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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 7A602C04AB6 for ; Tue, 28 May 2019 18:25:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5BF7F208CB for ; Tue, 28 May 2019 18:25:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728083AbfE1SZK (ORCPT ); Tue, 28 May 2019 14:25:10 -0400 Received: from mga18.intel.com ([134.134.136.126]:64042 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726576AbfE1SZK (ORCPT ); Tue, 28 May 2019 14:25:10 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 28 May 2019 11:24:58 -0700 X-ExtLoop1: 1 Received: from linux.intel.com ([10.54.29.200]) by orsmga005.jf.intel.com with ESMTP; 28 May 2019 11:24:58 -0700 Received: from [10.254.95.162] (kliang2-mobl.ccr.corp.intel.com [10.254.95.162]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by linux.intel.com (Postfix) with ESMTPS id 99E4B580372; Tue, 28 May 2019 11:24:57 -0700 (PDT) From: "Liang, Kan" Subject: Re: [PATCH 4/9] perf/x86/intel: Support hardware TopDown metrics To: Peter Zijlstra Cc: 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, ak@linux.intel.com References: <20190521214055.31060-1-kan.liang@linux.intel.com> <20190521214055.31060-5-kan.liang@linux.intel.com> <20190528134845.GQ2623@hirez.programming.kicks-ass.net> Message-ID: <2d693635-9697-2cf5-54dc-b91da4dfd14f@linux.intel.com> Date: Tue, 28 May 2019 14:24:56 -0400 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: <20190528134845.GQ2623@hirez.programming.kicks-ass.net> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 5/28/2019 9:48 AM, Peter Zijlstra wrote: > On Tue, May 21, 2019 at 02:40:50PM -0700, kan.liang@linux.intel.com wrote: >> diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h >> index b980b9e95d2a..0d7081434d1d 100644 >> --- a/include/linux/perf_event.h >> +++ b/include/linux/perf_event.h >> @@ -133,6 +133,11 @@ struct hw_perf_event { >> >> struct hw_perf_event_extra extra_reg; >> struct hw_perf_event_extra branch_reg; >> + >> + u64 saved_metric; >> + u64 saved_slots; >> + u64 last_slots; >> + u64 last_metric; > > This is really sad, and I'm thinking much of that really isn't needed > anyway, due to how you're not using some of the other fields. If we don't cache the value, we have to update all metrics events when reading any metrics event. I think that could bring high overhead. Thanks, Kan > >> }; >> struct { /* software */ >> struct hrtimer hrtimer; >> -- >> 2.14.5 >>