From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759633AbdEVQ6O convert rfc822-to-8bit (ORCPT ); Mon, 22 May 2017 12:58:14 -0400 Received: from mga01.intel.com ([192.55.52.88]:42181 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751090AbdEVQ6J (ORCPT ); Mon, 22 May 2017 12:58:09 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.38,377,1491289200"; d="scan'208";a="1172793468" From: "Liang, Kan" To: Peter Zijlstra CC: "mingo@redhat.com" , "eranian@google.com" , "linux-kernel@vger.kernel.org" , "alexander.shishkin@linux.intel.com" , "acme@redhat.com" , "jolsa@redhat.com" , "torvalds@linux-foundation.org" , "tglx@linutronix.de" , "vincent.weaver@maine.edu" , "ak@linux.intel.com" Subject: RE: [PATCH 2/2] perf/x86/intel, watchdog: Switch NMI watchdog to ref cycles on x86 Thread-Topic: [PATCH 2/2] perf/x86/intel, watchdog: Switch NMI watchdog to ref cycles on x86 Thread-Index: AQHS0MiJ97VQOrQ7NkG4uzY0MERdu6H/vyKAgADTFkA= Date: Mon, 22 May 2017 16:58:04 +0000 Message-ID: <37D7C6CF3E00A74B8858931C1DB2F077536F07AC@SHSMSX103.ccr.corp.intel.com> References: <1495213582-3635-1-git-send-email-kan.liang@intel.com> <1495213582-3635-2-git-send-email-kan.liang@intel.com> <20170522120321.e3b7my5lsjue6jpb@hirez.programming.kicks-ass.net> In-Reply-To: <20170522120321.e3b7my5lsjue6jpb@hirez.programming.kicks-ass.net> Accept-Language: zh-CN, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-titus-metadata-40: eyJDYXRlZ29yeUxhYmVscyI6IiIsIk1ldGFkYXRhIjp7Im5zIjoiaHR0cDpcL1wvd3d3LnRpdHVzLmNvbVwvbnNcL0ludGVsMyIsImlkIjoiZGQ4YTU2NzgtYmYzNi00NjZkLThhMTMtNzdkY2Y0NDIzM2FhIiwicHJvcHMiOlt7Im4iOiJDVFBDbGFzc2lmaWNhdGlvbiIsInZhbHMiOlt7InZhbHVlIjoiQ1RQX0lDIn1dfV19LCJTdWJqZWN0TGFiZWxzIjpbXSwiVE1DVmVyc2lvbiI6IjE1LjkuNi42IiwiVHJ1c3RlZExhYmVsSGFzaCI6Im9NdzlKTXdVdE93VWpzQjVvc1BFdEhWZU9EWjNXXC96bytSNzFKaVwvdmhcL2c9In0= x-ctpclassification: CTP_IC dlp-product: dlpe-windows dlp-version: 10.0.102.7 dlp-reaction: no-action x-originating-ip: [10.239.127.40] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > On Fri, May 19, 2017 at 10:06:22AM -0700, kan.liang@intel.com wrote: > > This patch was once merged, but reverted later. > > Because ref-cycles can not be used anymore when watchdog is enabled. > > The commit is 44530d588e142a96cf0cd345a7cb8911c4f88720 > > > > The patch 1/2 has extended the ref-cycles to GP counter. The concern > > should be gone. > > So its not a problem if every Atom prior to Goldmont, and all Core/Core2 > products regress? > > P6 and P4 you've entirely broken, as they don't have REF_CPU_CYCLES at all. > > So no, I don't think this is right even now. > Right, the patch 1/2 doesn't cover all platforms. I will only apply the patch for the platforms, which have ref cycles on GP counters. Thanks, Kan