perf db-export: Export switch events

Export details of switch events including the threads and their current
comms.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20190710085810.1650-20-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 89 insertions, 0 deletions

diff --git a/tools/perf/util/db-export.c b/tools/perf/util/db-export.c
index e6a9c450133e..ffbb3e7d3288 100644
--- a/tools/perf/util/db-export.c
+++ b/tools/perf/util/db-export.c
@@ -519,3 +519,92 @@ int db_export__call_return(struct db_export *dbe, struct call_return *cr,
 
 	return 0;
 }
+
+static int db_export__pid_tid(struct db_export *dbe, struct machine *machine,
+			      pid_t pid, pid_t tid, u64 *db_id,
+			      struct comm **comm_ptr, bool *is_idle)
+{
+	struct thread *thread = machine__find_thread(machine, pid, tid);
+	struct thread *main_thread;
+	int err = 0;
+
+	if (!thread || !thread->comm_set)
+		goto out_put;
+
+	*is_idle = !thread->pid_ && !thread->tid;
+
+	main_thread = thread__main_thread(machine, thread);
+
+	err = db_export__threads(dbe, thread, main_thread, machine, comm_ptr);
+
+	*db_id = thread->db_id;
+
+	thread__put(main_thread);
+out_put:
+	thread__put(thread);
+
+	return err;
+}
+
+int db_export__switch(struct db_export *dbe, union perf_event *event,
+		      struct perf_sample *sample, struct machine *machine)
+{
+	bool out = event->header.misc & PERF_RECORD_MISC_SWITCH_OUT;
+	bool out_preempt = out &&
+		(event->header.misc & PERF_RECORD_MISC_SWITCH_OUT_PREEMPT);
+	int flags = out | (out_preempt << 1);
+	bool is_idle_a = false, is_idle_b = false;
+	u64 th_a_id = 0, th_b_id = 0;
+	u64 comm_out_id, comm_in_id;
+	struct comm *comm_a = NULL;
+	struct comm *comm_b = NULL;
+	u64 th_out_id, th_in_id;
+	u64 db_id;
+	int err;
+
+	err = db_export__machine(dbe, machine);
+	if (err)
+		return err;
+
+	err = db_export__pid_tid(dbe, machine, sample->pid, sample->tid,
+				 &th_a_id, &comm_a, &is_idle_a);
+	if (err)
+		return err;
+
+	if (event->header.type == PERF_RECORD_SWITCH_CPU_WIDE) {
+		pid_t pid = event->context_switch.next_prev_pid;
+		pid_t tid = event->context_switch.next_prev_tid;
+
+		err = db_export__pid_tid(dbe, machine, pid, tid, &th_b_id,
+					 &comm_b, &is_idle_b);
+		if (err)
+			return err;
+	}
+
+	/*
+	 * Do not export if both threads are unknown (i.e. not being traced),
+	 * or one is unknown and the other is the idle task.
+	 */
+	if ((!th_a_id || is_idle_a) && (!th_b_id || is_idle_b))
+		return 0;
+
+	db_id = ++dbe->context_switch_last_db_id;
+
+	if (out) {
+		th_out_id   = th_a_id;
+		th_in_id    = th_b_id;
+		comm_out_id = comm_a ? comm_a->db_id : 0;
+		comm_in_id  = comm_b ? comm_b->db_id : 0;
+	} else {
+		th_out_id   = th_b_id;
+		th_in_id    = th_a_id;
+		comm_out_id = comm_b ? comm_b->db_id : 0;
+		comm_in_id  = comm_a ? comm_a->db_id : 0;
+	}
+
+	if (dbe->export_context_switch)
+		return dbe->export_context_switch(dbe, db_id, machine, sample,
+						  th_out_id, comm_out_id,
+						  th_in_id, comm_in_id, flags);
+	return 0;
+}