Commit d509d14f authored Dec 03, 2025 by Ian Rogers Committed by Namhyung Kim Dec 04, 2025

perf stat: Improve handling of termination by signal



When interrupting perf stat in repeat mode with a signal the signal is
passed to the child process but the repeat doesn't terminate:
```
$ perf stat -v --null --repeat 10 sleep 1
Control descriptor is not initialized
[ perf stat: executing run #1 ... ]
[ perf stat: executing run #2 ... ]
^Csleep: Interrupt
[ perf stat: executing run #3 ... ]
[ perf stat: executing run #4 ... ]
[ perf stat: executing run #5 ... ]
[ perf stat: executing run #6 ... ]
[ perf stat: executing run #7 ... ]
[ perf stat: executing run #8 ... ]
[ perf stat: executing run #9 ... ]
[ perf stat: executing run #10 ... ]

 Performance counter stats for 'sleep 1' (10 runs):

            0.9500 +- 0.0512 seconds time elapsed  ( +-  5.39% )

0.01user 0.02system 0:09.53elapsed 0%CPU (0avgtext+0avgdata 18940maxresident)k
29944inputs+0outputs (0major+2629minor)pagefaults 0swaps
```

Terminate the repeated run and give a reasonable exit value:
```
$ perf stat -v --null --repeat 10 sleep 1
Control descriptor is not initialized
[ perf stat: executing run #1 ... ]
[ perf stat: executing run #2 ... ]
[ perf stat: executing run #3 ... ]
^Csleep: Interrupt

 Performance counter stats for 'sleep 1' (10 runs):

             0.680 +- 0.321 seconds time elapsed  ( +- 47.16% )

Command exited with non-zero status 130
0.00user 0.01system 0:02.05elapsed 0%CPU (0avgtext+0avgdata 70688maxresident)k
0inputs+0outputs (0major+5002minor)pagefaults 0swaps
```

Note, this also changes the exit value for non-repeat runs when
interrupted by a signal.

Reported-by: Ingo Molnar <mingo@kernel.org>
Closes: https://lore.kernel.org/lkml/aS5wjmbAM9ka3M2g@gmail.com/


Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

parent 51235096

tools/perf/builtin-stat.c

+16 −5

Original line number	Diff line number	Diff line
		@@ -1007,10 +1007,20 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
		goto err_out;
		}

		if (WIFSIGNALED(status))
		if (WIFSIGNALED(status)) {
		/*
		* We want to indicate failure to stop a repeat run,
		* hence negative. We want the value to be the exit code
		* of perf, which for termination by a signal is 128
		* plus the signal number.
		*/
		err = 0 - (128 + WTERMSIG(status));
		psignal(WTERMSIG(status), argv[0]);
		} else {
		status = dispatch_events(forks, timeout, interval, &times);
		err = WEXITSTATUS(status);
		}
		} else {
		err = dispatch_events(forks, timeout, interval, &times);
		}

		disable_counters();
		@@ -1050,7 +1060,7 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
		if (!STAT_RECORD)
		evlist__close(evsel_list);

		return WEXITSTATUS(status);
		return err;

		err_out:
		if (forks)
		@@ -2969,7 +2979,7 @@ int cmd_stat(int argc, const char **argv)
		evlist__reset_prev_raw_counts(evsel_list);

		status = run_perf_stat(argc, argv, run_idx);
		if (status == -1)
		if (status < 0)
		break;

		if (forever && !interval) {
		@@ -3039,5 +3049,6 @@ int cmd_stat(int argc, const char **argv)

		evlist__close_control(stat_config.ctl_fd, stat_config.ctl_fd_ack, &stat_config.ctl_fd_close);

		return status;
		/* Only the low byte of status becomes the exit code. */
		return abs(status);
		}