Em Mon, Jan 29, 2018 at 10:25:23AM +0100, ufo19890607 escreveu: > From: yuzhoujian <[email protected]> > > Introduce a new option to print counts after N milliseconds
This doesn't just print counts after N ms, it _stops_ the workload after that time _and_ prints the counts, right? Can you please send a followup patch fixing the description and documentation? I've applied this already, but clarifying what this option does is in demand. - Arnaldo > and update perf-stat documentation accordingly. > > Show below is the output of the new option for perf stat. > > $ perf stat --time 2000 -e cycles -a > Performance counter stats for 'system wide': > > 157,260,423 cycles > > 2.003060766 seconds time elapsed > > We can print the count deltas after N milliseconds with this new > introduced option. This option is not supported with "-I" option. > In addition, according to Kangliang's patch(19afd10410957), the > monitoring overhead for system-wide core event could be very high > if the interval-print parameter was below 100ms, and the limitation > value is 10ms. So the same warning will be displayed when the time > is set between 10ms to 100ms, and the minimal time is limited to > 10ms. Users can make a decision according to their spcific cases. > > Changes since v3: > - none. > > Changes since v2: > - modify the time check in __run_perf_stat func to keep some consistency > with the workload case. > - add the warning when the time is set between 10ms to 100ms. > - add the pr_err when the time is set below 10ms. > > Changes since v1: > - none. > > Signed-off-by: yuzhoujian <[email protected]> > --- > tools/perf/Documentation/perf-stat.txt | 5 +++++ > tools/perf/builtin-stat.c | 33 +++++++++++++++++++++++++++++++-- > tools/perf/util/stat.h | 1 + > 3 files changed, 37 insertions(+), 2 deletions(-) > > diff --git a/tools/perf/Documentation/perf-stat.txt > b/tools/perf/Documentation/perf-stat.txt > index 47a21645f60c..c822f374c99a 100644 > --- a/tools/perf/Documentation/perf-stat.txt > +++ b/tools/perf/Documentation/perf-stat.txt > @@ -151,6 +151,11 @@ Print count deltas for fixed number of times. > This option should be used together with "-I" option. > example: 'perf stat -I 1000 --interval-count 2 -e cycles -a' > > +--time msecs:: > +Print count deltas after N milliseconds (minimum: 10 ms). > +This option is not supported with "-I" option. > + example: 'perf stat --time 2000 -e cycles -a' > + > --metric-only:: > Only print computed metrics. Print them in a single line. > Don't show any raw values. Not supported with --per-thread. > diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c > index 7d1d7613bf56..582db3897374 100644 > --- a/tools/perf/builtin-stat.c > +++ b/tools/perf/builtin-stat.c > @@ -573,6 +573,7 @@ static int __run_perf_stat(int argc, const char **argv) > { > int interval = stat_config.interval; > int times = stat_config.times; > + int time = stat_config.time; > char msg[BUFSIZ]; > unsigned long long t0, t1; > struct perf_evsel *counter; > @@ -586,6 +587,9 @@ static int __run_perf_stat(int argc, const char **argv) > if (interval) { > ts.tv_sec = interval / USEC_PER_MSEC; > ts.tv_nsec = (interval % USEC_PER_MSEC) * NSEC_PER_MSEC; > + } else if (time) { > + ts.tv_sec = time / USEC_PER_MSEC; > + ts.tv_nsec = (time % USEC_PER_MSEC) * NSEC_PER_MSEC; > } else { > ts.tv_sec = 1; > ts.tv_nsec = 0; > @@ -698,9 +702,11 @@ static int __run_perf_stat(int argc, const char **argv) > perf_evlist__start_workload(evsel_list); > enable_counters(); > > - if (interval) { > + if (interval || time) { > while (!waitpid(child_pid, &status, WNOHANG)) { > nanosleep(&ts, NULL); > + if (time) > + break; > process_interval(); > if (interval_count && !(--times)) > break; > @@ -720,6 +726,8 @@ static int __run_perf_stat(int argc, const char **argv) > enable_counters(); > while (!done) { > nanosleep(&ts, NULL); > + if (time) > + break; > if (interval) { > process_interval(); > if (interval_count && !(--times)) > @@ -1900,6 +1908,8 @@ static const struct option stat_options[] = { > "print counts at regular interval in ms (>= 10)"), > OPT_INTEGER(0, "interval-count", &stat_config.times, > "print counts for fixed number of times"), > + OPT_UINTEGER(0, "time", &stat_config.time, > + "print counts after a period of time in ms (>= 10)"), > OPT_SET_UINT(0, "per-socket", &stat_config.aggr_mode, > "aggregate counts per processor socket", AGGR_SOCKET), > OPT_SET_UINT(0, "per-core", &stat_config.aggr_mode, > @@ -2697,7 +2707,7 @@ int cmd_stat(int argc, const char **argv) > int status = -EINVAL, run_idx; > const char *mode; > FILE *output = stderr; > - unsigned int interval; > + unsigned int interval, time; > const char * const stat_subcommands[] = { "record", "report" }; > > setlocale(LC_ALL, ""); > @@ -2728,6 +2738,7 @@ int cmd_stat(int argc, const char **argv) > return __cmd_report(argc, argv); > > interval = stat_config.interval; > + time = stat_config.time; > > /* > * For record command the -o is already taken care of. > @@ -2879,6 +2890,7 @@ int cmd_stat(int argc, const char **argv) > "The overhead percentage could be high in > some cases. " > "Please proceed with caution.\n"); > } > + > if (stat_config.times && interval) > interval_count = true; > else if (stat_config.times && !interval) { > @@ -2889,6 +2901,23 @@ int cmd_stat(int argc, const char **argv) > goto out; > } > > + if (time && time < 100) { > + if (time < 10) { > + pr_err("time must be >= 10ms.\n"); > + parse_options_usage(stat_usage, stat_options, "time", > 0); > + goto out; > + } else > + pr_warning("time < 100ms. " > + "The overhead percentage could be high in > some cases. " > + "Please proceed with caution.\n"); > + } > + if (time && interval) { > + pr_err("time option is not supported with interval-print.\n"); > + parse_options_usage(stat_usage, stat_options, "time", 0); > + parse_options_usage(stat_usage, stat_options, "I", 1); > + goto out; > + } > + > if (perf_evlist__alloc_stats(evsel_list, interval)) > goto out; > > diff --git a/tools/perf/util/stat.h b/tools/perf/util/stat.h > index 540fbb350e53..fc1ab635f7e0 100644 > --- a/tools/perf/util/stat.h > +++ b/tools/perf/util/stat.h > @@ -90,6 +90,7 @@ struct perf_stat_config { > bool scale; > FILE *output; > unsigned int interval; > + unsigned int time; > int times; > struct runtime_stat *stats; > int stats_num; > -- > 2.14.1
