sched: Rework CPU hotplug task selection (10e7071b) · Commits · 戴 / test

kernel/sched/core.c

+14 −18

Original line number	Diff line number	Diff line
		@@ -6082,21 +6082,22 @@ static void calc_load_migrate(struct rq *rq)
		atomic_long_add(delta, &calc_load_tasks);
		}

		static void put_prev_task_fake(struct rq rq, struct task_struct prev)
		static struct task_struct __pick_migrate_task(struct rq rq)
		{
		}
		const struct sched_class *class;
		struct task_struct *next;

		static const struct sched_class fake_sched_class = {
		.put_prev_task = put_prev_task_fake,
		};
		for_each_class(class) {
		next = class->pick_next_task(rq, NULL, NULL);
		if (next) {
		next->sched_class->put_prev_task(rq, next);
		return next;
		}
		}

		static struct task_struct fake_task = {
		/*
		* Avoid pull_{rt,dl}_task()
		*/
		.prio = MAX_PRIO + 1,
		.sched_class = &fake_sched_class,
		};
		/* The idle class should always have a runnable task */
		BUG();
		}

		/*
		* Migrate all tasks from the rq, sleeping tasks will be migrated by
		@@ -6139,12 +6140,7 @@ static void migrate_tasks(struct rq dead_rq, struct rq_flags rf)
		if (rq->nr_running == 1)
		break;

		/*
		* pick_next_task() assumes pinned rq->lock:
		*/
		next = pick_next_task(rq, &fake_task, rf);
		BUG_ON(!next);
		put_prev_task(rq, next);
		next = __pick_migrate_task(rq);

		/*
		* Rules for changing task_struct::cpus_mask are holding

+1 −0

Original line number	Diff line number	Diff line
		@@ -1751,6 +1751,7 @@ struct sched_class {

		static inline void put_prev_task(struct rq rq, struct task_struct prev)
		{
		WARN_ON_ONCE(rq->curr != prev);
		prev->sched_class->put_prev_task(rq, prev);
		}