[PATCH] perf stat: Pass PERF_STAT_RUN environment variable for each run

Namhyung Kim
2014-07-17T08:21:30Z

When perf stat runs multiple times via -r option, it's sometimes
useful for a workload to know which run it executing. So pass new
PERF_STAT_RUN environment variable to the workload for each run
(starting from 1).

Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
tools/perf/builtin-stat.c | 8 +++++---
tools/perf/util/evlist.c | 10 +++++++++-
2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 65a151e36067..53b3c99be5b3 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -144,6 +144,8 @@ static struct timespec ref_time;
static struct cpu_map *aggr_map;
static int (*aggr_get_id)(struct cpu_map *m, int cpu);

+int stat_run;
+
static volatile int done = 0;

struct perf_stat {
@@ -1674,7 +1676,7 @@ int cmd_stat(int argc, const char **argv, const char *prefix __maybe_unused)
"perf stat [<options>] [<command>]",
NULL
};
- int status = -EINVAL, run_idx;
+ int status = -EINVAL;
const char *mode;

setlocale(LC_ALL, "");
@@ -1812,10 +1814,10 @@ int cmd_stat(int argc, const char **argv, const char *prefix __maybe_unused)
signal(SIGABRT, skip_signal);

status = 0;
- for (run_idx = 0; forever || run_idx < run_count; run_idx++) {
+ for (stat_run = 1; forever || stat_run <= run_count; stat_run++) {
if (run_count != 1 && verbose)
fprintf(output, "[ perf stat: executing run #%d ... ]\n",
- run_idx + 1);
+ stat_run);

status = run_perf_stat(argc, argv);
if (forever && status != -1) {
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 59ef2802fcf6..3bd86aeea99d 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -1031,6 +1031,7 @@ out_err:
return err;
}

+extern int stat_run;
int perf_evlist__prepare_workload(struct perf_evlist *evlist, struct target *target,
const char *argv[], bool pipe_output,
void (*exec_error)(int signo, siginfo_t *info, void *ucontext))
@@ -1055,6 +1056,8 @@ int perf_evlist__prepare_workload(struct perf_evlist *evlist, struct target *tar
}

if (!evlist->workload.pid) {
+ char buf[32];
+
if (pipe_output)
dup2(2, 1);

@@ -1075,7 +1078,12 @@ int perf_evlist__prepare_workload(struct perf_evlist *evlist, struct target *tar
if (read(go_pipe[0], &bf, 1) == -1)
perror("unable to read pipe");

- execvp(argv[0], (char **)argv);
+ if (stat_run) {
+ snprintf(buf, sizeof(buf), "%d", stat_run);
+ setenv("PERF_STAT_RUN", buf, 1);
+ }
+
+ execvpe(argv[0], (char **)argv, environ);

if (exec_error) {
union sigval val;
--
2.0.1