Received: by 2002:ac0:e34a:0:0:0:0:0 with SMTP id g10csp534356imn; Thu, 28 Jul 2022 08:09:30 -0700 (PDT) X-Google-Smtp-Source: AGRyM1uZ0xHvcjZdngDWrWN/B53z2ekRGw3pcg3BkR05T8XBkU8t3mq2bDINKR2bT4jJidlDfIGj X-Received: by 2002:a17:902:ec90:b0:16d:2e8f:27cb with SMTP id x16-20020a170902ec9000b0016d2e8f27cbmr27150234plg.12.1659020970107; Thu, 28 Jul 2022 08:09:30 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1659020970; cv=none; d=google.com; s=arc-20160816; b=WWSpvCKUCKkQ035mBfXJxkvmH2kO8cAWH1yAq385s+++sDhnuauK/sHP9VWFJd9J80 Pzd/lNuMBcqg58h6SHCN/8j4pV1eiRuUCk5KWrIKKDBPW0Zhe8m3ZxWTAdn2P2aNxaT7 yXMBxivQzSrygE/ZLsEh8x/2+txrjEJomy8oxvB6g+h3WS4mtlSwK5qc4WLnKQq8Ptxq zAyXEPP+SZthhHceO31juqVKZsTlbGh3TAgGKGiKNOCVUT/zCSY7BuZMKXlQF1QdBlE3 U6IFqFCSj2KZ+eGqzndnMwXrz7owJROcWtCoFIUUQ1jhooA9PXdAnGUlk01swoOnw8ri LCZw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:subject:cc:to:from; bh=fY7eSrtWFjPT8Npv55JqBidfjtDeB633QMsFMaOir3Q=; b=tWae7my/mr8RzCZANQAkD2O0VOp55n5MuqQQVLnhgaI2vL2pLEc5s2GE6XqAs2kvFk n1UqkNKA8ZuTDN0J6/RjHQmON8k7YqmPbsNImT+ZeOrLspHKyCMK4ss9z0bnUpuSxMSR fJZ9G0LuGhQ2/p9mZC/SybS7D/2KYsmRxt+DTV4YcG8PJ6Sr93lOmAsGsfSlFNN8w7bN /TkRcANJpdmcMrvN1t5m6xUZUe9NVIac9NZDxikh62bzqBVfb6aQjsNBdzhp62epmToW 2CBgt0dJGX4KTmSA39KD2GcEcG0sKZObfqsxSKqnzP0fQ08shxNrbokmW14danm6OwxN kV0Q== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=arm.com Return-Path: Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id r13-20020aa7988d000000b005254e555901si844135pfl.90.2022.07.28.08.09.14; Thu, 28 Jul 2022 08:09:30 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=arm.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233338AbiG1Oy5 (ORCPT + 99 others); Thu, 28 Jul 2022 10:54:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33220 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233506AbiG1OyX (ORCPT ); Thu, 28 Jul 2022 10:54:23 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 940686BD7B; Thu, 28 Jul 2022 07:53:44 -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 0086216A3; Thu, 28 Jul 2022 07:53:36 -0700 (PDT) Received: from e126387.arm.com (unknown [10.57.11.24]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 28B163F70D; Thu, 28 Jul 2022 07:53:34 -0700 (PDT) From: carsten.haitzler@foss.arm.com To: linux-kernel@vger.kernel.org Cc: coresight@lists.linaro.org, suzuki.poulose@arm.com, mathieu.poirier@linaro.org, mike.leach@linaro.org, leo.yan@linaro.org, linux-perf-users@vger.kernel.org, acme@kernel.org Subject: [PATCH v5 14/14] perf test: Add relevant documentation about CoreSight testing Date: Thu, 28 Jul 2022 15:52:56 +0100 Message-Id: <20220728145256.2985298-15-carsten.haitzler@foss.arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220728145256.2985298-1-carsten.haitzler@foss.arm.com> References: <20220728145256.2985298-1-carsten.haitzler@foss.arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_HI, SPF_HELO_NONE,SPF_NONE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Carsten Haitzler (Rasterman)" Add/improve documentation helping people get started with CoreSight and perf as well as describe the testing and how it works. Cc: linux-doc@vger.kernel.org Signed-off-by: Carsten Haitzler --- .../trace/coresight/coresight-perf.rst | 160 ++++++++++++++++++ tools/perf/Documentation/arm-coresight.txt | 5 + 2 files changed, 165 insertions(+) create mode 100644 Documentation/trace/coresight/coresight-perf.rst create mode 100644 tools/perf/Documentation/arm-coresight.txt