perf stat: Add support to print counts for fixed times

Introduce a new option to print counts for fixed number of times and
update 'perf stat' documentation accordingly.

Show below is the output of the new option for perf stat.

  $ perf stat -I 1000 --interval-count 2 -e cycles -a
  #           time             counts unit events
           1.002827089         93,884,870      cycles
           2.004231506         56,573,446      cycles

We can just print the counts for several times with this newly
introduced option. The usage of it is a little like 'vmstat', and it
should be used together with "-I" option.

  $ vmstat -n 1 2
  procs ---------memory-------------- --swap- ----io-- -system-- ------cpu---
   r  b swpd   free   buff   cache    si   so  bi   bo  in   cs us sy id wa st
   0  0    0 78270544 547484 51732076  0   0   0   20    1    1  1  0 99  0 0
   0  0    0 78270512 547484 51732080  0   0   0   16  477 1555  0  0 100 0 0

Changes since v3:
- merge interval_count check and times check to one line.
- fix the wrong indent in stat.h
- use stat_config.times instead of 'times' in cmd_stat function.

Changes since v2:
- none.

Changes since v1:
- change the name of the new option "times-print" to "interval-count".
- keep the new option interval specifically.

Signed-off-by: yuzhoujian <yuzhoujian@didichuxing.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1517217923-8302-2-git-send-email-ufo19890607@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/Documentation/perf-stat.txt b/tools/perf/Documentation/perf-stat.txt
index 823fce7674bb133e2bfd6a67e42c757e3f930db4..47a21645f60cffcb8e5c16ea849cd899d66fb9f8 100644 (file)
--- a/tools/perf/Documentation/perf-stat.txt
+++ b/tools/perf/Documentation/perf-stat.txt
@@ -146,6 +146,11 @@ Print count deltas every N milliseconds (minimum: 10ms)
 The overhead percentage could be high in some cases, for instance with small, sub 100ms intervals.  Use with caution.
        example: 'perf stat -I 1000 -e cycles -a sleep 5'
 
+--interval-count times::
+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'
+
 --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 98bf9d32f2222247bf2b39d98dab62d9cafe1770..7d1d7613bf568c088a7c28c607f88f730fde6a3f 100644 (file)
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -168,6 +168,7 @@ static struct timespec              ref_time;
 static struct cpu_map          *aggr_map;
 static aggr_get_id_t           aggr_get_id;
 static bool                    append_file;
+static bool                    interval_count;
 static const char              *output_name;
 static int                     output_fd;
 static int                     print_free_counters_hint;
@@ -571,6 +572,7 @@ static struct perf_evsel *perf_evsel__reset_weak_group(struct perf_evsel *evsel)
 static int __run_perf_stat(int argc, const char **argv)
 {
        int interval = stat_config.interval;
+       int times = stat_config.times;
        char msg[BUFSIZ];
        unsigned long long t0, t1;
        struct perf_evsel *counter;
@@ -700,6 +702,8 @@ try_again:
                        while (!waitpid(child_pid, &status, WNOHANG)) {
                                nanosleep(&ts, NULL);
                                process_interval();
+                               if (interval_count && !(--times))
+                                       break;
                        }
                }
                waitpid(child_pid, &status, 0);
@@ -716,8 +720,11 @@ try_again:
                enable_counters();
                while (!done) {
                        nanosleep(&ts, NULL);
-                       if (interval)
+                       if (interval) {
                                process_interval();
+                               if (interval_count && !(--times))
+                                       break;
+                       }
                }
        }
 
@@ -1891,6 +1898,8 @@ static const struct option stat_options[] = {
                        "command to run after to the measured command"),
        OPT_UINTEGER('I', "interval-print", &stat_config.interval,
                    "print counts at regular interval in ms (>= 10)"),
+       OPT_INTEGER(0, "interval-count", &stat_config.times,
+                   "print counts for fixed number of times"),
        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,
@@ -2870,6 +2879,15 @@ 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) {
+               pr_err("interval-count option should be used together with "
+                               "interval-print.\n");
+               parse_options_usage(stat_usage, stat_options, "interval-count", 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 dbc6f7134f61533bf2ea83dc7e293a90eec43c69..540fbb350e53e4fc56d4bc6f066d573807f364d3 100644 (file)
--- 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;
+       int             times;
        struct runtime_stat *stats;
        int             stats_num;
 };