diff options
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/perf/Documentation/perf-stat.txt | 5 | ||||
| -rw-r--r-- | tools/perf/builtin-stat.c | 22 |
2 files changed, 26 insertions, 1 deletions
diff --git a/tools/perf/Documentation/perf-stat.txt b/tools/perf/Documentation/perf-stat.txt index 2fe87fb..73c9759 100644 --- a/tools/perf/Documentation/perf-stat.txt +++ b/tools/perf/Documentation/perf-stat.txt @@ -132,6 +132,11 @@ is a useful mode to detect imbalance between physical cores. To enable this mod use --per-core in addition to -a. (system-wide). The output includes the core number and the number of online logical processors on that physical processor. +-D msecs:: +--initial-delay msecs:: +After starting the program, wait msecs before measuring. This is useful to +filter out the startup phase of the program, which is often very different. + EXAMPLES -------- diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c index 352fbd7..2e637e4 100644 --- a/tools/perf/builtin-stat.c +++ b/tools/perf/builtin-stat.c @@ -100,6 +100,7 @@ static const char *pre_cmd = NULL; static const char *post_cmd = NULL; static bool sync_run = false; static unsigned int interval = 0; +static unsigned int initial_delay = 0; static bool forever = false; static struct timespec ref_time; static struct cpu_map *aggr_map; @@ -254,7 +255,8 @@ static int create_perf_stat_counter(struct perf_evsel *evsel) if (!perf_target__has_task(&target) && perf_evsel__is_group_leader(evsel)) { attr->disabled = 1; - attr->enable_on_exec = 1; + if (!initial_delay) + attr->enable_on_exec = 1; } return perf_evsel__open_per_thread(evsel, evsel_list->threads); @@ -416,6 +418,20 @@ static void print_interval(void) } } +static void handle_initial_delay(void) +{ + struct perf_evsel *counter; + + if (initial_delay) { + const int ncpus = cpu_map__nr(evsel_list->cpus), + nthreads = thread_map__nr(evsel_list->threads); + + usleep(initial_delay * 1000); + list_for_each_entry(counter, &evsel_list->entries, node) + perf_evsel__enable(counter, ncpus, nthreads); + } +} + static int __run_perf_stat(int argc, const char **argv) { char msg[512]; @@ -486,6 +502,7 @@ static int __run_perf_stat(int argc, const char **argv) if (forks) { perf_evlist__start_workload(evsel_list); + handle_initial_delay(); if (interval) { while (!waitpid(child_pid, &status, WNOHANG)) { @@ -497,6 +514,7 @@ static int __run_perf_stat(int argc, const char **argv) if (WIFSIGNALED(status)) psignal(WTERMSIG(status), argv[0]); } else { + handle_initial_delay(); while (!done) { nanosleep(&ts, NULL); if (interval) @@ -1419,6 +1437,8 @@ int cmd_stat(int argc, const char **argv, const char *prefix __maybe_unused) "aggregate counts per processor socket", AGGR_SOCKET), OPT_SET_UINT(0, "per-core", &aggr_mode, "aggregate counts per physical processor core", AGGR_CORE), + OPT_UINTEGER('D', "delay", &initial_delay, + "ms to wait before starting measurement after program start"), OPT_END() }; const char * const stat_usage[] = { |