is this what you were talking about? > > Not quite, because with the max() you'd have a problem on Intel Core > Duo/Solo processors > as they do implement the first generation of architected perfmon and > that one did not have > fixed counters. So you'd have to special case family=6 model=14. That has been taken into account actually. Only perfmon v2 and above are supported as you see in intel_pmu_init(). if (version < 2) return -ENODEV; -- 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/