perf script: Add option --show-switch-events

Add option --show-switch-events to show switch events in a similar
fashion to --show-task-events and --show-mmap-events.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Jiri Olsa <jolsa@redhat.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1437471846-26995-6-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

2 files changed, 35 insertions, 0 deletions

diff --git a/tools/perf/Documentation/perf-script.txt b/tools/perf/Documentation/perf-script.txt
index c82df572fac2..e2fec5fc21e7 100644
--- a/tools/perf/Documentation/perf-script.txt
+++ b/tools/perf/Documentation/perf-script.txt
@@ -222,6 +222,10 @@ OPTIONS
 --show-mmap-events
         Display mmap related events (e.g. MMAP, MMAP2).
 
+--show-switch-events
+        Display context switch events i.e. events of type PERF_RECORD_SWITCH or
+        PERF_RECORD_SWITCH_CPU_WIDE.
+
 --header
         Show perf.data header.
 
diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index 8a8e2ead6382..bd31380122f9 100644
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -623,6 +623,7 @@ struct perf_script {
         struct perf_session     *session;
         bool                    show_task_events;
         bool                    show_mmap_events;
+        bool                    show_switch_events;
 };
 
 static int process_attr(struct perf_tool *tool, union perf_event *event,
@@ -813,6 +814,32 @@ static int process_mmap2_event(struct perf_tool *tool,
         return 0;
 }
 
+static int process_switch_event(struct perf_tool *tool,
+                                union perf_event *event,
+                                struct perf_sample *sample,
+                                struct machine *machine)
+{
+        struct thread *thread;
+        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);
+
+        if (perf_event__process_switch(tool, event, sample, machine) < 0)
+                return -1;
+
+        thread = machine__findnew_thread(machine, sample->pid,
+                                         sample->tid);
+        if (thread == NULL) {
+                pr_debug("problem processing SWITCH event, skipping it.\n");
+                return -1;
+        }
+
+        print_sample_start(sample, thread, evsel);
+        perf_event__fprintf(event, stdout);
+        thread__put(thread);
+        return 0;
+}
+
 static void sig_handler(int sig __maybe_unused)
 {
         session_done = 1;
@@ -834,6 +861,8 @@ static int __cmd_script(struct perf_script *script)
                 script->tool.mmap = process_mmap_event;
                 script->tool.mmap2 = process_mmap2_event;
         }
+        if (script->show_switch_events)
+                script->tool.context_switch = process_switch_event;
 
         ret = perf_session__process_events(script->session);
 
@@ -1618,6 +1647,8 @@ int cmd_script(int argc, const char **argv, const char *prefix __maybe_unused)
                     "Show the fork/comm/exit events"),
         OPT_BOOLEAN('\0', "show-mmap-events", &script.show_mmap_events,
                     "Show the mmap events"),
+        OPT_BOOLEAN('\0', "show-switch-events", &script.show_switch_events,
+                    "Show context switch events (if recorded)"),
         OPT_BOOLEAN('f', "force", &file.force, "don't complain, do it"),
         OPT_CALLBACK_OPTARG(0, "itrace", &itrace_synth_opts, NULL, "opts",
                             "Instruction Tracing options",