diff --git a/Documentation/trace/coresight/coresight-perf.rst b/Documentation/trace/coresight/coresight-perf.rst new file mode 100644 index 000000000000..401a097aea4b --- /dev/null +++ b/Documentation/trace/coresight/coresight-perf.rst @@ -0,0 +1,160 @@ +.. SPDX-License-Identifier: GPL-2.0 + +================ +CoreSight - Perf +================ + + :Author: Carsten Haitzler + :Date: June 29th, 2022 + +Perf is able to locally access CoreSight trace data and store it to the +output perf data files. This data can then be later decoded to give the +instructions that were traced for debugging or profiling purposes. You +can log such data with a perf record command like:: + + perf record -e cs_etm//u testbinary + +This would run some test binary (testbinary) until it exits and record +a perf.data trace file. That file would have AUX sections if CoreSight +is working correctly. You can dump the content of this file as +readable text with a command like:: + + perf report --stdio --dump -i perf.data + +You should find some sections of this file have AUX data blocks like:: + + 0x1e78 [0x30]: PERF_RECORD_AUXTRACE size: 0x11dd0 offset: 0 ref: 0x1b614fc1061b0ad1 idx: 0 tid: 531230 cpu: -1 + + . ... CoreSight ETM Trace data: size 73168 bytes + Idx:0; ID:10; I_ASYNC : Alignment Synchronisation. + Idx:12; ID:10; I_TRACE_INFO : Trace Info.; INFO=0x0 { CC.0 } + Idx:17; ID:10; I_ADDR_L_64IS0 : Address, Long, 64 bit, IS0.; Addr=0x0000000000000000; + Idx:26; ID:10; I_TRACE_ON : Trace On. + Idx:27; ID:10; I_ADDR_CTXT_L_64IS0 : Address & Context, Long, 64 bit, IS0.; Addr=0x0000FFFFB6069140; Ctxt: AArch64,EL0, NS; + Idx:38; ID:10; I_ATOM_F6 : Atom format 6.; EEEEEEEEEEEEEEEEEEEEEEEE + Idx:39; ID:10; I_ATOM_F6 : Atom format 6.; EEEEEEEEEEEEEEEEEEEEEEEE + Idx:40; ID:10; I_ATOM_F6 : Atom format 6.; EEEEEEEEEEEEEEEEEEEEEEEE + Idx:41; ID:10; I_ATOM_F6 : Atom format 6.; EEEEEEEEEEEN + ... + +If you see these above, then your system is tracing CoreSight data +correctly. + +To compile perf with CoreSight support in the tools/perf directory do:: + + make CORESIGHT=1 + +This requires OpenCSD to build. You may install distribution packages +for the support such as libopencsd and libopencsd-dev or download it +and build yourself. Upstream OpenCSD is located at: + + https://github.com/Linaro/OpenCSD + +For complete information on building perf with CoreSight support and +more extensive usage look at: + + https://github.com/Linaro/OpenCSD/blob/master/HOWTO.md + + +Kernel CoreSight Support +------------------------ + +You will also want CoreSight support enabled in your kernel config. +Ensure it is enabled with:: + + CONFIG_CORESIGHT=y + +There are various other CoreSight options you probably also want +enabled like:: + + CONFIG_CORESIGHT_LINKS_AND_SINKS=y + CONFIG_CORESIGHT_LINK_AND_SINK_TMC=y + CONFIG_CORESIGHT_CATU=y + CONFIG_CORESIGHT_SINK_TPIU=y + CONFIG_CORESIGHT_SINK_ETBV10=y + CONFIG_CORESIGHT_SOURCE_ETM4X=y + CONFIG_CORESIGHT_STM=y + CONFIG_CORESIGHT_CPU_DEBUG=y + CONFIG_CORESIGHT_CTI=y + CONFIG_CORESIGHT_CTI_INTEGRATION_REGS=y + +Please refer to the kernel configuration help for more information. + +Perf test - Verify kernel and userspace perf CoreSight work +----------------------------------------------------------- + +When you run perf test, it will do a lot of self tests. Some of those +tests will cover CoreSight (only if enabled and on ARM64). You +generally would run perf test