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=-5.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 79933C433DB for ; Mon, 4 Jan 2021 17:35:50 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 35C2B20679 for ; Mon, 4 Jan 2021 17:35:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 35C2B20679 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Type: Content-Transfer-Encoding:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=ZeJVPtWIbkjZG+ZaE5mwQcBMkXf976QRS3DlHomLrjw=; b=j0fiDkyxS2Y5bh8qG5dzWgD/P FCjTHDuUvFomQpyMhaROWP634gU/2NeMRZsUe7ieitbAvbQ8UQn2hq3/d6iDr/lU6tYnGsn549GxM yO9YI8N4vraXPeLozqlV3IKGNFfmizXjpmRklm4HzXMu3GcrcywwoCNXSxqAve44NMbbgIAsVrjLY X1yT3F8s1A2TZUixAMWFOXxqdaj2imnwJnZ19SKYt4uxB+mDfqpiteXVoz7QXqlZJ7cbDmhmbfpnB yZM76p+Ykos6uSbS0zb2XzAjVsiRo6ztebYIUTLe59w7z0fW8rZI5e/38Eg837xMTyzBU4+1Xs5Zj HDZl6y+2w==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kwTk7-0003lL-KN; Mon, 04 Jan 2021 17:34:07 +0000 Received: from foss.arm.com ([217.140.110.172]) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kwTk3-0003km-Pd for linux-arm-kernel@lists.infradead.org; Mon, 04 Jan 2021 17:34:05 +0000 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 CFCD0101E; Mon, 4 Jan 2021 09:33:59 -0800 (PST) Received: from [10.57.38.245] (unknown [10.57.38.245]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id DC2223F66E; Mon, 4 Jan 2021 09:33:57 -0800 (PST) Subject: Re: [PATCH 3/3] rfc: perf: cs_etm: Detect pid in VMID for kernel running at EL2 To: Leo Yan , Denis Nikitin , Mathieu Poirier References: <20201110183313.1823760-1-suzuki.poulose@arm.com> <20201110183313.1823760-4-suzuki.poulose@arm.com> <20201113001105.GA22708@leoy-ThinkPad-X240s> <7e45fd42-0869-cd4f-1eaf-5d48e4464482@arm.com> <20201116094634.GA31795@leoy-ThinkPad-X240s> <0E201888-C3D2-4B9E-A3D5-9F1F62AB2D55@arm.com> <20201223080532.GA26191@leoy-ThinkPad-X240s> From: Suzuki K Poulose Message-ID: <98445ac9-9ef9-e377-034c-c65351348359@arm.com> Date: Mon, 4 Jan 2021 17:33:50 +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: <20201223080532.GA26191@leoy-ThinkPad-X240s> Content-Language: en-GB X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210104_123403_964474_48956DB7 X-CRM114-Status: GOOD ( 28.99 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: al.grant@arm.com, Anshuman Khandual , "coresight@lists.linaro.org" , Daniel Kiss , "linux-arm-kernel@lists.infradead.org" , "mike.leach@linaro.org" Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Leo, On 12/23/20 8:05 AM, Leo Yan wrote: > Hi Denis, > > On Tue, Dec 22, 2020 at 01:57:41AM -0800, Denis Nikitin wrote: > > [...] > >>>> Below is the drafted patch for support PID format in the metadata and >>>> I tested for "perf record" and "perf script" command and can work as >>>> expected. >>>> >>>> P.s. I uploaded the patches into the github [1] and gave some minor >>>> refactoring for your last patch "perf cs-etm: Detect pid in VMID for >>>> kernel running at EL2". >>> >> I have tested the patches on Chrome OS EL2 kernel and they worked fine for >> me. > > Thanks a lot for the testing! > >> Note that "perf cs-etm: Add PID format into metadata" patch breaks perf >> backward compatibility. It may cause a problem in off-target decoding if >> there is a version skew in perf. >> I saw a discussion about perf compatibility in >> https://lists.linaro.org/pipermail/coresight/2020-November/005326.html. >> I understand that perf doesn't guarantee backward compatibility but in fact >> incompatibility issues occur rarely. I think if there is an (easy) way to >> do it the compatibility breakage should be avoided. > > Agreed. After reading the code and I think it's possible to do an extra > checking the length of auxtrace info structure so that can know if > the item CS_ETMV4_PID_FMT is valid or not. Thus we needs to write a > parity function of intel_pt_has() for perf cs-etm; I will try to rework > this patch. > >> This is a critical fix for Chrome OS. Please let me know what you think. > > So are you asking to upstream the changes to mainline kernel? You > could see this patch is owned by Suzuki and I only proposed for one > patch for perf related change. > > Suzuki, could you give some update for the plan of this patch set? > I can help to prepare the perf patch based on Suzuki's plan. I am happy for you to pick up the perf tool changes as needed. I believe there are no changes required for the patches, 1 & 2, which adds the basic kernel and perf tool support. As I have mentioned in the description of this patch, this is clearly an RFC and is a hack. So I am happy that you can fix this properly in perf tool decoding. Mathieu, Are you happy with the proposed series to solve this issue ? I could respin the series on the latest upstream tree if you like. Kind regards Suzuki _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel