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=-10.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 01845C433E0 for ; Mon, 11 Jan 2021 07:30:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C71E8227C3 for ; Mon, 11 Jan 2021 07:30:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727589AbhAKH3z (ORCPT ); Mon, 11 Jan 2021 02:29:55 -0500 Received: from foss.arm.com ([217.140.110.172]:48438 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725917AbhAKH3y (ORCPT ); Mon, 11 Jan 2021 02:29:54 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id CFB1131B; Sun, 10 Jan 2021 23:29:08 -0800 (PST) Received: from [10.57.39.145] (unknown [10.57.39.145]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 50EC63F66E; Sun, 10 Jan 2021 23:29:05 -0800 (PST) Subject: Re: [PATCH v1 3/7] perf cs-etm: Calculate per CPU metadata array size To: Leo Yan , Arnaldo Carvalho de Melo , Mathieu Poirier , Mike Leach , Alexander Shishkin , John Garry , Will Deacon , Peter Zijlstra , Ingo Molnar , Mark Rutland , Jiri Olsa , Namhyung Kim , Daniel Kiss , Denis Nikitin , coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <20210109074435.626855-1-leo.yan@linaro.org> <20210109074435.626855-4-leo.yan@linaro.org> From: Suzuki K Poulose Message-ID: <96ec434e-4103-02ac-a05a-761a9ca8cb0d@arm.com> Date: Mon, 11 Jan 2021 07:28:55 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: <20210109074435.626855-4-leo.yan@linaro.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 1/9/21 7:44 AM, Leo Yan wrote: > The metadata array can be extended over time and the tool, if using the > predefined macro (like CS_ETMV4_PRIV_MAX for ETMv4) as metadata array > size to copy data, it can cause compatible issue within different > versions of perf tool. > > E.g. we recorded a data file with an old version tool, afterwards if > use the new version perf tool to parse the file, since the metadata > array has been extended and the macro CS_ETMV4_PRIV_MAX has been > altered, if use it to parse the perf data with old format, this will > lead to mismatch. > > To maintain backward compatibility, this patch calculates per CPU > metadata array size on the runtime, the calculation is based on the > info stored in the data file so that it's reliable. > > Signed-off-by: Leo Yan Looks good to me. Acked-by: Suzuki K Poulose