Re: [PATCH] perf bench: flush stats when pipe it to a file or to tee

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Fri, Nov 12, 2021 at 11:53:12PM +0200, Sohaib Mohamed escreveu:
> The output of perf bench gets buffered when I pipe it to a file or to
> tee, in such a way that I can see it only at the end.

Good, now try with 'perf test' :-)

Applying,

- Arnaldo
 
> E.g.
> $ perf bench internals synthesize -t
> < output comes out fine after each test run >
> 
> $ perf bench internals synthesize -t | tee file.txt
> < output comes out only at the end of all tests >
> 
> See, also:
> $ perf bench mem all | tee file.txt
> $ perf bench sched all | tee file.txt
> $ perf bench internals all -t | tee file.txt
> $ perf bench internals all | tee file.txt
> 
> Suggested-by: Riccardo Mancini <rickyman7@gmail.com>
> Signed-off-by: Sohaib Mohamed <sohaib.amhmd@gmail.com>
> ---
>  tools/perf/bench/find-bit-bench.c | 1 +
>  tools/perf/bench/synthesize.c     | 2 ++
>  2 files changed, 3 insertions(+)
> 
> diff --git a/tools/perf/bench/find-bit-bench.c b/tools/perf/bench/find-bit-bench.c
> index 22b5cfe97023..39fb4184fbcb 100644
> --- a/tools/perf/bench/find-bit-bench.c
> +++ b/tools/perf/bench/find-bit-bench.c
> @@ -113,6 +113,7 @@ static int do_for_each_set_bit(unsigned int num_bits)
> 
>  		if (use_of_val == accumulator)  /* Try to avoid compiler tricks. */
>  			printf("\n");
> +		fflush(stdout);
>  	}
>  	bitmap_free(to_test);
>  	return 0;
> diff --git a/tools/perf/bench/synthesize.c b/tools/perf/bench/synthesize.c
> index 7401ebbac100..d21d311df61b 100644
> --- a/tools/perf/bench/synthesize.c
> +++ b/tools/perf/bench/synthesize.c
> @@ -92,6 +92,7 @@ static int do_run_single_threaded(struct perf_session *session,
>  		update_stats(&event_stats, atomic_read(&event_count));
>  	}
> 
> +	fflush(stdout);
>  	time_average = avg_stats(&time_stats);
>  	time_stddev = stddev_stats(&time_stats);
>  	printf("  Average %ssynthesis took: %.3f usec (+- %.3f usec)\n",
> @@ -186,6 +187,7 @@ static int do_run_multi_threaded(struct target *target,
>  		perf_session__delete(session);
>  	}
> 
> +	fflush(stdout);
>  	time_average = avg_stats(&time_stats);
>  	time_stddev = stddev_stats(&time_stats);
>  	printf("    Average synthesis took: %.3f usec (+- %.3f usec)\n",
> --
> 2.25.1

-- 

- Arnaldo