From f0a29c9647ff8bbb424641f79bc1894e83dec218 Mon Sep 17 00:00:00 2001 From: Sohaib Mohamed Date: Fri, 19 Nov 2021 08:14:08 +0200 Subject: [PATCH] perf bench: Use unbuffered output when pipe/tee'ing to a file 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. 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 > This patch resolves this issue for 'bench' and 'test' subcommands. 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 Committer testing: It really gets staggered, i.e. outputs in bursts, when the buffer fills up and has to be drained to make up space for more output. Suggested-by: Riccardo Mancini Signed-off-by: Sohaib Mohamed Tested-by: Arnaldo Carvalho de Melo Acked-by: Jiri Olsa Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Fabian Hemmer Cc: Ian Rogers Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lore.kernel.org/lkml/20211119061409.78004-1-sohaib.amhmd@gmail.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-bench.c | 5 +++-- tools/perf/tests/builtin-test.c | 3 +++ 2 files changed, 6 insertions(+), 2 deletions(-) diff --git a/tools/perf/builtin-bench.c b/tools/perf/builtin-bench.c index d0895162c2ba..d291f3a8af5f 100644 --- a/tools/perf/builtin-bench.c +++ b/tools/perf/builtin-bench.c @@ -226,7 +226,6 @@ static void run_collection(struct collection *coll) if (!bench->fn) break; printf("# Running %s/%s benchmark...\n", coll->name, bench->name); - fflush(stdout); argv[1] = bench->name; run_bench(coll->name, bench->name, bench->fn, 1, argv); @@ -247,6 +246,9 @@ int cmd_bench(int argc, const char **argv) struct collection *coll; int ret = 0; + /* Unbuffered output */ + setvbuf(stdout, NULL, _IONBF, 0); + if (argc < 2) { /* No collection specified. */ print_usage(); @@ -300,7 +302,6 @@ int cmd_bench(int argc, const char **argv) if (bench_format == BENCH_FORMAT_DEFAULT) printf("# Running '%s/%s' benchmark:\n", coll->name, bench->name); - fflush(stdout); ret = run_bench(coll->name, bench->name, bench->fn, argc-1, argv+1); goto end; } diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c index f1e6d2a3a578..1fb9f2a11d63 100644 --- a/tools/perf/tests/builtin-test.c +++ b/tools/perf/tests/builtin-test.c @@ -607,6 +607,9 @@ int cmd_test(int argc, const char **argv) if (ret < 0) return ret; + /* Unbuffered output */ + setvbuf(stdout, NULL, _IONBF, 0); + argc = parse_options_subcommand(argc, argv, test_options, test_subcommands, test_usage, 0); if (argc >= 1 && !strcmp(argv[0], "list")) return perf_test__list(argc - 1, argv + 1); -- 2.50.1