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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2CE28C433EF for ; Tue, 2 Nov 2021 14:07:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 16FF360EDF for ; Tue, 2 Nov 2021 14:07:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230124AbhKBOKV (ORCPT ); Tue, 2 Nov 2021 10:10:21 -0400 Received: from foss.arm.com ([217.140.110.172]:36346 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229557AbhKBOKU (ORCPT ); Tue, 2 Nov 2021 10:10:20 -0400 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 38B34D6E; Tue, 2 Nov 2021 07:07:45 -0700 (PDT) Received: from [10.32.33.50] (e121896.warwick.arm.com [10.32.33.50]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 78D503F7B4; Tue, 2 Nov 2021 07:07:43 -0700 (PDT) Subject: Re: [PATCH 5/5] perf arm-spe: Snapshot mode test To: Leo Yan , German Gomez Cc: linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, John Garry , Will Deacon , Mathieu Poirier , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Mike Leach , linux-arm-kernel@lists.infradead.org, coresight@lists.linaro.org References: <20210916154635.1525-1-german.gomez@arm.com> <20210916154635.1525-5-german.gomez@arm.com> <20211020131339.GG49614@leoy-ThinkPad-X240s> From: James Clark Message-ID: Date: Tue, 2 Nov 2021 14:07:42 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 In-Reply-To: <20211020131339.GG49614@leoy-ThinkPad-X240s> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-perf-users@vger.kernel.org On 20/10/2021 14:13, Leo Yan wrote: > On Thu, Sep 16, 2021 at 04:46:35PM +0100, German Gomez wrote: >> Shell script test_arm_spe.sh has been added to test the recording of SPE >> tracing events in snapshot mode. >> >> Reviewed-by: James Clark >> Signed-off-by: German Gomez >> --- >> tools/perf/tests/shell/test_arm_spe.sh | 91 ++++++++++++++++++++++++++ >> 1 file changed, 91 insertions(+) >> create mode 100755 tools/perf/tests/shell/test_arm_spe.sh >> >> diff --git a/tools/perf/tests/shell/test_arm_spe.sh b/tools/perf/tests/shell/test_arm_spe.sh >> new file mode 100755 >> index 000000000000..9ed817e76f95 >> --- /dev/null >> +++ b/tools/perf/tests/shell/test_arm_spe.sh >> @@ -0,0 +1,91 @@ >> +#!/bin/sh >> +# Check Arm SPE trace data recording and synthesized samples >> + >> +# Uses the 'perf record' to record trace data of Arm SPE events; >> +# then verify if any SPE event samples are generated by SPE with >> +# 'perf script' and 'perf report' commands. >> + >> +# SPDX-License-Identifier: GPL-2.0 >> +# German Gomez , 2021 >> + >> +skip_if_no_arm_spe_event() { >> + perf list | egrep -q 'arm_spe_[0-9]+//' && return 0 >> + >> + # arm_spe event doesn't exist >> + return 2 >> +} >> + >> +skip_if_no_arm_spe_event || exit 2 >> + >> +perfdata=$(mktemp /tmp/__perf_test.perf.data.XXXXX) >> +glb_err=0 >> + >> +cleanup_files() >> +{ >> + rm -f ${perfdata} >> + trap - exit term int >> + kill -2 $$ # Forward sigint to parent > > I understand you copy this code from Arm cs-etm testing, but I found > the sentence 'kill -2 $$' will cause a failure at my side with the > command: > > root@ubuntu:/home/leoy/linux/tools/perf# ./perf test 85 -v > 85: Check Arm SPE trace data recording and synthesized samples : > --- start --- > test child forked, pid 29053 > Recording trace with snapshot mode /tmp/__perf_test.perf.data.uughb > Looking at perf.data file for dumping samples: > Looking at perf.data file for reporting samples: > SPE snapshot testing: PASS > test child finished with -1 > ---- end ---- > Check Arm SPE trace data recording and synthesized samples: FAILED! > > I changed to use below code and looks it works for me: > > if [[ "$1" == "int" ]]; then > kill -SIGINT $$ > fi > if [[ "$1" == "term" ]]; then > kill -SIGTERM $$ > fi > > Thanks, > Leo This is quite interesting. It looks like the issue is caused by the update from dash 0.5.8 on Ubuntu 18 to dash 0.5.10 on Ubuntu 20. Specifically the commit that causes the issue is: commit 9e5cd41d9605e4caaac3aacdc0482f6ee220a298 Author: Herbert Xu Date: Mon May 7 00:40:34 2018 +0800 jobs - Do not block when waiting on SIGCHLD Because of the nature of SIGCHLD, the process may have already been waited on and therefore we must be prepared for the case that wait may block. So ensure that it doesn't by using WNOHANG. Furthermore, multiple jobs may have exited when gotsigchld is set. Therefore we need to wait until there are no zombies left. Lastly, waitforjob needs to be called with interrupts off and the original patch broke that. Fixes: 03876c0743a5 ("eval: Reap zombies after built-in...") Signed-off-by: Herbert Xu This also means that the Coresight shell test will not be working anymore because I added the same trap to it so that it could be run in a loop. I'm going to compare the bahaviour to bash to see which one is doing the right thing and what the correct change to make to fix it is. Or a bug needs to be reported. Thanks James > >> + exit $glb_err >> +} >> + >> +trap cleanup_files exit term int >> + >> +arm_spe_report() { >> + if [ $2 != 0 ]; then >> + echo "$1: FAIL" >> + glb_err=$2 >> + else >> + echo "$1: PASS" >> + fi >> +} >> + >> +perf_script_samples() { >> + echo "Looking at perf.data file for dumping samples:" >> + >> + # from arm-spe.c/arm_spe_synth_events() >> + events="(ld1-miss|ld1-access|llc-miss|lld-access|tlb-miss|tlb-access|branch-miss|remote-access|memory)" >> + >> + # Below is an example of the samples dumping: >> + # dd 3048 [002] 1 l1d-access: ffffaa64999c __GI___libc_write+0x3c (/lib/aarch64-linux-gnu/libc-2.27.so) >> + # dd 3048 [002] 1 tlb-access: ffffaa64999c __GI___libc_write+0x3c (/lib/aarch64-linux-gnu/libc-2.27.so) >> + # dd 3048 [002] 1 memory: ffffaa64999c __GI___libc_write+0x3c (/lib/aarch64-linux-gnu/libc-2.27.so) >> + perf script -F,-time -i ${perfdata} 2>&1 | \ >> + egrep " +$1 +[0-9]+ .* +${events}:(.*:)? +" > /dev/null 2>&1 >> +} >> + >> +perf_report_samples() { >> + echo "Looking at perf.data file for reporting samples:" >> + >> + # Below is an example of the samples reporting: >> + # 73.04% 73.04% dd libc-2.27.so [.] _dl_addr >> + # 7.71% 7.71% dd libc-2.27.so [.] getenv >> + # 2.59% 2.59% dd ld-2.27.so [.] strcmp >> + perf report --stdio -i ${perfdata} 2>&1 | \ >> + egrep " +[0-9]+\.[0-9]+% +[0-9]+\.[0-9]+% +$1 " > /dev/null 2>&1 >> +} >> + >> +arm_spe_snapshot_test() { >> + echo "Recording trace with snapshot mode $perfdata" >> + perf record -o ${perfdata} -e arm_spe// -S \ >> + -- dd if=/dev/zero of=/dev/null > /dev/null 2>&1 & >> + PERFPID=$! >> + >> + # Wait for perf program >> + sleep 1 >> + >> + # Send signal to snapshot trace data >> + kill -USR2 $PERFPID >> + >> + # Stop perf program >> + kill $PERFPID >> + wait $PERFPID >> + >> + perf_script_samples dd && >> + perf_report_samples dd >> + >> + err=$? >> + arm_spe_report "SPE snapshot testing" $err >> +} >> + >> +arm_spe_snapshot_test >> +exit $glb_err >> \ No newline at end of file >> -- >> 2.17.1 >>