sched/deadline: Fix hotplug admission control (de212f18) · Commits · 戴 / test

kernel/sched/core.c

+32 −51

Original line number	Diff line number	Diff line
		@@ -1887,9 +1887,15 @@ inline struct dl_bw *dl_bw_of(int i)
		return &cpu_rq(i)->rd->dl_bw;
		}

		static inline int __dl_span_weight(struct rq *rq)
		static inline int dl_bw_cpus(int i)
		{
		return cpumask_weight(rq->rd->span);
		struct root_domain *rd = cpu_rq(i)->rd;
		int cpus = 0;

		for_each_cpu_and(i, rd->span, cpu_active_mask)
		cpus++;

		return cpus;
		}
		#else
		inline struct dl_bw *dl_bw_of(int i)
		@@ -1897,7 +1903,7 @@ inline struct dl_bw *dl_bw_of(int i)
		return &cpu_rq(i)->dl.dl_bw;
		}

		static inline int __dl_span_weight(struct rq *rq)
		static inline int dl_bw_cpus(int i)
		{
		return 1;
		}
		@@ -1938,8 +1944,7 @@ static int dl_overflow(struct task_struct *p, int policy,
		u64 period = attr->sched_period;
		u64 runtime = attr->sched_runtime;
		u64 new_bw = dl_policy(policy) ? to_ratio(period, runtime) : 0;
		int cpus = __dl_span_weight(task_rq(p));
		int err = -1;
		int cpus, err = -1;

		if (new_bw == p->dl.dl_bw)
		return 0;
		@@ -1950,6 +1955,7 @@ static int dl_overflow(struct task_struct *p, int policy,
		* allocated bandwidth of the container.
		*/
		raw_spin_lock(&dl_b->lock);
		cpus = dl_bw_cpus(task_cpu(p));
		if (dl_policy(policy) && !task_has_dl_policy(p) &&
		!__dl_overflow(dl_b, cpus, 0, new_bw)) {
		__dl_add(dl_b, new_bw);
		@@ -4521,42 +4527,6 @@ out:
		}
		EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr);

		/*
		* When dealing with a -deadline task, we have to check if moving it to
		* a new CPU is possible or not. In fact, this is only true iff there
		* is enough bandwidth available on such CPU, otherwise we want the
		* whole migration procedure to fail over.
		*/
		static inline
		bool set_task_cpu_dl(struct task_struct *p, unsigned int cpu)
		{
		struct dl_bw *dl_b = dl_bw_of(task_cpu(p));
		struct dl_bw *cpu_b = dl_bw_of(cpu);
		int ret = 1;
		u64 bw;

		if (dl_b == cpu_b)
		return 1;

		raw_spin_lock(&dl_b->lock);
		raw_spin_lock(&cpu_b->lock);

		bw = cpu_b->bw * cpumask_weight(cpu_rq(cpu)->rd->span);
		if (dl_bandwidth_enabled() &&
		bw < cpu_b->total_bw + p->dl.dl_bw) {
		ret = 0;
		goto unlock;
		}
		dl_b->total_bw -= p->dl.dl_bw;
		cpu_b->total_bw += p->dl.dl_bw;

		unlock:
		raw_spin_unlock(&cpu_b->lock);
		raw_spin_unlock(&dl_b->lock);

		return ret;
		}

		/*
		* Move (not current) task off this cpu, onto dest cpu. We're doing
		* this because either it can't run here any more (set_cpus_allowed()
		@@ -4588,13 +4558,6 @@ static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu)
		if (!cpumask_test_cpu(dest_cpu, tsk_cpus_allowed(p)))
		goto fail;

		/*
		* If p is -deadline, proceed only if there is enough
		* bandwidth available on dest_cpu
		*/
		if (unlikely(dl_task(p)) && !set_task_cpu_dl(p, dest_cpu))
		goto fail;

		/*
		* If we're not on a rq, the next wake-up will ensure we're
		* placed properly.
		@@ -5052,13 +5015,31 @@ static int sched_cpu_active(struct notifier_block *nfb,
		static int sched_cpu_inactive(struct notifier_block *nfb,
		unsigned long action, void *hcpu)
		{
		unsigned long flags;
		long cpu = (long)hcpu;

		switch (action & ~CPU_TASKS_FROZEN) {
		case CPU_DOWN_PREPARE:
		set_cpu_active((long)hcpu, false);
		set_cpu_active(cpu, false);

		/* explicitly allow suspend */
		if (!(action & CPU_TASKS_FROZEN)) {
		struct dl_bw *dl_b = dl_bw_of(cpu);
		bool overflow;
		int cpus;

		raw_spin_lock_irqsave(&dl_b->lock, flags);
		cpus = dl_bw_cpus(cpu);
		overflow = __dl_overflow(dl_b, cpus, 0, 0);
		raw_spin_unlock_irqrestore(&dl_b->lock, flags);

		if (overflow)
		return notifier_from_errno(-EBUSY);
		}
		return NOTIFY_OK;
		default:
		return NOTIFY_DONE;
		}

		return NOTIFY_DONE;
		}

		static int __init migration_init(void)

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