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Commit 7ea241af authored by Yuyang Du's avatar Yuyang Du Committed by Ingo Molnar
Browse files

sched/fair: Clean up load average references 



For cfs_rq, we have load.weight, runnable_load_avg, and load_avg.
Clean up how they are used:

  - First, as group sched_entity already largely uses load_avg, we now expand
    to use load_avg in all cases.

  - Second, for CPU-wide load balancing, we choose to use runnable_load_avg
    in all cases, which is the same as before this series.

Signed-off-by: default avatarYuyang Du <yuyang.du@intel.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: arjan@linux.intel.com
Cc: bsegall@google.com
Cc: dietmar.eggemann@arm.com
Cc: fengguang.wu@intel.com
Cc: len.brown@intel.com
Cc: morten.rasmussen@arm.com
Cc: pjt@google.com
Cc: rafael.j.wysocki@intel.com
Cc: umgwanakikbuti@gmail.com
Cc: vincent.guittot@linaro.org
Link: http://lkml.kernel.org/r/1436918682-4971-8-git-send-email-yuyang.du@intel.com


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 13962234

kernel/sched/fair.c

+29 −15
Original line number Diff line number Diff line
@@ -685,6 +685,9 @@ void init_entity_runnable_average(struct sched_entity *se) 
	sa->util_sum = LOAD_AVG_MAX;

	/* when this task enqueue'ed, it will contribute to its cfs_rq's load_avg */

}



static inline unsigned long cfs_rq_runnable_load_avg(struct cfs_rq *cfs_rq);

static inline unsigned long cfs_rq_load_avg(struct cfs_rq *cfs_rq);

#else

void init_entity_runnable_average(struct sched_entity *se)

{
@@ -2360,7 +2363,7 @@ static inline long calc_tg_weight(struct task_group *tg, struct cfs_rq *cfs_rq) 
	 */

	tg_weight = atomic_long_read(&tg->load_avg);

	tg_weight -= cfs_rq->tg_load_avg_contrib;

	tg_weight += cfs_rq->avg.load_avg;

	tg_weight += cfs_rq_load_avg(cfs_rq);



	return tg_weight;

}
@@ -2370,7 +2373,7 @@ static long calc_cfs_shares(struct cfs_rq *cfs_rq, struct task_group *tg) 
	long tg_weight, load, shares;



	tg_weight = calc_tg_weight(tg, cfs_rq);

	load = cfs_rq->avg.load_avg;

	load = cfs_rq_load_avg(cfs_rq);



	shares = (tg->shares * load);

	if (tg_weight)
@@ -2796,6 +2799,16 @@ void idle_exit_fair(struct rq *this_rq) 
{

}



static inline unsigned long cfs_rq_runnable_load_avg(struct cfs_rq *cfs_rq)

{

	return cfs_rq->runnable_load_avg;

}



static inline unsigned long cfs_rq_load_avg(struct cfs_rq *cfs_rq)

{

	return cfs_rq->avg.load_avg;

}



static int idle_balance(struct rq *this_rq);



#else /* CONFIG_SMP */
@@ -4270,6 +4283,12 @@ static void __update_cpu_load(struct rq *this_rq, unsigned long this_load, 
	sched_avg_update(this_rq);

}



/* Used instead of source_load when we know the type == 0 */

static unsigned long weighted_cpuload(const int cpu)

{

	return cfs_rq_runnable_load_avg(&cpu_rq(cpu)->cfs);

}



#ifdef CONFIG_NO_HZ_COMMON

/*

 * There is no sane way to deal with nohz on smp when using jiffies because the
@@ -4291,7 +4310,7 @@ static void __update_cpu_load(struct rq *this_rq, unsigned long this_load, 
static void update_idle_cpu_load(struct rq *this_rq)

{

	unsigned long curr_jiffies = READ_ONCE(jiffies);

	unsigned long load = this_rq->cfs.avg.load_avg;

	unsigned long load = weighted_cpuload(cpu_of(this_rq));

	unsigned long pending_updates;



	/*
@@ -4337,7 +4356,7 @@ void update_cpu_load_nohz(void) 
 */

void update_cpu_load_active(struct rq *this_rq)

{

	unsigned long load = this_rq->cfs.avg.load_avg;

	unsigned long load = weighted_cpuload(cpu_of(this_rq));

	/*

	 * See the mess around update_idle_cpu_load() / update_cpu_load_nohz().

	 */
@@ -4345,12 +4364,6 @@ void update_cpu_load_active(struct rq *this_rq) 
	__update_cpu_load(this_rq, load, 1);

}



/* Used instead of source_load when we know the type == 0 */

static unsigned long weighted_cpuload(const int cpu)

{

	return cpu_rq(cpu)->cfs.avg.load_avg;

}



/*

 * Return a low guess at the load of a migration-source cpu weighted

 * according to the scheduling class and "nice" value.
@@ -4398,7 +4411,7 @@ static unsigned long cpu_avg_load_per_task(int cpu) 
{

	struct rq *rq = cpu_rq(cpu);

	unsigned long nr_running = READ_ONCE(rq->cfs.h_nr_running);

	unsigned long load_avg = rq->cfs.avg.load_avg;

	unsigned long load_avg = weighted_cpuload(cpu);



	if (nr_running)

		return load_avg / nr_running;
@@ -4517,7 +4530,7 @@ static long effective_load(struct task_group *tg, int cpu, long wl, long wg) 
		/*

		 * w = rw_i + @wl

		 */

		w = se->my_q->avg.load_avg + wl;

		w = cfs_rq_load_avg(se->my_q) + wl;



		/*

		 * wl = S * s'_i; see (2)
@@ -5862,13 +5875,14 @@ static void update_cfs_rq_h_load(struct cfs_rq *cfs_rq) 
	}



	if (!se) {

		cfs_rq->h_load = cfs_rq->avg.load_avg;

		cfs_rq->h_load = cfs_rq_load_avg(cfs_rq);

		cfs_rq->last_h_load_update = now;

	}



	while ((se = cfs_rq->h_load_next) != NULL) {

		load = cfs_rq->h_load;

		load = div64_ul(load * se->avg.load_avg, cfs_rq->avg.load_avg + 1);

		load = div64_ul(load * se->avg.load_avg,

			cfs_rq_load_avg(cfs_rq) + 1);

		cfs_rq = group_cfs_rq(se);

		cfs_rq->h_load = load;

		cfs_rq->last_h_load_update = now;
@@ -5881,7 +5895,7 @@ static unsigned long task_h_load(struct task_struct *p) 


	update_cfs_rq_h_load(cfs_rq);

	return div64_ul(p->se.avg.load_avg * cfs_rq->h_load,

			cfs_rq->avg.load_avg + 1);

			cfs_rq_load_avg(cfs_rq) + 1);

}

#else

static inline void update_blocked_averages(int cpu)