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Commit 2caf4703 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'for-linus' of... 

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched-devel

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched-devel:
  sched: tune multi-core idle balancing
  sched: retune wake granularity
  sched: wakeup-buddy tasks are cache-hot
  sched: improve affine wakeups
  sched, net: socket wakeups are sync
  sched: clean up wakeup balancing, code flow
  sched: clean up wakeup balancing, rename variables
  sched: clean up wakeup balancing, move wake_affine()
parents 6c3c3158 33b0c421

include/linux/sched.h

+3 −0
Original line number Diff line number Diff line
@@ -929,6 +929,9 @@ struct sched_entity { 
	u64			vruntime;

	u64			prev_sum_exec_runtime;



	u64			last_wakeup;

	u64			avg_overlap;



#ifdef CONFIG_SCHEDSTATS

	u64			wait_start;

	u64			wait_max;

include/linux/topology.h

+0 −1
Original line number Diff line number Diff line
@@ -138,7 +138,6 @@ 
				| SD_BALANCE_FORK	\

				| SD_BALANCE_EXEC	\

				| SD_WAKE_AFFINE	\

				| SD_WAKE_IDLE		\

				| SD_SHARE_PKG_RESOURCES\

				| BALANCE_FOR_MC_POWER,	\

	.last_balance		= jiffies,		\

kernel/sched.c

+10 −1
Original line number Diff line number Diff line
@@ -1396,6 +1396,12 @@ task_hot(struct task_struct *p, u64 now, struct sched_domain *sd) 
{

	s64 delta;



	/*

	 * Buddy candidates are cache hot:

	 */

	if (&p->se == cfs_rq_of(&p->se)->next)

		return 1;



	if (p->sched_class != &fair_sched_class)

		return 0;
@@ -1855,10 +1861,11 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync) 
		schedstat_inc(p, se.nr_wakeups_remote);

	update_rq_clock(rq);

	activate_task(rq, p, 1);

	check_preempt_curr(rq, p);

	success = 1;



out_running:

	check_preempt_curr(rq, p);



	p->state = TASK_RUNNING;

#ifdef CONFIG_SMP

	if (p->sched_class->task_wake_up)
@@ -1892,6 +1899,8 @@ static void __sched_fork(struct task_struct *p) 
	p->se.exec_start		= 0;

	p->se.sum_exec_runtime		= 0;

	p->se.prev_sum_exec_runtime	= 0;

	p->se.last_wakeup		= 0;

	p->se.avg_overlap		= 0;



#ifdef CONFIG_SCHEDSTATS

	p->se.wait_start		= 0;

kernel/sched_debug.c

+1 −0
Original line number Diff line number Diff line
@@ -288,6 +288,7 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m) 
	PN(se.exec_start);

	PN(se.vruntime);

	PN(se.sum_exec_runtime);

	PN(se.avg_overlap);



	nr_switches = p->nvcsw + p->nivcsw;

kernel/sched_fair.c

+118 −73
Original line number Diff line number Diff line
@@ -73,13 +73,13 @@ unsigned int sysctl_sched_batch_wakeup_granularity = 10000000UL; 


/*

 * SCHED_OTHER wake-up granularity.

 * (default: 10 msec * (1 + ilog(ncpus)), units: nanoseconds)

 * (default: 5 msec * (1 + ilog(ncpus)), units: nanoseconds)

 *

 * This option delays the preemption effects of decoupled workloads

 * and reduces their over-scheduling. Synchronous workloads will still

 * have immediate wakeup/sleep latencies.

 */

unsigned int sysctl_sched_wakeup_granularity = 10000000UL;

unsigned int sysctl_sched_wakeup_granularity = 5000000UL;



const_debug unsigned int sysctl_sched_migration_cost = 500000UL;
@@ -556,6 +556,21 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int wakeup) 
	account_entity_enqueue(cfs_rq, se);

}



static void update_avg(u64 *avg, u64 sample)

{

	s64 diff = sample - *avg;

	*avg += diff >> 3;

}



static void update_avg_stats(struct cfs_rq *cfs_rq, struct sched_entity *se)

{

	if (!se->last_wakeup)

		return;



	update_avg(&se->avg_overlap, se->sum_exec_runtime - se->last_wakeup);

	se->last_wakeup = 0;

}



static void

dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep)

{
@@ -566,6 +581,7 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep) 


	update_stats_dequeue(cfs_rq, se);

	if (sleep) {

		update_avg_stats(cfs_rq, se);

#ifdef CONFIG_SCHEDSTATS

		if (entity_is_task(se)) {

			struct task_struct *tsk = task_of(se);
@@ -980,55 +996,32 @@ static inline int wake_idle(int cpu, struct task_struct *p) 
#endif



#ifdef CONFIG_SMP

static int select_task_rq_fair(struct task_struct *p, int sync)

{

	int cpu, this_cpu;

	struct rq *rq;

	struct sched_domain *sd, *this_sd = NULL;

	int new_cpu;



	cpu      = task_cpu(p);

	rq       = task_rq(p);

	this_cpu = smp_processor_id();

	new_cpu  = cpu;



	if (cpu == this_cpu)

		goto out_set_cpu;



	for_each_domain(this_cpu, sd) {

		if (cpu_isset(cpu, sd->span)) {

			this_sd = sd;

			break;

		}

	}



	if (unlikely(!cpu_isset(this_cpu, p->cpus_allowed)))

		goto out_set_cpu;



	/*

	 * Check for affine wakeup and passive balancing possibilities.

