perf sched: Account for lost events, increase default buffering

Output such lost event and state machine weirdness stats:

   TOTAL:                |  14974.910 ms |    46384 |
  ---------------------------------------------------
   INFO: 8.865% lost events (19132 out of 215819, in 8 chunks)
   INFO: 0.198% state machine bugs (49 out of 24708) (due to lost events?)

And increase buffering to -m 1024 (4 MB) by default. Since we
use output multiplexing that kind of space is needed.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

2 files changed, 42 insertions, 20 deletions

diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
index adcb563ec4d2..1f0f9be34faa 100644
--- a/tools/perf/builtin-sched.c
+++ b/tools/perf/builtin-sched.c
@@ -117,7 +117,11 @@ static u64			run_avg;
 
 static unsigned long            replay_repeat = 10;
 static unsigned long            nr_timestamps;
-static unsigned long            unordered_timestamps;
+static unsigned long            nr_unordered_timestamps;
+static unsigned long            nr_state_machine_bugs;
+static unsigned long            nr_events;
+static unsigned long            nr_lost_chunks;
+static unsigned long            nr_lost_events;
 
 #define TASK_STATE_TO_CHAR_STR "RSDTtZX"
 
@@ -668,14 +672,14 @@ process_comm_event(event_t *event, unsigned long offset, unsigned long head)
 
         thread = threads__findnew(event->comm.pid, &threads, &last_match);
 
-        dump_printf("%p [%p]: PERF_EVENT_COMM: %s:%d\n",
+        dump_printf("%p [%p]: perf_event_comm: %s:%d\n",
                 (void *)(offset + head),
                 (void *)(long)(event->header.size),
                 event->comm.comm, event->comm.pid);
 
         if (thread == NULL ||
             thread__set_comm(thread, event->comm.comm)) {
-                dump_printf("problem processing PERF_EVENT_COMM, skipping event.\n");
+                dump_printf("problem processing perf_event_comm, skipping event.\n");
                 return -1;
         }
         total_comm++;
@@ -1168,14 +1172,12 @@ latency_wakeup_event(struct trace_wakeup_event *wakeup_event,
 
         atom = list_entry(atoms->work_list.prev, struct work_atom, list);
 
-        if (atom->state != THREAD_SLEEPING) {
-                printf("boo2\n");
-                return;
-        }
+        if (atom->state != THREAD_SLEEPING)
+                nr_state_machine_bugs++;
 
         nr_timestamps++;
         if (atom->sched_out_time > timestamp) {
-                unordered_timestamps++;
+                nr_unordered_timestamps++;
                 return;
         }
 
@@ -1214,7 +1216,7 @@ static void output_lat_thread(struct work_atoms *work_list)
 
         avg = work_list->total_lat / work_list->nb_atoms;
 
-        printf("|%9.3f ms |%9llu | avg:%9.3f ms | max:%9.3f ms |\n",
+        printf("|%11.3f ms |%9llu | avg:%9.3f ms | max:%9.3f ms |\n",
               (double)work_list->total_runtime / 1e6,
                  work_list->nb_atoms, (double)avg / 1e6,
                  (double)work_list->max_lat / 1e6);
@@ -1359,9 +1361,9 @@ static void __cmd_lat(void)
         read_events();
         sort_lat();
 
-        printf("\n ---------------------------------------------------------------------------------------\n");
-        printf("  Task                  |  Runtime ms | Switches | Average delay ms | Maximum delay ms |\n");
-        printf(" ---------------------------------------------------------------------------------------\n");
+        printf("\n -----------------------------------------------------------------------------------------\n");
+        printf("  Task                  |   Runtime ms  | Switches | Average delay ms | Maximum delay ms |\n");
+        printf(" -----------------------------------------------------------------------------------------\n");
 
         next = rb_first(&sorted_atom_root);
 
@@ -1373,18 +1375,32 @@ static void __cmd_lat(void)
                 next = rb_next(next);
         }
 
-        printf(" ---------------------------------------------------------------------------------------\n");
-        printf("  TOTAL:                |%9.3f ms |%9Ld |",
+        printf(" -----------------------------------------------------------------------------------------\n");
+        printf("  TOTAL:                |%11.3f ms |%9Ld |\n",
                 (double)all_runtime/1e6, all_count);
 
-        if (unordered_timestamps && nr_timestamps) {
-                printf(" INFO: %.2f%% unordered events.\n",
-                        (double)unordered_timestamps/(double)nr_timestamps*100.0);
+        printf(" ---------------------------------------------------\n");
+        if (nr_unordered_timestamps && nr_timestamps) {
+                printf("  INFO: %.3f%% unordered timestamps (%ld out of %ld)\n",
+                        (double)nr_unordered_timestamps/(double)nr_timestamps*100.0,
+                        nr_unordered_timestamps, nr_timestamps);
         } else {
+        }
+        if (nr_lost_events && nr_events) {
+                printf("  INFO: %.3f%% lost events (%ld out of %ld, in %ld chunks)\n",
+                        (double)nr_lost_events/(double)nr_events*100.0,
+                        nr_lost_events, nr_events, nr_lost_chunks);
+        }
+        if (nr_state_machine_bugs && nr_timestamps) {
+                printf("  INFO: %.3f%% state machine bugs (%ld out of %ld)",
+                        (double)nr_state_machine_bugs/(double)nr_timestamps*100.0,
+                        nr_state_machine_bugs, nr_timestamps);
+                if (nr_lost_events)
+                        printf(" (due to lost events?)");
                 printf("\n");
         }
+        printf("\n");
 
-        printf(" -------------------------------------------------\n\n");
 }
 
 static struct trace_sched_handler *trace_handler;
@@ -1585,8 +1601,13 @@ process_event(event_t *event, unsigned long offset, unsigned long head)
 {
         trace_event(event);
 
+        nr_events++;
         switch (event->header.type) {
-        case PERF_EVENT_MMAP ... PERF_EVENT_LOST:
+        case PERF_EVENT_MMAP:
+                return 0;
+        case PERF_EVENT_LOST:
+                nr_lost_chunks++;
+                nr_lost_events += event->lost.lost;
                 return 0;
 
         case PERF_EVENT_COMM:
@@ -1768,6 +1789,7 @@ static const char *record_args[] = {
         "-R",
         "-M",
         "-f",
+        "-m", "1024",
         "-c", "1",
         "-e", "sched:sched_switch:r",
         "-e", "sched:sched_stat_wait:r",
diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h
index fa2d4e91d329..2495529cae7d 100644
--- a/tools/perf/util/event.h
+++ b/tools/perf/util/event.h
@@ -52,7 +52,7 @@ struct lost_event {
  */
 struct read_event {
         struct perf_event_header header;
-        u32 pid,tid;
+        u32 pid, tid;
         u64 value;
         u64 time_enabled;
         u64 time_running;