from the tools/perf directory in the +kernel tree. Some tests will check some internal perf support like: + + Check Arm CoreSight trace data recording and synthesized samples + Check Arm SPE trace data recording and synthesized samples + +Some others will actually use perf record and some test binaries that +are in tests/shell/coresight and will collect traces to ensure a +minimum level of functionality is met. The scripts that launch these +tests are in the same directory. These will all look like: + + CoreSight / ASM Pure Loop + CoreSight / Memcpy 16k 10 Threads + CoreSight / Thread Loop 10 Threads - Check TID + etc. + +These perf record tests will not run if the tool binaries do not exist +in tests/shell/coresight/*/ and will be skipped. If you do not have +CoreSight support in hardware then either do not build perf with +CoreSight support or remove these binaries in order to not have these +tests fail and have them skip instead. + +These tests will log historical results in the current working +directory (e.g. tools/perf) and will be named stats-\*.csv like: + + stats-asm_pure_loop-out.csv + stats-memcpy_thread-16k_10.csv + ... + +These statistic files log some aspects of the AUX data sections in +the perf data output counting some numbers of certain encodings (a +good way to know that it's working in a very simple way). One problem +with CoreSight is that given a large enough amount of data needing to +be logged, some of it can be lost due to the processor not waking up +in time to read out all the data from buffers etc.. You will notice +that the amount of data collected can vary a lot per run of perf test. +If you wish to see how this changes over time, simply run perf test +multiple times and all these csv files will have more and more data +appended to it that you can later examine, graph and otherwise use to +figure out if things have become worse or better. + +This means sometimes these tests fail as they don't capture all the +data needed. This is about tracking quality and amount of data +produced over time and to see when changes to the Linux kernel improve +quality of traces. + +Be aware that some of these tests take quite a while to run, specifically +in processing the perf data file and dumping contents to then examine what +is inside. + +You can change where these csv logs are stored by setting the +PERF_TEST_CORESIGHT_STATDIR environment variable before running perf +test like:: + + export PERF_TEST_CORESIGHT_STATDIR=/var/tmp + perf test + +They will also store resulting perf output data in the current +directory for later inspection like:: + + perf-asm_pure_loop-out.data + perf-memcpy_thread-16k_10.data + ... + +You can alter where the perf data files are stored by setting the +PERF_TEST_CORESIGHT_DATADIR environment variable such as:: + + PERF_TEST_CORESIGHT_DATADIR=/var/tmp + perf test + +You may wish to set these above environment variables if you whish to +keep the output of tests outside of the current working directory for +longer term storage and examination. diff --git a/tools/perf/Documentation/arm-coresight.txt b/tools/perf/Documentation/arm-coresight.txt new file mode 100644 index 000000000000..c117fc50a2a9 --- /dev/null +++ b/tools/perf/Documentation/arm-coresight.txt @@ -0,0 +1,5 @@ +Arm CoreSight Support +===================== + +For full documentation, see Documentation/trace/coresight/coresight-perf.rst +in the kernel tree. -- 2.32.0