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 3E8E7C6FD18 for ; Wed, 29 Mar 2023 16:12:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229461AbjC2QML (ORCPT ); Wed, 29 Mar 2023 12:12:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52284 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229457AbjC2QMK (ORCPT ); Wed, 29 Mar 2023 12:12:10 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 00FB05FD6; Wed, 29 Mar 2023 09:11:50 -0700 (PDT) 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 8C8D72F4; Wed, 29 Mar 2023 09:12:12 -0700 (PDT) Received: from [10.57.19.43] (unknown [10.57.19.43]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 7E9B23F6C4; Wed, 29 Mar 2023 09:11:26 -0700 (PDT) Message-ID: <6dcf83ad-bfbc-7e59-7c86-bed334bd09e8@arm.com> Date: Wed, 29 Mar 2023 17:11:24 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.9.0 Subject: Re: [BUG] perf: No samples found when using kcore + coresight Content-Language: en-US To: Leo Yan , Yang Shi Cc: linux-perf-users@vger.kernel.org, LAK , coresight@lists.linaro.org, Linux Kernel Mailing List , mathieu.poirier@linaro.org, adrian.hunter@intel.com, Jiri Olsa , acme@redhat.com, mike.leach@linaro.org, Will Deacon , suzuki.poulose@arm.com References: <8ca2b07e-674e-afb6-ff12-87504f51f252@arm.com> <20230309113851.GF19253@leoy-yangtze.lan> <20230313121420.GB2426758@leoy-yangtze.lan> <20230314003610.GD2426758@leoy-yangtze.lan> From: James Clark In-Reply-To: <20230314003610.GD2426758@leoy-yangtze.lan> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-perf-users@vger.kernel.org On 14/03/2023 00:36, Leo Yan wrote: > On Mon, Mar 13, 2023 at 11:15:44AM -0700, Yang Shi wrote: > > [...] > >>> Just a quick summary, here we have two issues: >>> >>> - With command: >>> perf record -e cs_etm/@tmc_etf63/k --kcore --per-thread \ >>> -- taskset --cpu-list 1 uname", >>> >>> perf doesn't enable "text poke" attribution. >> >> No, it enables "text poke" and perf fails to decode coresight trace >> data too. It doesn't matter whether "--kcore" is after or before "-e >> cs/etm/@tmc_etf63/k". > > Understand now. Thanks for correction, if so we can ignore this one. > > Leo To me it looks like it's only --per-thread and --kcore together that cause the issue. I can't see if that was mentioned previously in this thread. If it is --per-thread that's causing the issue then I think I have an idea why it might be. There are some assumptions and different paths taken in decoding in that mode that aren't correct. It causes some other issues to do with ordering and timestamps as well and I wanted to fix it previously. I wouldn't say that the text-poke change has caused a regression, as decoding in this mode was always a bit buggy. Maybe this is another reason to fix it properly.