perf script: Add scripting operation process_switch()

Add scripting operation process_switch() to process switch events.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20190710085810.1650-18-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-script.c

@@ -2289,6 +2289,12 @@ static int process_switch_event(struct perf_tool *tool,
 	if (perf_event__process_switch(tool, event, sample, machine) < 0)
 		return -1;
 
+	if (scripting_ops && scripting_ops->process_switch)
+		scripting_ops->process_switch(event, sample, machine);
+
+	if (!script->show_switch_events)
+		return 0;
+
 	thread = machine__findnew_thread(machine, sample->pid,
 					 sample->tid);
 	if (thread == NULL) {
@@ -2467,7 +2473,7 @@ 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)
+	if (script->show_switch_events || (scripting_ops && scripting_ops->process_switch))
 		script->tool.context_switch = process_switch_event;
 	if (script->show_namespace_events)
 		script->tool.namespaces = process_namespaces_event;

tools/perf/util/trace-event.h

@@ -81,6 +81,9 @@ struct scripting_ops {
 			       struct perf_sample *sample,
 			       struct perf_evsel *evsel,
 			       struct addr_location *al);
+	void (*process_switch)(union perf_event *event,
+			       struct perf_sample *sample,
+			       struct machine *machine);
 	void (*process_stat)(struct perf_stat_config *config,
 			     struct perf_evsel *evsel, u64 tstamp);
 	void (*process_stat_interval)(u64 tstamp);