From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8E38DC3A5A1 for ; Wed, 28 Aug 2019 16:17:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6E82322DA7 for ; Wed, 28 Aug 2019 16:17:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726866AbfH1QRz (ORCPT ); Wed, 28 Aug 2019 12:17:55 -0400 Received: from mga01.intel.com ([192.55.52.88]:6610 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726395AbfH1QRz (ORCPT ); Wed, 28 Aug 2019 12:17:55 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 28 Aug 2019 09:17:54 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,441,1559545200"; d="scan'208";a="205410102" Received: from tassilo.jf.intel.com (HELO tassilo.localdomain) ([10.7.201.137]) by fmsmga004.fm.intel.com with ESMTP; 28 Aug 2019 09:17:54 -0700 Received: by tassilo.localdomain (Postfix, from userid 1000) id 63BC3301C2F; Wed, 28 Aug 2019 09:17:54 -0700 (PDT) Date: Wed, 28 Aug 2019 09:17:54 -0700 From: Andi Kleen To: Peter Zijlstra Cc: kan.liang@linux.intel.com, acme@kernel.org, mingo@redhat.com, linux-kernel@vger.kernel.org, tglx@linutronix.de, jolsa@kernel.org, eranian@google.com, alexander.shishkin@linux.intel.com Subject: Re: [RESEND PATCH V3 3/8] perf/x86/intel: Support hardware TopDown metrics Message-ID: <20190828161754.GP5447@tassilo.jf.intel.com> References: <20190826144740.10163-1-kan.liang@linux.intel.com> <20190826144740.10163-4-kan.liang@linux.intel.com> <20190828151921.GD17205@worktop.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190828151921.GD17205@worktop.programming.kicks-ass.net> User-Agent: Mutt/1.12.0 (2019-05-25) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > This really doesn't make sense to me; if you set FIXED_CTR3 := 0, you'll > never trigger the overflow there; this then seems to suggest the actual The 48bit counter might overflow in a few hours. -Andi