Commit b77f8c36 authored Sep 25, 2024 by Levi Yun Committed by Namhyung Kim Sep 25, 2024

perf stat: Stop repeating when ref_perf_stat() returns -1



Exit when run_perf_stat() returns an error to avoid continuously
repeating the same error message. It's not expected that COUNTER_FATAL
or internal errors are recoverable so there's no point in retrying.

This fixes the following flood of error messages for permission issues,
for example when perf_event_paranoid==3:
  perf stat -r 1044 -- false

  Error:
  Access to performance monitoring and observability operations is limited.
  ...
  Error:
  Access to performance monitoring and observability operations is limited.
  ...
  (repeating for 1044 times).

Signed-off-by: Levi Yun <yeoreum.yun@arm.com>
Reviewed-by: James Clark <james.clark@linaro.org>
Cc: nd@arm.com
Cc: howardchu95@gmail.com
Link: https://lore.kernel.org/r/20240925132022.2650180-3-yeoreum.yun@arm.com


Signed-off-by: Namhyung Kim <namhyung@kernel.org>

parent e880a70f

tools/perf/builtin-stat.c

+12 −1

Original line number	Diff line number	Diff line
		@@ -968,6 +968,14 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
		return err;
		}

		/*
		* Returns -1 for fatal errors which signifies to not continue
		* when in repeat mode.
		*
		* Returns < -1 error codes when stat record is used. These
		* result in the stat information being displayed, but writing
		* to the file fails and is non fatal.
		*/
		static int run_perf_stat(int argc, const char **argv, int run_idx)
		{
		int ret;
		@@ -2899,7 +2907,10 @@ int cmd_stat(int argc, const char **argv)
		evlist__reset_prev_raw_counts(evsel_list);

		status = run_perf_stat(argc, argv, run_idx);
		if (forever && status != -1 && !interval) {
		if (status == -1)
		break;

		if (forever && !interval) {
		print_counters(NULL, argc, argv);
		perf_stat__reset_stats();
		}