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 D987DC43334 for ; Mon, 27 Jun 2022 16:45:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238570AbiF0Qpu (ORCPT ); Mon, 27 Jun 2022 12:45:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42986 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234113AbiF0Qps (ORCPT ); Mon, 27 Jun 2022 12:45:48 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 3302CDFCD; Mon, 27 Jun 2022 09:45:47 -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 2FB0B1758; Mon, 27 Jun 2022 09:45:47 -0700 (PDT) Received: from [10.1.31.127] (e127744.cambridge.arm.com [10.1.31.127]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 35AE73F66F; Mon, 27 Jun 2022 09:45:45 -0700 (PDT) Subject: Re: [PATCH] perf test: Add test for branch stack sampling To: Ian Rogers Cc: linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, acme@kernel.org, Anshuman Khandual , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim References: <20220615130901.1151397-1-german.gomez@arm.com> <20220615130901.1151397-2-german.gomez@arm.com> From: German Gomez Message-ID: Date: Mon, 27 Jun 2022 17:45:29 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.14.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 27/06/2022 17:38, Ian Rogers wrote: > On Wed, Jun 15, 2022 at 6:09 AM German Gomez wrote: >> Add a self test for branch stack sampling, to check that we get the >> expected branch types, and filters behave as expected. >> >> Suggested-by: Anshuman Khandual >> Signed-off-by: German Gomez > Love tests, thanks! There are already shell tests that compile C code > but they do it by having the C code within the shell test, for > example: > https://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git/tree/tools/perf/tests/shell/pipe_test.sh?h=perf/core#n14 > Having it this way I thinks means the tests can run properly when > installed, as we don't install non-sh files: > https://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git/tree/tools/perf/Makefile.perf?h=perf/core#n1016 Ah! thanks for pointing this out, Ian. I've embedded C code within shell tests before, but I wasn't aware of the install issue. We'll take care of this, thanks for the review! > > Thanks, > Ian > >> --- >> tools/perf/tests/shell/lib/brstack/main.h | 16 +++++ >> tools/perf/tests/shell/lib/brstack/test.c | 24 +++++++ >> tools/perf/tests/shell/test_brstack.sh | 86 +++++++++++++++++++++++ >> 3 files changed, 126 insertions(+) >> create mode 100644 tools/perf/tests/shell/lib/brstack/main.h >> create mode 100644 tools/perf/tests/shell/lib/brstack/test.c >> create mode 100755 tools/perf/tests/shell/test_brstack.sh >> >> diff --git a/tools/perf/tests/shell/lib/brstack/main.h b/tools/perf/tests/shell/lib/brstack/main.h >> new file mode 100644 >> index 000000000..94d2665ec >> --- /dev/null >> +++ b/tools/perf/tests/shell/lib/brstack/main.h >> @@ -0,0 +1,16 @@ >> +// SPDX-License-Identifier: GPL-2.0 >> +#define BENCH_RUNS 99999 >> + >> +void bench(void); >> + >> +int main(void) >> +{ >> + int cnt = 0; >> + >> + while (1) { >> + if ((cnt++) > BENCH_RUNS) >> + break; >> + bench(); /* call */ >> + } /* branch (uncond) */ >> + return 0; >> +} >> diff --git a/tools/perf/tests/shell/lib/brstack/test.c b/tools/perf/tests/shell/lib/brstack/test.c >> new file mode 100644 >> index 000000000..8a2308901 >> --- /dev/null >> +++ b/tools/perf/tests/shell/lib/brstack/test.c >> @@ -0,0 +1,24 @@ >> +// SPDX-License-Identifier: GPL-2.0 >> +#include "main.h" >> + >> +int cnt; >> + >> +void bar(void) >> +{ >> +} /* return */ >> + >> +void foo(void) >> +{ >> + bar(); /* call */ >> +} /* return */ >> + >> +void bench(void) >> +{ >> + void (*foo_ind)(void) = foo; >> + >> + if ((cnt++) % 3) /* branch (cond) */ >> + foo(); /* call */ >> + >> + bar(); /* call */ >> + foo_ind(); /* call (ind) */ >> +} >> diff --git a/tools/perf/tests/shell/test_brstack.sh b/tools/perf/tests/shell/test_brstack.sh >> new file mode 100755 >> index 000000000..2b1a1b20a >> --- /dev/null >> +++ b/tools/perf/tests/shell/test_brstack.sh >> @@ -0,0 +1,86 @@ >> +#!