Commit 68767a0a authored by Nicholas Piggin's avatar Nicholas Piggin Committed by Linus Torvalds
Browse files

[PATCH] sched: schedstats update for balance on fork 



Add SCHEDSTAT statistics for sched-balance-fork.

Signed-off-by: default avatarNick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 147cbb4b

include/linux/sched.h

+8 −2
Original line number Diff line number Diff line
@@ -517,10 +517,16 @@ struct sched_domain { 
	unsigned long alb_failed;

	unsigned long alb_pushed;



	/* sched_balance_exec() stats */

	unsigned long sbe_attempts;

	/* SD_BALANCE_EXEC stats */

	unsigned long sbe_cnt;

	unsigned long sbe_balanced;

	unsigned long sbe_pushed;



	/* SD_BALANCE_FORK stats */

	unsigned long sbf_cnt;

	unsigned long sbf_balanced;

	unsigned long sbf_pushed;



	/* try_to_wake_up() stats */

	unsigned long ttwu_wake_remote;

	unsigned long ttwu_move_affine;

kernel/sched.c

+36 −27
Original line number Diff line number Diff line
@@ -309,7 +309,7 @@ static inline void task_rq_unlock(runqueue_t *rq, unsigned long *flags) 
 * bump this up when changing the output format or the meaning of an existing

 * format, so that tools can adapt (or abort)

 */

#define SCHEDSTAT_VERSION 11

#define SCHEDSTAT_VERSION 12



static int show_schedstat(struct seq_file *seq, void *v)

{
@@ -356,9 +356,10 @@ static int show_schedstat(struct seq_file *seq, void *v) 
				    sd->lb_nobusyq[itype],

				    sd->lb_nobusyg[itype]);

			}

			seq_printf(seq, " %lu %lu %lu %lu %lu %lu %lu %lu\n",

			seq_printf(seq, " %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu\n",

			    sd->alb_cnt, sd->alb_failed, sd->alb_pushed,

			    sd->sbe_pushed, sd->sbe_attempts,

			    sd->sbe_cnt, sd->sbe_balanced, sd->sbe_pushed,

			    sd->sbf_cnt, sd->sbf_balanced, sd->sbf_pushed,

			    sd->ttwu_wake_remote, sd->ttwu_move_affine, sd->ttwu_move_balance);

		}

#endif
@@ -1264,24 +1265,34 @@ void fastcall wake_up_new_task(task_t * p, unsigned long clone_flags) 
			sd = tmp;



	if (sd) {

		int new_cpu;

		struct sched_group *group;



		schedstat_inc(sd, sbf_cnt);

		cpu = task_cpu(p);

		group = find_idlest_group(sd, p, cpu);

		if (group) {

			int new_cpu;

		if (!group) {

			schedstat_inc(sd, sbf_balanced);

			goto no_forkbalance;

		}



		new_cpu = find_idlest_cpu(group, cpu);

			if (new_cpu != -1 && new_cpu != cpu &&

					cpu_isset(new_cpu, p->cpus_allowed)) {

		if (new_cpu == -1 || new_cpu == cpu) {

			schedstat_inc(sd, sbf_balanced);

			goto no_forkbalance;

		}



		if (cpu_isset(new_cpu, p->cpus_allowed)) {

			schedstat_inc(sd, sbf_pushed);

			set_task_cpu(p, new_cpu);

			task_rq_unlock(rq, &flags);

			rq = task_rq_lock(p, &flags);

			cpu = task_cpu(p);

		}

	}

	}

#endif



no_forkbalance:

#endif

	/*

	 * We decrease the sleep average of forking parents

	 * and children as well, to keep max-interactive tasks
@@ -1618,31 +1629,29 @@ void sched_exec(void) 
	struct sched_domain *tmp, *sd = NULL;

	int new_cpu, this_cpu = get_cpu();



	/* Prefer the current CPU if there's only this task running */

	if (this_rq()->nr_running <= 1)

		goto out;



	for_each_domain(this_cpu, tmp)

		if (tmp->flags & SD_BALANCE_EXEC)

			sd = tmp;



	if (sd) {

		struct sched_group *group;

		schedstat_inc(sd, sbe_attempts);

		schedstat_inc(sd, sbe_cnt);

		group = find_idlest_group(sd, current, this_cpu);

		if (!group)

		if (!group) {

			schedstat_inc(sd, sbe_balanced);

			goto out;

		}

		new_cpu = find_idlest_cpu(group, this_cpu);

		if (new_cpu == -1)

		if (new_cpu == -1 || new_cpu == this_cpu) {

			schedstat_inc(sd, sbe_balanced);

			goto out;

		}



		if (new_cpu != this_cpu) {

		schedstat_inc(sd, sbe_pushed);

		put_cpu();

		sched_migrate_task(current, new_cpu);

		return;

	}

	}

out:

	put_cpu();

}