[PATCH 21/27] perf script: Add support to display lost events

From: Arnaldo Carvalho de Melo
Date: Wed Jan 10 2018 - 16:31:47 EST


From: Jiri Olsa <jolsa@xxxxxxxxxx>

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@xxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/20180107160356.28203-10-jolsa@xxxxxxxxxx
[ Use PRIu64 when printing u64 values, fixing the build in some arches ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/Documentation/perf-script.txt | 3 +++
tools/perf/builtin-script.c | 28 ++++++++++++++++++++++++++++
tools/perf/util/event.c | 8 ++++++++
3 files changed, 39 insertions(+)

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");
}
--
2.14.3