[PATCH v2 1/2] perf script: Fix perf script -F +metric

[PATCH v2 1/2] perf script: Fix perf script -F +metric

[Andi Kleen]

This fixes a regression with perf script -F +metric originally caused by :

commit 37cc8ad77cf81f3ffd226856c367b0e15333a738
Author: Ian Rogers <irogers@google.com>
Date:   Sun Feb 19 01:28:46 2023 -0800

    perf metric: Directly use counts rather than saved_value

In the perf script environment the evsel wouldn't allocate an aggr
values array, which led to a -1 reference because the metric
evaluation would try to reference NULL - 1 (for aggr_idx)

Give the perf script evsels a single CPU aggr setup. That's
enough because the groups are always contiguous, so no need
to store more than one CPU's worth of values.

Before

% perf record -e '{cycles,instructions}:S' perf bench  mem memcpy
% perf script -F +metric
Segmentation fault (core dumped)

After:

% perf record -e '{cycles,instructions}:S' perf bench  mem memcpy
...
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.028 MB perf.data (90 samples) ]
% perf script -F +metric
       perf-exec 1847557 264658.180789:       3009       cycles:  ffffffff990a579a native_write_msr+0xa ([kernel.kallsyms])
       perf-exec 1847557 264658.180789:        382 instructions:  ffffffff990a579a native_write_msr+0xa ([kernel.kallsyms])
       perf-exec 1847557 264658.180789:         metric:    0.13  insn per cycle
...

Fixes: 37cc8ad77cf8 ("perf metric: Directly use counts rather ...")
Signed-off-by: Andi Kleen <ak@linux.intel.com>

--

v2: Reformat code
---
 tools/perf/builtin-script.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index c16224b1fef3..0aeff280fa55 100644
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -84,7 +84,9 @@ static bool			system_wide;
 static bool			print_flags;
 static const char		*cpu_list;
 static DECLARE_BITMAP(cpu_bitmap, MAX_NR_CPUS);
-static struct perf_stat_config	stat_config;
+static struct perf_stat_config	stat_config = {
+	.aggr_map = &(struct cpu_aggr_map){ .nr = 1 }
+};
 static int			max_blocks;
 static bool			native_arch;
 static struct dlfilter		*dlfilter;
@@ -2133,12 +2135,14 @@ static void perf_sample__fprint_metric(struct perf_script *script,
 	if (evsel_script(leader)->gnum++ == 0)
 		perf_stat__reset_shadow_stats();
 	val = sample->period * evsel->scale;
+	/* Always use CPU 0 storage because the groups are contiguous. */
+	evsel->stats->aggr[0].counts.val = val;
 	evsel_script(evsel)->val = val;
 	if (evsel_script(leader)->gnum == leader->core.nr_members) {
 		for_each_group_member (ev2, leader) {
 			perf_stat__print_shadow_stats(&stat_config, ev2,
 						      evsel_script(ev2)->val,
-						      sample->cpu,
+						      0,
 						      &ctx,
 						      NULL);
 		}
-- 
2.45.2

[PATCH v2 2/2] Add a test case for perf script -F +metric

[Andi Kleen]

Just a simple test

Signed-off-by: Andi Kleen <ak@linux.intel.com>

--

v2: Avoid bashisms. Use noploop
---
 tools/perf/tests/shell/script.sh | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/tools/perf/tests/shell/script.sh b/tools/perf/tests/shell/script.sh
index c1a603653662..de4b1dce55ad 100755
--- a/tools/perf/tests/shell/script.sh
+++ b/tools/perf/tests/shell/script.sh
@@ -7,6 +7,7 @@ set -e
 temp_dir=$(mktemp -d /tmp/perf-test-script.XXXXXXXXXX)
 
 perfdatafile="${temp_dir}/perf.data"
+scriptoutput="${temp_dir}/script"
 db_test="${temp_dir}/db_test.py"
 
 err=0
@@ -88,8 +89,21 @@ test_parallel_perf()
 	echo "parallel-perf test [Success]"
 }
 
+test_metric()
+{
+	echo "script metric test"
+	if ! perf list | grep -q cycles ; then return ; fi
+	if ! perf list | grep -q instructions ; then return ; fi
+	perf record -e '{cycles,instructions}' -o "${perfdatafile}" perf test -w noploop
+	perf script -i "${perfdatafile}" -F +metric  > $scriptoutput
+	test `grep -c metric $scriptoutput` -gt 5
+	grep metric $scriptoutput | head
+	echo "script metric test [Success]"
+}
+
 test_db
 test_parallel_perf
+test_metric
 
 cleanup
 
-- 
2.45.2

Re: [PATCH v2 1/2] perf script: Fix perf script -F +metric

[Namhyung Kim]