/bin/sh >> +# Check branch stack sampling >> + >> +# SPDX-License-Identifier: GPL-2.0 >> +# German Gomez , 2022 >> + >> +set -e >> + >> +# we need a C compiler to build the test programs >> +# so bail if none is found >> +if ! [ -x "$(command -v cc)" ]; then >> + echo "failed: no compiler, install gcc" >> + exit 2 >> +fi >> + >> +# skip the test if the hardware doesn't support branch stack sampling >> +perf record -b -o- -- true > /dev/null || exit 2 >> + >> +TMPDIR=$(mktemp -d /tmp/__perf_test.program.XXXXX) >> + >> +cleanup() { >> + rm -rf $TMPDIR >> +} >> + >> +trap cleanup exit term int >> + >> +test_user_branches() { >> + echo >> + echo "Testing user branch stack sampling" >> + echo >> + >> + cc -fno-inline -g "$(dirname $0)/lib/brstack/test.c" -o $TMPDIR/a.out >> + >> + perf record -o $TMPDIR/perf.data -q --branch-filter any,save_type,u -- $TMPDIR/a.out >> + perf script -i $TMPDIR/perf.data --fields brstacksym | xargs -n1 > $TMPDIR/perf.script >> + >> + # example of branch entries: >> + # foo+0x14/bar+0x40/P/-/-/0/CALL >> + >> + set -x >> + egrep -m1 "^bench\+[^ ]*/foo\+[^ ]*/IND_CALL$" $TMPDIR/perf.script >> + egrep -m1 "^foo\+[^ ]*/bar\+[^ ]*/CALL$" $TMPDIR/perf.script >> + egrep -m1 "^bench\+[^ ]*/foo\+[^ ]*/CALL$" $TMPDIR/perf.script >> + egrep -m1 "^bench\+[^ ]*/bar\+[^ ]*/CALL$" $TMPDIR/perf.script >> + egrep -m1 "^bar\+[^ ]*/foo\+[^ ]*/RET$" $TMPDIR/perf.script >> + egrep -m1 "^foo\+[^ ]*/bench\+[^ ]*/RET$" $TMPDIR/perf.script >> + egrep -m1 "^bench\+[^ ]*/bench\+[^ ]*/COND$" $TMPDIR/perf.script >> + egrep -m1 "^main\+[^ ]*/main\+[^ ]*/UNCOND$" $TMPDIR/perf.script >> + set +x >> + >> + # some branch types are still not being tested: >> + # IND COND_CALL COND_RET SYSCALL SYSRET IRQ SERROR NO_TX >> +} >> + >> +test_filter() { >> + local filter=$1 >> + local expect=$2 >> + >> + echo >> + echo "Testing branch stack filtering permutation ($filter,$expect)" >> + echo >> + >> + cc -fno-inline -g "$(dirname $0)/lib/brstack/test.c" -o $TMPDIR/a.out >> + >> + perf record -o $TMPDIR/perf.data -q --branch-filter $filter,save_type,u -- $TMPDIR/a.out >> + perf script -i $TMPDIR/perf.data --fields brstack | xargs -n1 > $TMPDIR/perf.script >> + >> + # fail if we find any branch type that doesn't match any of the expected ones >> + # also consider UNKNOWN branch types (-) >> + if egrep -vm1 "^[^ ]*/($expect|-|( *))$" $TMPDIR/perf.script; then >> + return 1 >> + fi >> +} >> + >> +test_user_branches >> + >> +# first argument is the argument passed to "--branch-stack ,save_type,u" >> +# second argument are the expected branch types for the given filter >> +test_filter "any_call" "CALL|IND_CALL|COND_CALL|SYSCALL|IRQ|FAULT_DATA|FAULT_INST" >> +test_filter "call" "CALL|SYSCALL" >> +test_filter "cond" "COND" >> +test_filter "any_ret" "RET|COND_RET|SYSRET|ERET" >> + >> +test_filter "call,cond" "CALL|SYSCALL|COND" >> +test_filter "any_call,cond" "CALL|IND_CALL|COND_CALL|IRQ|FAULT_DATA|FAULT_INST|SYSCALL|COND" >> +test_filter "cond,any_call,any_ret" "COND|CALL|IND_CALL|COND_CALL|SYSCALL|IRQ|FAULT_DATA|FAULT_INST|RET|COND_RET|SYSRET|ERET" >> -- >> 2.25.1 >>