	 */

	if (this_sd) {

		int idx = this_sd->wake_idx;

		unsigned int imbalance;

		unsigned long load, this_load;

static const struct sched_class fair_sched_class;



		imbalance = 100 + (this_sd->imbalance_pct - 100) / 2;



		load = source_load(cpu, idx);

		this_load = target_load(this_cpu, idx);



		new_cpu = this_cpu; /* Wake to this CPU if we can */



		if (this_sd->flags & SD_WAKE_AFFINE) {

static int

wake_affine(struct rq *rq, struct sched_domain *this_sd, struct rq *this_rq,

	    struct task_struct *p, int prev_cpu, int this_cpu, int sync,

	    int idx, unsigned long load, unsigned long this_load,

	    unsigned int imbalance)

{

	struct task_struct *curr = this_rq->curr;

	unsigned long tl = this_load;

	unsigned long tl_per_task;



	if (!(this_sd->flags & SD_WAKE_AFFINE))

		return 0;



	/*

			 * Attract cache-cold tasks on sync wakeups:

	 * If the currently running task will sleep within

	 * a reasonable amount of time then attract this newly

	 * woken task:

	 */

			if (sync && !task_hot(p, rq->clock, this_sd))

				goto out_set_cpu;

	if (sync && curr->sched_class == &fair_sched_class) {

		if (curr->se.avg_overlap < sysctl_sched_migration_cost &&

				p->se.avg_overlap < sysctl_sched_migration_cost)

			return 1;

	}



	schedstat_inc(p, se.nr_wakeups_affine_attempts);

	tl_per_task = cpu_avg_load_per_task(this_cpu);
@@ -1041,8 +1034,7 @@ static int select_task_rq_fair(struct task_struct *p, int sync) 
	if (sync)

		tl -= current->se.load.weight;



			if ((tl <= load &&

				tl + target_load(cpu, idx) <= tl_per_task) ||

	if ((tl <= load && tl + target_load(prev_cpu, idx) <= tl_per_task) ||

			100*(tl + p->se.load.weight) <= imbalance*load) {

		/*

		 * This domain has SD_WAKE_AFFINE and
@@ -1051,10 +1043,61 @@ static int select_task_rq_fair(struct task_struct *p, int sync) 
		 */

		schedstat_inc(this_sd, ttwu_move_affine);

		schedstat_inc(p, se.nr_wakeups_affine);

				goto out_set_cpu;



		return 1;

	}

	return 0;

}



static int select_task_rq_fair(struct task_struct *p, int sync)

{

	struct sched_domain *sd, *this_sd = NULL;

	int prev_cpu, this_cpu, new_cpu;

	unsigned long load, this_load;

	struct rq *rq, *this_rq;

	unsigned int imbalance;

	int idx;



	prev_cpu	= task_cpu(p);

	rq		= task_rq(p);

	this_cpu	= smp_processor_id();

	this_rq		= cpu_rq(this_cpu);

	new_cpu		= prev_cpu;



	/*

	 * 'this_sd' is the first domain that both

	 * this_cpu and prev_cpu are present in:

	 */

	for_each_domain(this_cpu, sd) {

		if (cpu_isset(prev_cpu, sd->span)) {

			this_sd = sd;

			break;

		}

	}



	if (unlikely(!cpu_isset(this_cpu, p->cpus_allowed)))

		goto out;



	/*

	 * Check for affine wakeup and passive balancing possibilities.

	 */

	if (!this_sd)

		goto out;



	idx = this_sd->wake_idx;



	imbalance = 100 + (this_sd->imbalance_pct - 100) / 2;



	load = source_load(prev_cpu, idx);

	this_load = target_load(this_cpu, idx);



	if (wake_affine(rq, this_sd, this_rq, p, prev_cpu, this_cpu, sync, idx,

				     load, this_load, imbalance))

		return this_cpu;



	if (prev_cpu == this_cpu)

		goto out;



	/*

	 * Start passive balancing when half the imbalance_pct

	 * limit is reached.
@@ -1063,13 +1106,11 @@ static int select_task_rq_fair(struct task_struct *p, int sync) 
		if (imbalance*this_load <= 100*load) {

			schedstat_inc(this_sd, ttwu_move_balance);

			schedstat_inc(p, se.nr_wakeups_passive);

				goto out_set_cpu;

			}

			return this_cpu;

		}

	}



	new_cpu = cpu; /* Could not wake to this_cpu. Wake to cpu instead */

out_set_cpu:

out:

	return wake_idle(new_cpu, p);

}

#endif /* CONFIG_SMP */
@@ -1092,6 +1133,10 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p) 
		return;

	}



	se->last_wakeup = se->sum_exec_runtime;

	if (unlikely(se == pse))

		return;



	cfs_rq_of(pse)->next = pse;



	/*