Merge "sched/fair: Avoid force newly idle load balance if have iowait task" (6ffbb5b0) · Commits · e / devices / android_kernel_oneplus_sm7250

kernel/sched/fair.c

+20 −3

Original line number	Diff line number	Diff line
		@@ -11549,6 +11549,20 @@ static inline bool nohz_idle_balance(struct rq *this_rq, enum cpu_idle_type idle
		static inline void nohz_newidle_balance(struct rq *this_rq) { }
		#endif /* CONFIG_NO_HZ_COMMON */

		static bool silver_has_big_tasks(void)
		{
		int cpu;

		for_each_possible_cpu(cpu) {
		if (!is_min_capacity_cpu(cpu))
		break;
		if (cpu_rq(cpu)->walt_stats.nr_big_tasks)
		return true;
		}

		return false;
		}

		/*
		* idle_balance is called by schedule() if this_cpu is about to become
		* idle. Attempts to pull tasks from other CPUs.
		@@ -11560,6 +11574,7 @@ static int idle_balance(struct rq this_rq, struct rq_flags rf)
		struct sched_domain *sd;
		int pulled_task = 0;
		u64 curr_cost = 0;
		u64 avg_idle = this_rq->avg_idle;

		if (cpu_isolated(this_cpu))
		return 0;
		@@ -11575,7 +11590,9 @@ static int idle_balance(struct rq this_rq, struct rq_flags rf)
		*/
		if (!cpu_active(this_cpu))
		return 0;

		if (!is_min_capacity_cpu(this_cpu) && silver_has_big_tasks()
		&& (atomic_read(&this_rq->nr_iowait) == 0))
		avg_idle = ULLONG_MAX;
		/*
		* This is OK, because current is on_cpu, which avoids it being picked
		* for load-balance and preemption/IRQs are still disabled avoiding
		@@ -11584,7 +11601,7 @@ static int idle_balance(struct rq this_rq, struct rq_flags rf)
		*/
		rq_unpin_lock(this_rq, rf);

		if (this_rq->avg_idle < sysctl_sched_migration_cost \|\|
		if (avg_idle < sysctl_sched_migration_cost \|\|
		!READ_ONCE(this_rq->rd->overload)) {

		rcu_read_lock();
		@@ -11609,7 +11626,7 @@ static int idle_balance(struct rq this_rq, struct rq_flags rf)
		if (!(sd->flags & SD_LOAD_BALANCE))
		continue;

		if (this_rq->avg_idle < curr_cost + sd->max_newidle_lb_cost) {
		if (avg_idle < curr_cost + sd->max_newidle_lb_cost) {
		update_next_balance(sd, &next_balance);
		break;
		}