[PATCH 19/21] perf db-export: Export switch events

Adrian Hunter
2019-07-10T08:59:59Z

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

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
tools/perf/util/db-export.c | 89 +++++++++++++++++++
tools/perf/util/db-export.h | 8 ++
.../scripting-engines/trace-event-python.c | 41 +++++++++
3 files changed, 138 insertions(+)

diff --git a/tools/perf/util/db-export.c b/tools/perf/util/db-export.c
index 2efc08b74176..cd32147aa2a3 100644
--- a/tools/perf/util/db-export.c
+++ b/tools/perf/util/db-export.c
@@ -518,3 +518,92 @@ 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;
+}
diff --git a/tools/perf/util/db-export.h b/tools/perf/util/db-export.h
index f5f0865f07e1..ba1f62a5fe10 100644
--- a/tools/perf/util/db-export.h
+++ b/tools/perf/util/db-export.h
@@ -57,6 +57,11 @@ struct db_export {
int (*export_call_path)(struct db_export *dbe, struct call_path *cp);
int (*export_call_return)(struct db_export *dbe,
struct call_return *cr);
+ int (*export_context_switch)(struct db_export *dbe, u64 db_id,
+ struct machine *machine,
+ struct perf_sample *sample,
+ u64 th_out_id, u64 comm_out_id,
+ u64 th_in_id, u64 comm_in_id, int flags);
struct call_return_processor *crp;
struct call_path_root *cpr;
u64 evsel_last_db_id;
@@ -69,6 +74,7 @@ struct db_export {
u64 sample_last_db_id;
u64 call_path_last_db_id;
u64 call_return_last_db_id;
+ u64 context_switch_last_db_id;
};

int db_export__init(struct db_export *dbe);
@@ -98,5 +104,7 @@ int db_export__branch_types(struct db_export *dbe);
int db_export__call_path(struct db_export *dbe, struct call_path *cp);
int db_export__call_return(struct db_export *dbe, struct call_return *cr,
u64 *parent_db_id);
+int db_export__switch(struct db_export *dbe, union perf_event *event,
+ struct perf_sample *sample, struct machine *machine);

#endif
diff --git a/tools/perf/util/scripting-engines/trace-event-python.c b/tools/perf/util/scripting-engines/trace-event-python.c
index 28167e938cef..25dc1d765553 100644
--- a/tools/perf/util/scripting-engines/trace-event-python.c
+++ b/tools/perf/util/scripting-engines/trace-event-python.c
@@ -113,6 +113,7 @@ struct tables {
PyObject *call_path_handler;
PyObject *call_return_handler;
PyObject *synth_handler;
+ PyObject *context_switch_handler;
bool db_export_mode;
};

@@ -1237,6 +1238,34 @@ static int python_export_call_return(struct db_export *dbe,
return 0;
}

+static int python_export_context_switch(struct db_export *dbe, u64 db_id,
+ struct machine *machine,
+ struct perf_sample *sample,
+ u64 th_out_id, u64 comm_out_id,
+ u64 th_in_id, u64 comm_in_id, int flags)
+{
+ struct tables *tables = container_of(dbe, struct tables, dbe);
+ PyObject *t;
+
+ t = tuple_new(9);
+
+ tuple_set_u64(t, 0, db_id);
+ tuple_set_u64(t, 1, machine->db_id);
+ tuple_set_u64(t, 2, sample->time);
+ tuple_set_s32(t, 3, sample->cpu);
+ tuple_set_u64(t, 4, th_out_id);
+ tuple_set_u64(t, 5, comm_out_id);
+ tuple_set_u64(t, 6, th_in_id);
+ tuple_set_u64(t, 7, comm_in_id);
+ tuple_set_s32(t, 8, flags);
+
+ call_object(tables->context_switch_handler, t, "context_switch");
+
+ Py_DECREF(t);
+
+ return 0;
+}
+
static int python_process_call_return(struct call_return *cr, u64 *parent_db_id,
void *data)
{
@@ -1300,6 +1329,16 @@ static void python_process_event(union perf_event *event,
}
}

+static void python_process_switch(union perf_event *event,
+ struct perf_sample *sample,
+ struct machine *machine)
+{
+ struct tables *tables = &tables_global;
+
+ if (tables->db_export_mode)
+ db_export__switch(&tables->dbe, event, sample, machine);
+}
+
static void get_handler_name(char *str, size_t size,
struct perf_evsel *evsel)
{
@@ -1515,6 +1554,7 @@ static void set_table_handlers(struct tables *tables)
SET_TABLE_HANDLER(sample);
SET_TABLE_HANDLER(call_path);
SET_TABLE_HANDLER(call_return);
+ SET_TABLE_HANDLER(context_switch);

/*
* Synthesized events are samples but with architecture-specific data
@@ -1833,6 +1873,7 @@ struct scripting_ops python_scripting_ops = {
.flush_script = python_flush_script,
.stop_script = python_stop_script,
.process_event = python_process_event,
+ .process_switch = python_process_switch,
.process_stat = python_process_stat,
.process_stat_interval = python_process_stat_interval,
.generate_script = python_generate_script,
--
2.17.1