perf: Add a timestamp to fork events

perf 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@linux.intel.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20090912130341.51ad2de2@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

3 files changed, 12 insertions, 2 deletions

diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h
index c7375f97aa19..bd341007c4fc 100644
--- a/include/linux/perf_counter.h
+++ b/include/linux/perf_counter.h
@@ -336,6 +336,7 @@ enum perf_event_type {
          *      struct perf_event_header        header;
          *      u32                             pid, ppid;
          *      u32                             tid, ptid;
+         *      u64                             time;
          * };
          */
         PERF_EVENT_EXIT                 = 4,
@@ -356,6 +357,7 @@ 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 d013f4e89e9c..d5899b62b276 100644
--- a/kernel/perf_counter.c
+++ b/kernel/perf_counter.c
@@ -3083,6 +3083,7 @@ struct perf_task_event {
                 u32                             ppid;
                 u32                             tid;
                 u32                             ptid;
+                u64                             time;
         } event;
 };
 
@@ -3090,9 +3091,12 @@ 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;
@@ -3103,7 +3107,10 @@ 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 = perf_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 2495529cae7d..28a579f8fa8e 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 {