perf stat: Refactor __run_perf_stat() common code

This extracts common code from the branches of the forks if-then-else.

enable_counters(), which was at the beginning of both branches of the
conditional, is now unconditional; evlist__start_workload() is extracted
to a different if, which enables making the common clocking code
unconditional.

Reviewed-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: Adrián Herrera Arcila <adrian.herrera@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/r/20220729161244.10522-1-adrian.herrera@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 3d22543fc305f1006ed27e960c25574638575b7a..b5ce07c5738a5b3fcf91b27e25912eaf973e21af 100644 (file)
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -967,18 +967,18 @@ try_again_reset:
                        return err;
        }
 
-       /*
-        * Enable counters and exec the command:
-        */
-       if (forks) {
-               err = enable_counters();
-               if (err)
-                       return -1;
+       err = enable_counters();
+       if (err)
+               return -1;
+
+       /* Exec the command, if any */
+       if (forks)
                evlist__start_workload(evsel_list);
 
-               t0 = rdclock();
-               clock_gettime(CLOCK_MONOTONIC, &ref_time);
+       t0 = rdclock();
+       clock_gettime(CLOCK_MONOTONIC, &ref_time);
 
+       if (forks) {
                if (interval || timeout || evlist__ctlfd_initialized(evsel_list))
                        status = dispatch_events(forks, timeout, interval, &times);
                if (child_pid != -1) {
@@ -996,13 +996,6 @@ try_again_reset:
                if (WIFSIGNALED(status))
                        psignal(WTERMSIG(status), argv[0]);
        } else {
-               err = enable_counters();
-               if (err)
-                       return -1;
-
-               t0 = rdclock();
-               clock_gettime(CLOCK_MONOTONIC, &ref_time);
-
                status = dispatch_events(forks, timeout, interval, &times);
        }