Commit 0ac1ee9e authored by K Prateek Nayak's avatar K Prateek Nayak Committed by Peter Zijlstra
Browse files

sched/fair: Do not compute NUMA Balancing stats unnecessarily during lb 



Aggregate nr_numa_running and nr_preferred_running when load balancing
at NUMA domains only. While at it, also move the aggregation below the
idle_cpu() check since an idle CPU cannot have any preferred tasks.

Signed-off-by: default avatarK Prateek Nayak <kprateek.nayak@amd.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: default avatarShrikanth Hegde <sshegde@linux.ibm.com>
Reviewed-by: default avatarVincent Guittot <vincent.guittot@linaro.org>
Link: https://lore.kernel.org/r/20241223043407.1611-7-kprateek.nayak@amd.com
parent e1bc0264

kernel/sched/fair.c

+9 −6
Original line number Diff line number Diff line
@@ -10409,7 +10409,7 @@ static inline void update_sg_lb_stats(struct lb_env *env, 
				      bool *sg_overloaded,

				      bool *sg_overutilized)

{

	int i, nr_running, local_group;

	int i, nr_running, local_group, sd_flags = env->sd->flags;



	memset(sgs, 0, sizeof(*sgs));
@@ -10433,10 +10433,6 @@ static inline void update_sg_lb_stats(struct lb_env *env, 
		if (cpu_overutilized(i))

			*sg_overutilized = 1;



#ifdef CONFIG_NUMA_BALANCING

		sgs->nr_numa_running += rq->nr_numa_running;

		sgs->nr_preferred_running += rq->nr_preferred_running;

#endif

		/*

		 * No need to call idle_cpu() if nr_running is not 0

		 */
@@ -10446,10 +10442,17 @@ static inline void update_sg_lb_stats(struct lb_env *env, 
			continue;

		}



#ifdef CONFIG_NUMA_BALANCING

		/* Only fbq_classify_group() uses this to classify NUMA groups */

		if (sd_flags & SD_NUMA) {

			sgs->nr_numa_running += rq->nr_numa_running;

			sgs->nr_preferred_running += rq->nr_preferred_running;

		}

#endif

		if (local_group)

			continue;



		if (env->sd->flags & SD_ASYM_CPUCAPACITY) {

		if (sd_flags & SD_ASYM_CPUCAPACITY) {

			/* Check for a misfit task on the cpu */

			if (sgs->group_misfit_task_load < rq->misfit_task_load) {

				sgs->group_misfit_task_load = rq->misfit_task_load;