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 A92AFC53210 for ; Thu, 5 Jan 2023 10:06:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231545AbjAEKGL (ORCPT ); Thu, 5 Jan 2023 05:06:11 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35152 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231370AbjAEKGH (ORCPT ); Thu, 5 Jan 2023 05:06:07 -0500 Received: from out30-57.freemail.mail.aliyun.com (out30-57.freemail.mail.aliyun.com [115.124.30.57]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0A1AB2DC8; Thu, 5 Jan 2023 02:06:05 -0800 (PST) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R611e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018045192;MF=renyu.zj@linux.alibaba.com;NM=1;PH=DS;RN=20;SR=0;TI=SMTPD_---0VYvkzZr_1672913159; Received: from 30.221.147.24(mailfrom:renyu.zj@linux.alibaba.com fp:SMTPD_---0VYvkzZr_1672913159) by smtp.aliyun-inc.com; Thu, 05 Jan 2023 18:06:01 +0800 Message-ID: Date: Thu, 5 Jan 2023 18:05:59 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.6.0 Subject: Re: [PATCH v5 1/6] perf vendor events arm64: Add topdown L1 metrics for neoverse-n2 To: John Garry , Ian Rogers , Xing Zhengjun , Will Deacon , James Clark , Mike Leach , Leo Yan Cc: linux-arm-kernel@lists.infradead.org, linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Andrew Kilroy , Shuai Xue , Zhuo Song References: <1672745976-2800146-1-git-send-email-renyu.zj@linux.alibaba.com> <1672745976-2800146-2-git-send-email-renyu.zj@linux.alibaba.com> <5c5716e5-b2ff-67cd-b608-4eeffa7e04bc@oracle.com> <1f3d53cb-4160-e29d-3934-d6a488d9fd49@linux.alibaba.com> <7aa225df-af25-a6be-9bef-c965488ba43a@oracle.com> From: Jing Zhang In-Reply-To: <7aa225df-af25-a6be-9bef-c965488ba43a@oracle.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 2023/1/5 上午1:26, John Garry 写道: > On 04/01/2023 05:05, Jing Zhang wrote: >> >> >> 在 2023/1/3 下午7:52, John Garry 写道: >>> On 03/01/2023 11:39, Jing Zhang wrote: >>>> The formula of topdown L1 on neoverse-n2 is from ARM sbsa7.0 platform >>>> design document [0], D37-38. >>> >>> I think that I mentioned this before - if the these metrics are coming from an sbsa doc, then they are standard. As such, we can make them "arch std events" and put them in a common json such as sbsa.json, so that other cores may reuse. >>> >>> You don't strictly have to do do this now, but it would be better. >>> >> >> Hi John, > > Hi Jing, > >> >> I would really like to do this, but as discussed earlier, slot is different on each architectures. >> If I do not specify the value of the slot in sbsa.json, then in the json file of n2/v1, I need to >> overwrite each topdown "MetricExpr". In other words, the metrics placed in the sbsa.json file only >> reuse "BriefDescription", "MetricGroup" and "ScaleUnit". So I'm not sure if it's acceptable? > > I don't see a lot of value in that really. > > However, for this value of slot, isn't this discoverable from a system register per core? Quoting the sbsa: "The IMPLEMENTATION DEFINED constant SLOTS is discoverable from the system register PMMIR_EL1.SLOTS." Did you consider how this could be used? > This may be a feasible idea. The value of slots comes from the register PMMIR_EL1, which I can read in /sys/bus/event_source/device/armv8_pmuv3_*/caps/slots. But how do I replace the slots in MetricExpr with the read slots values? Currently I understand that parameters in metricExpr only support events and constants.