perfcounters: fix task clock counter

Impact: fix per task clock counter precision

Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 12 insertions, 5 deletions

diff --git a/kernel/exit.c b/kernel/exit.c
index d336c90a5f13..244edfd96865 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -922,6 +922,12 @@ static void exit_notify(struct task_struct *tsk, int group_dead)
         forget_original_parent(tsk);
         exit_task_namespaces(tsk);
 
+        /*
+         * Flush inherited counters to the parent - before the parent
+         * gets woken up by child-exit notifications.
+         */
+        perf_counter_exit_task(tsk);
+
         write_lock_irq(&tasklist_lock);
         if (group_dead)
                 kill_orphaned_pgrp(tsk->group_leader, NULL);
@@ -1093,11 +1099,6 @@ NORET_TYPE void do_exit(long code)
         mpol_put(tsk->mempolicy);
         tsk->mempolicy = NULL;
 #endif
-        /*
-         * These must happen late, after the PID is not
-         * hashed anymore, but still at a point that may sleep:
-         */
-        perf_counter_exit_task(tsk);
 #ifdef CONFIG_FUTEX
         if (unlikely(!list_empty(&tsk->pi_state_list)))
                 exit_pi_state_list(tsk);
@@ -1121,6 +1122,12 @@ NORET_TYPE void do_exit(long code)
         if (tsk->splice_pipe)
                 __free_pipe_info(tsk->splice_pipe);
 
+        /*
+         * These must happen late, after the PID is not
+         * hashed anymore, but still at a point that may sleep:
+         */
+        perf_counter_exit_task(tsk);
+
         preempt_disable();
         /* causes final put_task_struct in finish_task_switch(). */
         tsk->state = TASK_DEAD;