Add a function to query whether a task is currently running on any cpu.


Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>

---
 include/linux/sched.h |    5 	5 +	0 -	0 !
 kernel/sched.c        |   16 	16 +	0 -	0 !
 2 files changed, 21 insertions(+)

Index: b/include/linux/sched.h
===================================================================
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1988,8 +1988,13 @@ extern void set_task_comm(struct task_st
 extern char *get_task_comm(char *to, struct task_struct *tsk);
 
 #ifdef CONFIG_SMP
+extern int task_is_running(struct task_struct *p);
 extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
 #else
+static inline int task_is_running(struct task_struct *p)
+{
+	return p == current;
+}
 static inline unsigned long wait_task_inactive(struct task_struct *p,
 					       long match_state)
 {
Index: b/kernel/sched.c
===================================================================
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1933,6 +1933,22 @@ migrate_task(struct task_struct *p, int 
 }
 
 /*
+ * Is the task currently running on any cpu?
+ */
+int task_is_running(struct task_struct *p)
+{
+	struct rq *rq;
+	unsigned long flags;
+	int running;
+
+	rq = task_rq_lock(p, &flags);
+	running = task_running(rq, p);
+	task_rq_unlock(rq, &flags);
+
+	return running;
+}
+
+/*
  * wait_task_inactive - wait for a thread to unschedule.
  *
  * If @match_state is nonzero, it's the @p->state value just checked and

--