[PATCH v5 1/2] perf script: Fix perf script -F +metric

[Andi Kleen <ak@linux.intel.com>]

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
v3: Work around bogus warning
v4: Set up aggr map only for metrics case to keep perf stat record
working
---
 tools/perf/builtin-script.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index c16224b1fef3..33b5c7af5071 100644
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -2127,23 +2127,29 @@ static void perf_sample__fprint_metric(struct perf_script *script,
 	};
 	struct evsel *ev2;
 	u64 val;
+	struct cpu_aggr_map *map;
 
 	if (!evsel->stats)
 		evlist__alloc_stats(&stat_config, script->session->evlist, /*alloc_raw=*/false);
 	if (evsel_script(leader)->gnum++ == 0)
 		perf_stat__reset_shadow_stats();
 	val = sample->period * evsel->scale;
+	map = stat_config.aggr_map;
+	stat_config.aggr_map = &(struct cpu_aggr_map){ .nr = 1 };
+	/* 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);
 		}
 		evsel_script(leader)->gnum = 0;
 	}
+	stat_config.aggr_map = map;
 }
 
 static bool show_event(struct perf_sample *sample,
-- 
2.45.2