perf stat: Refactor __run_perf_stat() common code

[ Upstream commit bb8bc52e75785af94b9ba079277547d50d018a52 ]

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>
Stable-dep-of: c587e77e100f ("perf stat: Do not delay the workload with --delay")
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index abf88a1..2602c75 100644 (file)
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -953,18 +953,18 @@ 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) {
@@ -982,13 +982,6 @@ 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);
        }