Merge "sched/fair: Fix capacity and nr_run comparisons in can_migrate_task()" (ab832489) · Commits · e / devices / android_kernel_xiaomi_markw

kernel/sched/fair.c

+29 −27

Original line number	Diff line number	Diff line
		@@ -7403,7 +7403,7 @@ static
		int can_migrate_task(struct task_struct p, struct lb_env env)
		{
		int tsk_cache_hot = 0;
		int twf;
		int twf, group_cpus;

		lockdep_assert_held(&env->src_rq->lock);

		@@ -7417,32 +7417,6 @@ int can_migrate_task(struct task_struct p, struct lb_env env)
		if (throttled_lb_pair(task_group(p), env->src_cpu, env->dst_cpu))
		return 0;

		if (nr_big_tasks(env->src_rq) &&
		capacity(env->dst_rq) > capacity(env->src_rq) &&
		!is_big_task(p))
		return 0;

		if (env->flags & LBF_IGNORE_SMALL_TASKS && is_small_task(p))
		return 0;

		twf = task_will_fit(p, env->dst_cpu);

		/*
		* Attempt to not pull tasks that don't fit. We may get lucky and find
		* one that actually fits.
		*/
		if (env->flags & LBF_IGNORE_BIG_TASKS && !twf)
		return 0;

		/*
		* Group imbalance can sometimes cause work to be pulled across groups
		* even though the group could have managed the imbalance on its own.
		* Prevent inter-cluster migrations for big tasks when the number of
		* tasks is lower than the capacity of the group.
		*/
		if (!twf && env->busiest_nr_running <= env->busiest_grp_capacity)
		return 0;

		if (!cpumask_test_cpu(env->dst_cpu, tsk_cpus_allowed(p))) {
		int cpu;

		@@ -7476,6 +7450,34 @@ int can_migrate_task(struct task_struct p, struct lb_env env)
		/* Record that we found atleast one task that could run on dst_cpu */
		env->flags &= ~LBF_ALL_PINNED;

		if (nr_big_tasks(env->src_rq) &&
		capacity(env->dst_rq) > capacity(env->src_rq) &&
		!is_big_task(p))
		return 0;

		if (env->flags & LBF_IGNORE_SMALL_TASKS && is_small_task(p))
		return 0;

		twf = task_will_fit(p, env->dst_cpu);

		/*
		* Attempt to not pull tasks that don't fit. We may get lucky and find
		* one that actually fits.
		*/
		if (env->flags & LBF_IGNORE_BIG_TASKS && !twf)
		return 0;

		/*
		* Group imbalance can sometimes cause work to be pulled across groups
		* even though the group could have managed the imbalance on its own.
		* Prevent inter-cluster migrations for big tasks when the number of
		* tasks is lower than the capacity of the group.
		*/
		group_cpus = DIV_ROUND_UP(env->busiest_grp_capacity,
		SCHED_CAPACITY_SCALE);
		if (!twf && env->busiest_nr_running <= group_cpus)
		return 0;

		if (task_running(env->src_rq, p)) {
		schedstat_inc(p, se.statistics.nr_failed_migrations_running);
		return 0;