Re: [PATCH 3/8] perf test: Use a test program in perf record tests

[Ian Rogers]

On Thu, Oct 20, 2022 at 10:26 AM Namhyung Kim <namhyung@xxxxxxxxxx> wrote:
>
> If the system has cc it could build a test program with two threads
> and then use it for more detailed testing.  Also it accepts an option
> to run a thread forever to ensure multi-thread runs.
>
> If cc is not found, it falls back to use the default value 'true'.
>
> Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>

Acked-by: Ian Rogers <irogers@xxxxxxxxxx>

I wonder if these utilities should just be built into perf to avoid
the cc dependency. Perhaps we can have a hidden option built into perf
test.

Thanks,
Ian

> ---
>  tools/perf/tests/shell/record.sh | 64 ++++++++++++++++++++++++++++++--
>  1 file changed, 60 insertions(+), 4 deletions(-)
>
> diff --git a/tools/perf/tests/shell/record.sh b/tools/perf/tests/shell/record.sh
> index 464071462809..952981481239 100755
> --- a/tools/perf/tests/shell/record.sh
> +++ b/tools/perf/tests/shell/record.sh
> @@ -6,10 +6,17 @@ set -e
>
>  err=0
>  perfdata=$(mktemp /tmp/__perf_test.perf.data.XXXXX)
> +testprog=$(mktemp /tmp/__perf_test.prog.XXXXXX)
> +testsym="test_loop"
>
>  cleanup() {
>    rm -f "${perfdata}"
>    rm -f "${perfdata}".old
> +
> +  if [ "${testprog}" != "true" ]; then
> +    rm -f "${testprog}"
> +  fi
> +
>    trap - EXIT TERM INT
>  }
>
> @@ -19,9 +26,56 @@ trap_cleanup() {
>  }
>  trap trap_cleanup EXIT TERM INT
>
> +build_test_program() {
> +  if ! [ -x "$(command -v cc)" ]; then
> +    # No CC found. Fall back to 'true'
> +    testprog=true
> +    testsym=true
> +    return
> +  fi
> +
> +  echo "Build a test program"
> +  cat <<EOF | cc -o ${testprog} -xc - -pthread
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <pthread.h>
> +
> +void test_loop(void) {
> +  volatile int count = 1000000;
> +
> +  while (count--)
> +    continue;
> +}
> +
> +void *thfunc(void *arg) {
> +  int forever = *(int *)arg;
> +
> +  do {
> +    test_loop();
> +  } while (forever);
> +
> +  return NULL;
> +}
> +
> +int main(int argc, char *argv[]) {
> +  pthread_t th;
> +  int forever = 0;
> +
> +  if (argc > 1)
> +    forever = atoi(argv[1]);
> +
> +  pthread_create(&th, NULL, thfunc, &forever);
> +  test_loop();
> +  pthread_join(th, NULL);
> +
> +  return 0;
> +}
> +EOF
> +}
> +
>  test_per_thread() {
>    echo "Basic --per-thread mode test"
> -  if ! perf record -o /dev/null --quiet true 2> /dev/null
> +  if ! perf record -o /dev/null --quiet ${testprog} 2> /dev/null
>    then
>      echo "Per-thread record [Skipped event not supported]"
>      if [ $err -ne 1 ]
> @@ -30,13 +84,13 @@ test_per_thread() {
>      fi
>      return
>    fi
> -  if ! perf record --per-thread -o "${perfdata}" true 2> /dev/null
> +  if ! perf record --per-thread -o "${perfdata}" ${testprog} 2> /dev/null
>    then
>      echo "Per-thread record [Failed record]"
>      err=1
>      return
>    fi
> -  if ! perf report -i "${perfdata}" -q | grep -q true
> +  if ! perf report -i "${perfdata}" -q | grep -q "${testsym}"
>    then
>      echo "Per-thread record [Failed missing output]"
>      err=1
> @@ -62,7 +116,7 @@ test_register_capture() {
>      return
>    fi
>    if ! perf record -o - --intr-regs=di,r8,dx,cx -e br_inst_retired.near_call:p \
> -    -c 1000 --per-thread true 2> /dev/null \
> +    -c 1000 --per-thread ${testprog} 2> /dev/null \
>      | perf script -F ip,sym,iregs -i - 2> /dev/null \
>      | grep -q "DI:"
>    then
> @@ -73,6 +127,8 @@ test_register_capture() {
>    echo "Register capture test [Success]"
>  }
>
> +build_test_program
> +
>  test_per_thread
>  test_register_capture
>
> --
> 2.38.0.135.g90850a2211-goog
>