Hi Andi,

On Thu, Jun 27, 2024 at 05:04:54PM -0700, Andi Kleen wrote:
> This fixes a regression with perf script -F +metric originally caused by :
> 
> commit 37cc8ad77cf81f3ffd226856c367b0e15333a738
> Author: Ian Rogers <irogers@google.com>
> Date:   Sun Feb 19 01:28:46 2023 -0800
> 
>     perf metric: Directly use counts rather than saved_value
> 
> In the perf script environment the evsel wouldn't allocate an aggr
> values array, which led to a -1 reference because the metric
> evaluation would try to reference NULL - 1 (for aggr_idx)
> 
> Give the perf script evsels a single CPU aggr setup. That's
> enough because the groups are always contiguous, so no need
> to store more than one CPU's worth of values.
> 
> Before
> 
> % perf record -e '{cycles,instructions}:S' perf bench  mem memcpy
> % perf script -F +metric
> Segmentation fault (core dumped)
> 
> After:
> 
> % perf record -e '{cycles,instructions}:S' perf bench  mem memcpy
> ...
> [ perf record: Woken up 1 times to write data ]
> [ perf record: Captured and wrote 0.028 MB perf.data (90 samples) ]
> % perf script -F +metric
>        perf-exec 1847557 264658.180789:       3009       cycles:  ffffffff990a579a native_write_msr+0xa ([kernel.kallsyms])
>        perf-exec 1847557 264658.180789:        382 instructions:  ffffffff990a579a native_write_msr+0xa ([kernel.kallsyms])
>        perf-exec 1847557 264658.180789:         metric:    0.13  insn per cycle
> ...
> 
> Fixes: 37cc8ad77cf8 ("perf metric: Directly use counts rather ...")
> Signed-off-by: Andi Kleen <ak@linux.intel.com>
> 
> --

This should be "---" instead of "--".  Otherwise git or b4 is confused
and add tags under this section.

Thanks,
Namhyung

> 
> v2: Reformat code
> ---
>  tools/perf/builtin-script.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
> index c16224b1fef3..0aeff280fa55 100644
> --- a/tools/perf/builtin-script.c
> +++ b/tools/perf/builtin-script.c
> @@ -84,7 +84,9 @@ static bool			system_wide;
>  static bool			print_flags;
>  static const char		*cpu_list;
>  static DECLARE_BITMAP(cpu_bitmap, MAX_NR_CPUS);
> -static struct perf_stat_config	stat_config;
> +static struct perf_stat_config	stat_config = {
> +	.aggr_map = &(struct cpu_aggr_map){ .nr = 1 }
> +};
>  static int			max_blocks;
>  static bool			native_arch;
>  static struct dlfilter		*dlfilter;
> @@ -2133,12 +2135,14 @@ static void perf_sample__fprint_metric(struct perf_script *script,
>  	if (evsel_script(leader)->gnum++ == 0)
>  		perf_stat__reset_shadow_stats();
>  	val = sample->period * evsel->scale;
> +	/* Always use CPU 0 storage because the groups are contiguous. */
> +	evsel->stats->aggr[0].counts.val = val;
>  	evsel_script(evsel)->val = val;
>  	if (evsel_script(leader)->gnum == leader->core.nr_members) {
>  		for_each_group_member (ev2, leader) {
>  			perf_stat__print_shadow_stats(&stat_config, ev2,
>  						      evsel_script(ev2)->val,
> -						      sample->cpu,
> +						      0,
>  						      &ctx,
>  						      NULL);
>  		}
> -- 
> 2.45.2
> 

Re: [PATCH v2 2/2] Add a test case for perf script -F +metric

[Namhyung Kim]

On Thu, Jun 27, 2024 at 05:04:55PM -0700, Andi Kleen wrote:
> Just a simple test
> 
> Signed-off-by: Andi Kleen <ak@linux.intel.com>
> 
> --
> 
> v2: Avoid bashisms. Use noploop
> ---
>  tools/perf/tests/shell/script.sh | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
> 
> diff --git a/tools/perf/tests/shell/script.sh b/tools/perf/tests/shell/script.sh
> index c1a603653662..de4b1dce55ad 100755
> --- a/tools/perf/tests/shell/script.sh
> +++ b/tools/perf/tests/shell/script.sh
> @@ -7,6 +7,7 @@ set -e
>  temp_dir=$(mktemp -d /tmp/perf-test-script.XXXXXXXXXX)
>  
>  perfdatafile="${temp_dir}/perf.data"
> +scriptoutput="${temp_dir}/script"
>  db_test="${temp_dir}/db_test.py"
>  
>  err=0
> @@ -88,8 +89,21 @@ test_parallel_perf()
>  	echo "parallel-perf test [Success]"
>  }
>  
> +test_metric()
> +{
> +	echo "script metric test"
> +	if ! perf list | grep -q cycles ; then return ; fi
> +	if ! perf list | grep -q instructions ; then return ; fi
> +	perf record -e '{cycles,instructions}' -o "${perfdatafile}" perf test -w noploop
> +	perf script -i "${perfdatafile}" -F +metric  > $scriptoutput
> +	test `grep -c metric $scriptoutput` -gt 5

The shellcheck (now part of build process) doesn't like this.

  In tests/shell/script.sh line 99:
  	test `grep -c metric $scriptoutput` -gt 5
               ^----------------------------^ SC2046 (warning): Quote this to prevent word splitting.
  
  For more information:
    https://www.shellcheck.net/wiki/SC2046 -- Quote this to prevent word splitt...
  make[4]: *** [tests/Build:91: tests/shell/script.sh.shellcheck_log] Error 1
  make[3]: *** [linux/tools/build/Makefile.build:158: tests] Error 2
  make[2]: *** [Makefile.perf:750: perf-test-in.o] Error 2
  make[2]: *** Waiting for unfinished jobs....

Thanks,
Namhyung


> +	grep metric $scriptoutput | head
> +	echo "script metric test [Success]"
> +}
> +
>  test_db
>  test_parallel_perf
> +test_metric
>  
>  cleanup
>  
> -- 
> 2.45.2
>