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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 24254C433FE for ; Tue, 22 Nov 2022 15:41:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232773AbiKVPlc (ORCPT ); Tue, 22 Nov 2022 10:41:32 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50324 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232632AbiKVPl1 (ORCPT ); Tue, 22 Nov 2022 10:41:27 -0500 Received: from out30-45.freemail.mail.aliyun.com (out30-45.freemail.mail.aliyun.com [115.124.30.45]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5904ADF4E; Tue, 22 Nov 2022 07:41:25 -0800 (PST) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R211e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018045170;MF=renyu.zj@linux.alibaba.com;NM=1;PH=DS;RN=19;SR=0;TI=SMTPD_---0VVT0jdJ_1669131678; Received: from 30.32.124.28(mailfrom:renyu.zj@linux.alibaba.com fp:SMTPD_---0VVT0jdJ_1669131678) by smtp.aliyun-inc.com; Tue, 22 Nov 2022 23:41:20 +0800 Message-ID: <180a34c2-f68d-6f4d-da74-7bbb80e9e65c@linux.alibaba.com> Date: Tue, 22 Nov 2022 23:41:18 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.4.1 Subject: Re: [External] : [RFC PATCH v2 1/6] perf vendor events arm64: Add topdown L1 metrics for neoverse-n2 To: James Clark , John Garry Cc: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Andrew Kilroy , Shuai Xue , Zhuo Song , linux-arm-kernel@lists.infradead.org, linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, Will Deacon , Mike Leach , Leo Yan , Ian Rogers References: <1667214694-89839-1-git-send-email-renyu.zj@linux.alibaba.com> <1668411720-3581-2-git-send-email-renyu.zj@linux.alibaba.com> <590ff032-d271-48ee-a4d8-141cc070c335@oracle.com> <75c4f0e6-3f28-a748-e891-7be6016ca28e@oracle.com> <57315669-e6e7-08b8-a252-bc35d4fecc01@arm.com> From: Jing Zhang In-Reply-To: <57315669-e6e7-08b8-a252-bc35d4fecc01@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 在 2022/11/22 下午10:00, James Clark 写道: > > > On 21/11/2022 17:55, John Garry wrote: >> On 21/11/2022 15:17, Jing Zhang wrote: >>> I'm sorry that I misunderstood the purpose of putting metric as >>> arch_std_event at first, >>> and now it works after the modification over your suggestion. >>> >>> But there are also a few questions: >>> >>> 1. The value of the slot in the topdownL1 is various in different >>> architectures, for example, >>> the slot is 5 on neoverse-n2. If I put topdownL1 metric as >>> arch_std_event, then I need to >>> specify the slot to 5 in n2. I can specify slot values in metric like >>> below, but is there any >>> other concise way to do this? >>> >>> diff --git >>> a/tools/perf/pmu-events/arch/arm64/arm/neoverse-n2/metrics.json >>> b/tools/perf/pmu-events/arch/arm64/arm/neoverse-n2/metrics.json >>> index 8ff1dfe..b473baf 100644 >>> --- a/tools/perf/pmu-events/arch/arm64/arm/neoverse-n2/metrics.json >>> +++ b/tools/perf/pmu-events/arch/arm64/arm/neoverse-n2/metrics.json >>> @@ -1,4 +1,23 @@ >>> [ >>> +       { >>> +               "MetricExpr": "5", >>> +               "PublicDescription": "A pipeline slot represents the >>> hardware resources needed to process one uOp", >>> +               "BriefDescription": "A pipeline slot represents the >>> hardware resources needed to process one uOp", >>> +               "MetricName": "slot" >> >> Ehhh....I'm not sure if that is a good idea. Ian or anyone else have an >> opinion on this? It is possible to reuse metrics, so it should work, but... >> >> One problem is that "slot" would show up as a metric, which you would >> not want. >> >> Alternatively I was going to suggest that you can overwrite specific std >> arch event attributes. So for example of frontend_bound, you could have: > > I would agree with not having this and just hard coding the 5 wherever > it's needed. Once we have a few different sets of metrics in place maybe > we can start to look at deduplication, but for now I don't see the value. > >> >> + b/tools/perf/pmu-events/arch/arm64/arm/neoverse-n2/metrics.json >> @@ -0,0 +1,30 @@ >> [ >>     { >>     "ArchStdEvent": "FRONTEND_BOUND", >>         "MetricExpr": "(stall_slot_frontend - cpu_cycles) / (5 * >> cpu_cycles)", >>     }, >> >>> +       } >>> +       { >>> +               "ArchStdEvent": "FRONTEND_BOUND" >>> +       }, >>> +       { >>> +               "ArchStdEvent": "BACKEND_BOUND" >>> +       }, >>> +       { >>> +               "ArchStdEvent": "WASTED" >>> +       }, >>> +       { >>> +               "ArchStdEvent": "RETIRING" >>> +       }, >>> >>> >>> 2. Should I add the topdownL1 metric to >>> tools/perf/pmu-event/recommended.json, >>> or create a new json file to place the general metric? >> >> It would not belong in recommended.json as that is specifically for >> arch-recommended events. It would really just depend on where the value >> comes from, i.e. arm arm or sbsa. >> > > For what we're going to publish shortly we'll be generating a > metrics.json file for each CPU. It will be autogenerated so I don't > think duplication will be an issue and I'm expecting that there will be > differences in the topdown metrics between CPUs anyway. So I would also > vote to not put it in recommended.json > I will create a new sbsa.json file in tools/perf/pmu-events/arch/arm64/ to place metrics that may be common between some CPUs, just like arch_std_event. If the topdown metrics are different in other CPUs, we can overwrite the metric expression. For example: +++ b/tools/perf/pmu-events/arch/arm64/sbsa.json @@ -0,0 +1,9 @@ +[ + { + "MetricExpr": "stall_slot_frontend / (slot * cpu_cycles)", + "PublicDescription": "Frontend bound L1 topdown metric", + "BriefDescription": "Frontend bound L1 topdown metric", + "MetricGroup": "TopDownL1", + "MetricName": "FRONTEND_BOUND" + } +] + b/tools/perf/pmu-events/arch/arm64/arm/neoverse-n2/metrics.json @@ -0,0 +1,30 @@ +[ + { + "ArchStdEvent": "FRONTEND_BOUND", + "MetricExpr": "(stall_slot_frontend - cpu_cycles) / (5 * cpu_cycles)", + } +] In addition, I can also add TLB, Cache, Branch, InstructionMix, PEutilization and other metric groups into sbsa.json, because they are also applicable to neoverse-n1. Above metrics are described in the documentation of neoverse-n1: https://developer.arm.com/documentation/PJDOC-466751330-547673/r4p1/ Thanks, Jing >>> >>> Looking forward to your reply. >>