Messages in this thread |  | | Subject | Re: [PATCH 5/5] perf arm-spe: Snapshot mode test | From | James Clark <> | Date | Tue, 2 Nov 2021 15:37:10 +0000 |
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On 02/11/2021 14:07, James Clark wrote: > > > 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 <james.clark@arm.com> >>> Signed-off-by: German Gomez <german.gomez@arm.com> >>> --- >>> 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 <german.gomez@arm.com>, 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 <herbert@gondor.apana.org.au> > 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 <herbert@gondor.apana.org.au> > > > 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 >
Ok, it seems like I was relying on buggy dash behaviour for my original change. Even with this:
if [[ "$1" == "int" ]]; then kill -SIGINT $$ fi if [[ "$1" == "term" ]]; then kill -SIGTERM $$ fi
it still doesn't allow you to break out of running it in a while loop. This is only because of the exit code, rather than any kind of signal propagation. Actually it's possible to stop it with Ctrl-\ rather than Ctrl-C, and that doesn't require any extra handling in the script.
For that reason I'm happy to go with Leo's original suggestion when I first added this which was to not have any extra kill at all.
Another fix could be this, but I'm not too keen on it because I don't think any other tests behave like this:
[ "$1" = "int" ] || exit 1 [ "$1" = "term" ] || exit 1
>> >>> + 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 >>>
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