[PATCH] perf: Add a timestamp to fork events

[Arjan van de Ven]

timechart needs to know when a process forked, in order to be able
to visualize properly when tasks start.

This patch adds a time field to the event structure, and fills it
in appropriately.

Signed-off-by: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx>
---
 include/linux/perf_counter.h |    2 ++
 kernel/perf_counter.c        |   11 +++++++++--
 tools/perf/util/event.h      |    1 +
 3 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h
index 972f90d..5fe6898 100644
--- a/include/linux/perf_counter.h
+++ b/include/linux/perf_counter.h
@@ -332,6 +332,7 @@ enum perf_event_type {
 	 *	struct perf_event_header	header;
 	 *	u32				pid, ppid;
 	 *	u32				tid, ptid;
+	 *	u64				time;
 	 * };
 	 */
 	PERF_EVENT_EXIT			= 4,
@@ -352,6 +353,7 @@ enum perf_event_type {
 	 *	struct perf_event_header	header;
 	 *	u32				pid, ppid;
 	 *	u32				tid, ptid;
+	 *	{ u64				time;     } && PERF_SAMPLE_TIME
 	 * };
 	 */
 	PERF_EVENT_FORK			= 7,
diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c
index e0d91fd..25490db 100644
--- a/kernel/perf_counter.c
+++ b/kernel/perf_counter.c
@@ -3071,6 +3071,7 @@ struct perf_task_event {
 		u32				ppid;
 		u32				tid;
 		u32				ptid;
+		u64				time;
 	} event;
 };
 
@@ -3078,9 +3079,12 @@ static void perf_counter_task_output(struct perf_counter *counter,
 				     struct perf_task_event *task_event)
 {
 	struct perf_output_handle handle;
-	int size = task_event->event.header.size;
+	int size;
 	struct task_struct *task = task_event->task;
-	int ret = perf_output_begin(&handle, counter, size, 0, 0);
+	int ret;
+
+	size  = task_event->event.header.size;
+	ret = perf_output_begin(&handle, counter, size, 0, 0);
 
 	if (ret)
 		return;
@@ -3091,7 +3095,10 @@ static void perf_counter_task_output(struct perf_counter *counter,
 	task_event->event.tid = perf_counter_tid(counter, task);
 	task_event->event.ptid = perf_counter_tid(counter, current);
 
+	task_event->event.time = sched_clock();
+
 	perf_output_put(&handle, task_event->event);
+
 	perf_output_end(&handle);
 }
 
diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h
index fa2d4e9..1545349 100644
--- a/tools/perf/util/event.h
+++ b/tools/perf/util/event.h
@@ -39,6 +39,7 @@ struct fork_event {
 	struct perf_event_header header;
 	u32 pid, ppid;
 	u32 tid, ptid;
+	u64 time;
 };
 
 struct lost_event {
-- 
1.6.0.6



-- 
Arjan van de Ven 	Intel Open Source Technology Centre
For development, discussion and tips for power savings, 
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