Commit 2509940f authored by Alex Shi's avatar Alex Shi Committed by Ingo Molnar
Browse files

sched/cfs_rq: Change atomic64_t removed_load to atomic_long_t 



Similar to runnable_load_avg, blocked_load_avg variable, long type is
enough for removed_load in 64 bit or 32 bit machine.

Then we avoid the expensive atomic64 operations on 32 bit machine.

Signed-off-by: default avatarAlex Shi <alex.shi@intel.com>
Reviewed-by: default avatarPaul Turner <pjt@google.com>
Tested-by: default avatarVincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: default avatarPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1371694737-29336-12-git-send-email-alex.shi@intel.com


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent bf5b986e

kernel/sched/fair.c

+6 −4
Original line number Diff line number Diff line
@@ -1517,8 +1517,9 @@ static void update_cfs_rq_blocked_load(struct cfs_rq *cfs_rq, int force_update) 
	if (!decays && !force_update)

		return;



	if (atomic64_read(&cfs_rq->removed_load)) {

		u64 removed_load = atomic64_xchg(&cfs_rq->removed_load, 0);

	if (atomic_long_read(&cfs_rq->removed_load)) {

		unsigned long removed_load;

		removed_load = atomic_long_xchg(&cfs_rq->removed_load, 0);

		subtract_blocked_load_contrib(cfs_rq, removed_load);

	}
@@ -3480,7 +3481,8 @@ migrate_task_rq_fair(struct task_struct *p, int next_cpu) 
	 */

	if (se->avg.decay_count) {

		se->avg.decay_count = -__synchronize_entity_decay(se);

		atomic64_add(se->avg.load_avg_contrib, &cfs_rq->removed_load);

		atomic_long_add(se->avg.load_avg_contrib,

						&cfs_rq->removed_load);

	}

}

#endif /* CONFIG_SMP */
@@ -5942,7 +5944,7 @@ void init_cfs_rq(struct cfs_rq *cfs_rq) 
#endif

#ifdef CONFIG_SMP

	atomic64_set(&cfs_rq->decay_counter, 1);

	atomic64_set(&cfs_rq->removed_load, 0);

	atomic_long_set(&cfs_rq->removed_load, 0);

#endif

}

kernel/sched/sched.h

+2 −1
Original line number Diff line number Diff line
@@ -278,8 +278,9 @@ struct cfs_rq { 
	 * the FAIR_GROUP_SCHED case).

	 */

	unsigned long runnable_load_avg, blocked_load_avg;

	atomic64_t decay_counter, removed_load;

	atomic64_t decay_counter;

	u64 last_decay;

	atomic_long_t removed_load;



#ifdef CONFIG_FAIR_GROUP_SCHED

	/* Required to track per-cpu representation of a task_group */