perf script: Add support to display lost events

Adding option to display lost events:

  $ perf script --show-lost-events ...
   mplayer 13810 [002] 468011.402396:        100 cycles:ppp:  ff..
   mplayer 13810 [002] 468011.402396: PERF_RECORD_LOST lost 3880
   mplayer 13810 [002] 468011.402397:        100 cycles:ppp:  ff..

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180107160356.28203-10-jolsa@kernel.org
[ Use PRIu64 when printing u64 values, fixing the build in some arches ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

3 files changed, 39 insertions, 0 deletions

diff --git a/tools/perf/Documentation/perf-script.txt b/tools/perf/Documentation/perf-script.txt
index 93ae8d60e3d3..806ec6391fd6 100644
--- a/tools/perf/Documentation/perf-script.txt
+++ b/tools/perf/Documentation/perf-script.txt
@@ -300,6 +300,9 @@ OPTIONS
         Display context switch events i.e. events of type PERF_RECORD_SWITCH or
         PERF_RECORD_SWITCH_CPU_WIDE.
 
+--show-lost-events
+        Display lost events i.e. events of type PERF_RECORD_LOST.
+
 --demangle::
         Demangle symbol names to human readable form. It's enabled by default,
         disable with --no-demangle.
diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index bb603495cf4a..c1cce474c0f1 100644
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -1489,6 +1489,7 @@ struct perf_script {
         bool                    show_mmap_events;
         bool                    show_switch_events;
         bool                    show_namespace_events;
+        bool                    show_lost_events;
         bool                    allocated;
         bool                    per_event_dump;
         struct cpu_map          *cpus;
@@ -2080,6 +2081,29 @@ static int process_switch_event(struct perf_tool *tool,
         return 0;
 }
 
+static int
+process_lost_event(struct perf_tool *tool,
+                   union perf_event *event,
+                   struct perf_sample *sample,
+                   struct machine *machine)
+{
+        struct perf_script *script = container_of(tool, struct perf_script, tool);
+        struct perf_session *session = script->session;
+        struct perf_evsel *evsel = perf_evlist__id2evsel(session->evlist, sample->id);
+        struct thread *thread;
+
+        thread = machine__findnew_thread(machine, sample->pid,
+                                         sample->tid);
+        if (thread == NULL)
+                return -1;
+
+        perf_sample__fprintf_start(sample, thread, evsel,
+                                   PERF_RECORD_LOST, stdout);
+        perf_event__fprintf(event, stdout);
+        thread__put(thread);
+        return 0;
+}
+
 static void sig_handler(int sig __maybe_unused)
 {
         session_done = 1;
@@ -2174,6 +2198,8 @@ static int __cmd_script(struct perf_script *script)
                 script->tool.context_switch = process_switch_event;
         if (script->show_namespace_events)
                 script->tool.namespaces = process_namespaces_event;
+        if (script->show_lost_events)
+                script->tool.lost = process_lost_event;
 
         if (perf_script__setup_per_event_dump(script)) {
                 pr_err("Couldn't create the per event dump files\n");
@@ -3110,6 +3136,8 @@ int cmd_script(int argc, const char **argv)
                     "Show context switch events (if recorded)"),
         OPT_BOOLEAN('\0', "show-namespace-events", &script.show_namespace_events,
                     "Show namespace events (if recorded)"),
+        OPT_BOOLEAN('\0', "show-lost-events", &script.show_lost_events,
+                    "Show lost events (if recorded)"),
         OPT_BOOLEAN('\0', "per-event-dump", &script.per_event_dump,
                     "Dump trace output to files named by the monitored events"),
         OPT_BOOLEAN('f', "force", &symbol_conf.force, "don't complain, do it"),
diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index 97a8ef9980db..44e603c27944 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -1435,6 +1435,11 @@ size_t perf_event__fprintf_switch(union perf_event *event, FILE *fp)
                        event->context_switch.next_prev_tid);
 }
 
+static size_t perf_event__fprintf_lost(union perf_event *event, FILE *fp)
+{
+        return fprintf(fp, " lost %" PRIu64 "\n", event->lost.lost);
+}
+
 size_t perf_event__fprintf(union perf_event *event, FILE *fp)
 {
         size_t ret = fprintf(fp, "PERF_RECORD_%s",
@@ -1467,6 +1472,9 @@ size_t perf_event__fprintf(union perf_event *event, FILE *fp)
         case PERF_RECORD_SWITCH_CPU_WIDE:
                 ret += perf_event__fprintf_switch(event, fp);
                 break;
+        case PERF_RECORD_LOST:
+                ret += perf_event__fprintf_lost(event, fp);
+                break;
         default:
                 ret += fprintf(fp, "\n");
         }