[RFC][PATCH 01/22] sched: add sched_class->task_dead.

[Raistlin]

Add a new function to the scheduling class interface. It is called
at the end of a context switch, if the prev task is in TASK_DEAD state.

It might be useful for the scheduling classes that want to be notified
when one of their task dies, e.g. to perform some cleanup actions.

Signed-off-by: Dario Faggioli <raistlin@xxxxxxxx>
---
 include/linux/sched.h |    1 +
 kernel/sched.c        |    3 +++
 2 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/include/linux/sched.h b/include/linux/sched.h
index b3d07df..6053b4b 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1068,6 +1068,7 @@ struct sched_class {
 	void (*set_curr_task) (struct rq *rq);
 	void (*task_tick) (struct rq *rq, struct task_struct *p, int queued);
 	void (*task_fork) (struct task_struct *p);
+	void (*task_dead) (struct task_struct *p);
 
 	void (*switched_from) (struct rq *this_rq, struct task_struct *task,
 			       int running);
diff --git a/kernel/sched.c b/kernel/sched.c
index 41f1869..07f5a0c 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2891,6 +2891,9 @@ static void finish_task_switch(struct rq *rq, struct task_struct *prev)
 	if (mm)
 		mmdrop(mm);
 	if (unlikely(prev_state == TASK_DEAD)) {
+		if (prev->sched_class->task_dead)
+			prev->sched_class->task_dead(prev);
+
 		/*
 		 * Remove function-return probe instances associated with this
 		 * task and put them back on the free list.
-- 
1.7.2.3


-- 
<<This happens because I choose it to happen!>> (Raistlin Majere)
----------------------------------------------------------------------
Dario Faggioli, ReTiS Lab, Scuola Superiore Sant'Anna, Pisa  (Italy)

http://blog.linux.it/raistlin / raistlin@xxxxxxxxx /
dario.faggioli@xxxxxxxxxx

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