perf record: Add option --switch-events to select PERF_RECORD_SWITCH events
Add an option to select PERF_RECORD_SWITCH events.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Jiri Olsa <jolsa@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1437471846-26995-4-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
index 29e5307..63ee040 100644
--- a/tools/perf/Documentation/perf-record.txt
+++ b/tools/perf/Documentation/perf-record.txt
@@ -293,6 +293,10 @@
because the file may be huge. A time out is needed in such cases.
This option sets the time out limit. The default value is 500 ms.
+--switch-events::
+Record context switch events i.e. events of type PERF_RECORD_SWITCH or
+PERF_RECORD_SWITCH_CPU_WIDE.
+
SEE ALSO
--------
linkperf:perf-stat[1], linkperf:perf-list[1]
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 1932e27..445a64d 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -1075,6 +1075,8 @@
"opts", "AUX area tracing Snapshot Mode", ""),
OPT_UINTEGER(0, "proc-map-timeout", &record.opts.proc_map_timeout,
"per thread proc mmap processing timeout in ms"),
+ OPT_BOOLEAN(0, "switch-events", &record.opts.record_switch_events,
+ "Record context switch events"),
OPT_END()
};
@@ -1102,6 +1104,11 @@
" system-wide mode\n");
usage_with_options(record_usage, record_options);
}
+ if (rec->opts.record_switch_events &&
+ !perf_can_record_switch_events()) {
+ ui__error("kernel does not support recording context switch events (--switch-events option)\n");
+ usage_with_options(record_usage, record_options);
+ }
if (!rec->itr) {
rec->itr = auxtrace_record__init(rec->evlist, &err);
diff --git a/tools/perf/perf.h b/tools/perf/perf.h
index 937b16a..cf459f8 100644
--- a/tools/perf/perf.h
+++ b/tools/perf/perf.h
@@ -57,6 +57,7 @@
bool running_time;
bool full_auxtrace;
bool auxtrace_snapshot_mode;
+ bool record_switch_events;
unsigned int freq;
unsigned int mmap_pages;
unsigned int auxtrace_mmap_pages;
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index 406a821..a8930b6 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -114,6 +114,7 @@
void perf_evlist__set_id_pos(struct perf_evlist *evlist);
bool perf_can_sample_identifier(void);
+bool perf_can_record_switch_events(void);
void perf_evlist__config(struct perf_evlist *evlist, struct record_opts *opts);
int record_opts__config(struct record_opts *opts);
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 9e6e6f4..71f6905 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -738,6 +738,9 @@
attr->mmap2 = track && !perf_missing_features.mmap2;
attr->comm = track;
+ if (opts->record_switch_events)
+ attr->context_switch = track;
+
if (opts->sample_transaction)
perf_evsel__set_sample_bit(evsel, TRANSACTION);
diff --git a/tools/perf/util/record.c b/tools/perf/util/record.c
index 1f7becb..0d228a2 100644
--- a/tools/perf/util/record.c
+++ b/tools/perf/util/record.c
@@ -85,6 +85,11 @@
evsel->attr.comm_exec = 1;
}
+static void perf_probe_context_switch(struct perf_evsel *evsel)
+{
+ evsel->attr.context_switch = 1;
+}
+
bool perf_can_sample_identifier(void)
{
return perf_probe_api(perf_probe_sample_identifier);
@@ -95,6 +100,11 @@
return perf_probe_api(perf_probe_comm_exec);
}
+bool perf_can_record_switch_events(void)
+{
+ return perf_probe_api(perf_probe_context_switch);
+}
+
void perf_evlist__config(struct perf_evlist *evlist, struct record_opts *opts)
{
struct perf_evsel *evsel;