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Commit e418e1c2 authored by Christoph Lameter's avatar Christoph Lameter Committed by Linus Torvalds
Browse files

[PATCH] sched: move idle status calculation into rebalance_tick() 



Perform the idle state determination in rebalance_tick.

If we separate balancing from sched_tick then we also need to determine the
idle state in rebalance_tick.

V2->V3
	Remove useless idlle != 0 check. Checking nr_running seems
	to be sufficient. Thanks Suresh.

Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
Cc: Peter Williams <pwil3058@bigpond.net.au>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com>
Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com>
Acked-by: default avatarIngo Molnar <mingo@elte.hu>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 7835b98b

kernel/sched.c

+16 −21
Original line number Diff line number Diff line
@@ -2867,10 +2867,16 @@ static void update_load(struct rq *this_rq) 
 */



static void

rebalance_tick(int this_cpu, struct rq *this_rq, enum idle_type idle)

rebalance_tick(int this_cpu, struct rq *this_rq)

{

	unsigned long interval;

	struct sched_domain *sd;

	/*

	 * We are idle if there are no processes running. This

	 * is valid even if we are the idle process (SMT).

	 */

	enum idle_type idle = !this_rq->nr_running ?

				SCHED_IDLE : NOT_IDLE;



	for_each_domain(this_cpu, sd) {

		if (!(sd->flags & SD_LOAD_BALANCE))
@@ -2902,37 +2908,26 @@ rebalance_tick(int this_cpu, struct rq *this_rq, enum idle_type idle) 
/*

 * on UP we do not need to balance between CPUs:

 */

static inline void rebalance_tick(int cpu, struct rq *rq)

{

}

static inline void idle_balance(int cpu, struct rq *rq)

{

}

static inline void update_load(struct rq *this_rq)

{

}

#endif



static inline int wake_priority_sleeper(struct rq *rq)

static inline void wake_priority_sleeper(struct rq *rq)

{

	int ret = 0;



#ifdef CONFIG_SCHED_SMT

	if (!rq->nr_running)

		return 0;

		return;



	spin_lock(&rq->lock);

	/*

	 * If an SMT sibling task has been put to sleep for priority

	 * reasons reschedule the idle task to see if it can now run.

	 */

	if (rq->nr_running) {

	if (rq->nr_running)

		resched_task(rq->idle);

		ret = 1;

	}

	spin_unlock(&rq->lock);

#endif

	return ret;

}



DEFINE_PER_CPU(struct kernel_stat, kstat);
@@ -3148,20 +3143,20 @@ void scheduler_tick(void) 
	struct task_struct *p = current;

	int cpu = smp_processor_id();

	struct rq *rq = cpu_rq(cpu);

	enum idle_type idle = NOT_IDLE;



	update_cpu_clock(p, rq, now);



	rq->timestamp_last_tick = now;



	if (p == rq->idle) {

	if (p == rq->idle)

		/* Task on the idle queue */

		if (!wake_priority_sleeper(rq))

			idle = SCHED_IDLE;

	} else

		wake_priority_sleeper(rq);

	else

		task_running_tick(rq, p);

#ifdef CONFIG_SMP

	update_load(rq);

	rebalance_tick(cpu, rq, idle);

	rebalance_tick(cpu, rq);

#endif

}



#ifdef CONFIG_SCHED_SMT