Messages in this thread | | | From | Jiri Olsa <> | Date | Mon, 11 Jul 2022 22:56:31 +0200 | Subject | Re: [PATCH v2 1/1] perf test: Add test for branch stack sampling |
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On Tue, Jul 05, 2022 at 04:05:11PM +0100, 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 <anshuman.khandual@arm.com> > Signed-off-by: German Gomez <german.gomez@arm.com>
Tested-by: Jiri Olsa <jolsa@kernel.org>
thanks, jirka
> --- > tools/perf/tests/shell/test_brstack.sh | 114 +++++++++++++++++++++++++ > 1 file changed, 114 insertions(+) > create mode 100755 tools/perf/tests/shell/test_brstack.sh > > diff --git a/tools/perf/tests/shell/test_brstack.sh b/tools/perf/tests/shell/test_brstack.sh > new file mode 100755 > index 000000000..5f6f40a77 > --- /dev/null > +++ b/tools/perf/tests/shell/test_brstack.sh > @@ -0,0 +1,114 @@ > +#!/bin/sh > +# Check branch stack sampling > + > +# SPDX-License-Identifier: GPL-2.0 > +# German Gomez <german.gomez@arm.com>, 2022 > + > +# we need a C compiler to build the test programs > +# so bail if none is found > +if ! [ -x "$(command -v cc)" ]; then > + echo "failed: no compiler, install gcc" > + exit 2 > +fi > + > +# skip the test if the hardware doesn't support branch stack sampling > +perf record -b -o- -e dummy -B true > /dev/null 2>&1 || exit 2 > + > +TMPDIR=$(mktemp -d /tmp/__perf_test.program.XXXXX) > + > +cleanup() { > + rm -rf $TMPDIR > +} > + > +trap cleanup exit term int > + > +gen_test_program() { > + # generate test program > + cat << EOF > $1 > +#define BENCH_RUNS 999999 > +int cnt; > +void bar(void) { > +} /* return */ > +void foo(void) { > + bar(); /* call */ > +} /* return */ > +void bench(void) { > + void (*foo_ind)(void) = foo; > + if ((cnt++) % 3) /* branch (cond) */ > + foo(); /* call */ > + bar(); /* call */ > + foo_ind(); /* call (ind) */ > +} > +int main(void) > +{ > + int cnt = 0; > + while (1) { > + if ((cnt++) > BENCH_RUNS) > + break; > + bench(); /* call */ > + } /* branch (uncond) */ > + return 0; > +} > +EOF > +} > + > +test_user_branches() { > + echo "Testing user branch stack sampling" > + > + gen_test_program "$TEMPDIR/program.c" > + cc -fno-inline -g "$TEMPDIR/program.c" -o $TMPDIR/a.out > + > + perf record -o $TMPDIR/perf.data --branch-filter any,save_type,u -- $TMPDIR/a.out > /dev/null 2>&1 > + 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 > +} > + > +# first argument <arg0> is the argument passed to "--branch-stack <arg0>,save_type,u" > +# second argument are the expected branch types for the given filter > +test_filter() { > + local filter=$1 > + local expect=$2 > + > + echo "Testing branch stack filtering permutation ($filter,$expect)" > + > + gen_test_program "$TEMPDIR/program.c" > + cc -fno-inline -g "$TEMPDIR/program.c" -o $TMPDIR/a.out > + > + perf record -o $TMPDIR/perf.data --branch-filter $filter,save_type,u -- $TMPDIR/a.out > /dev/null 2>&1 > + 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 > +} > + > +set -e > + > +test_user_branches > + > +test_filter "any_call" "CALL|IND_CALL|COND_CALL|SYSCALL|IRQ" > +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|SYSCALL|COND" > +test_filter "cond,any_call,any_ret" "COND|CALL|IND_CALL|COND_CALL|SYSCALL|IRQ|RET|COND_RET|SYSRET|ERET" > -- > 2.25.1 >
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