Merge "sched: Fix race condition with active balance" (b820fbcd) · Commits · e / devices / android_kernel_sony_msm8998

kernel/sched/core.c

+9 −5

Original line number	Diff line number	Diff line
		@@ -1912,7 +1912,7 @@ void scheduler_ipi(void)
		/*
		* Check if someone kicked us for doing the nohz idle load balance.
		*/
		if (unlikely(got_nohz_idle_kick())) {
		if (unlikely(got_nohz_idle_kick()) && !cpu_isolated(cpu)) {
		this_rq()->idle_balance = 1;
		raise_softirq_irqoff(SCHED_SOFTIRQ);
		}
		@@ -5562,7 +5562,6 @@ static void set_rq_offline(struct rq *rq);

		int do_isolation_work_cpu_stop(void *data)
		{
		unsigned long flags;
		unsigned int cpu = smp_processor_id();
		struct rq *rq = cpu_rq(cpu);

		@@ -5570,9 +5569,12 @@ int do_isolation_work_cpu_stop(void *data)

		irq_migrate_all_off_this_cpu();

		local_irq_disable();

		sched_ttwu_pending();

		/* Update our root-domain */
		raw_spin_lock_irqsave(&rq->lock, flags);
		raw_spin_lock(&rq->lock);

		if (rq->rd) {
		BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span));
		@@ -5580,13 +5582,16 @@ int do_isolation_work_cpu_stop(void *data)
		}

		migrate_tasks(rq, false);
		raw_spin_unlock_irqrestore(&rq->lock, flags);
		raw_spin_unlock(&rq->lock);

		/*
		* We might have been in tickless state. Clear NOHZ flags to avoid
		* us being kicked for helping out with balancing
		*/
		nohz_balance_clear_nohz_mask(cpu);

		clear_hmp_request(cpu);
		local_irq_enable();
		return 0;
		}

		@@ -5695,7 +5700,6 @@ int sched_isolate_cpu(int cpu)
		migrate_sync_cpu(cpu, cpumask_first(&avail_cpus));
		stop_cpus(cpumask_of(cpu), do_isolation_work_cpu_stop, 0);

		clear_hmp_request(cpu);
		calc_load_migrate(rq);
		update_max_interval();
		sched_update_group_capacities(cpu);

kernel/sched/fair.c

+22 −5

Original line number	Diff line number	Diff line
		@@ -8121,8 +8121,11 @@ static struct rq find_busiest_queue_hmp(struct lb_env env,
		int max_nr_big = 0, nr_big;
		bool find_big = !!(env->flags & LBF_BIG_TASK_ACTIVE_BALANCE);
		int i;
		cpumask_t cpus;

		for_each_cpu(i, sched_group_cpus(group)) {
		cpumask_andnot(&cpus, sched_group_cpus(group), cpu_isolated_mask);

		for_each_cpu(i, &cpus) {
		struct rq *rq = cpu_rq(i);
		u64 cumulative_runnable_avg =
		rq->hmp_stats.cumulative_runnable_avg;
		@@ -8285,6 +8288,15 @@ static int need_active_balance(struct lb_env *env)
		sd->cache_nice_tries + NEED_ACTIVE_BALANCE_THRESHOLD);
		}

		static int group_balance_cpu_not_isolated(struct sched_group *sg)
		{
		cpumask_t cpus;

		cpumask_and(&cpus, sched_group_cpus(sg), sched_group_mask(sg));
		cpumask_andnot(&cpus, &cpus, cpu_isolated_mask);
		return cpumask_first(&cpus);
		}

		static int should_we_balance(struct lb_env *env)
		{
		struct sched_group *sg = env->sd->groups;
		@@ -8302,7 +8314,8 @@ static int should_we_balance(struct lb_env *env)
		sg_mask = sched_group_mask(sg);
		/* Try to find first idle cpu */
		for_each_cpu_and(cpu, sg_cpus, env->cpus) {
		if (!cpumask_test_cpu(cpu, sg_mask) \|\| !idle_cpu(cpu))
		if (!cpumask_test_cpu(cpu, sg_mask) \|\| !idle_cpu(cpu) \|\|
		cpu_isolated(cpu))
		continue;

		balance_cpu = cpu;
		@@ -8310,7 +8323,7 @@ static int should_we_balance(struct lb_env *env)
		}

		if (balance_cpu == -1)
		balance_cpu = group_balance_cpu(sg);
		balance_cpu = group_balance_cpu_not_isolated(sg);

		/*
		* First idle cpu or the first cpu(busiest) in this sched group
		@@ -8530,7 +8543,8 @@ no_move:
		* ->active_balance_work. Once set, it's cleared
		* only after active load balance is finished.
		*/
		if (!busiest->active_balance) {
		if (!busiest->active_balance &&
		!cpu_isolated(cpu_of(busiest))) {
		busiest->active_balance = 1;
		busiest->push_cpu = this_cpu;
		active_balance = 1;
		@@ -9198,12 +9212,15 @@ static void nohz_idle_balance(struct rq *this_rq, enum cpu_idle_type idle)
		/* Earliest time when we have to do rebalance again */
		unsigned long next_balance = jiffies + 60*HZ;
		int update_next_balance = 0;
		cpumask_t cpus;

		if (idle != CPU_IDLE \|\|
		!test_bit(NOHZ_BALANCE_KICK, nohz_flags(this_cpu)))
		goto end;

		for_each_cpu(balance_cpu, nohz.idle_cpus_mask) {
		cpumask_andnot(&cpus, nohz.idle_cpus_mask, cpu_isolated_mask);

		for_each_cpu(balance_cpu, &cpus) {
		if (balance_cpu == this_cpu \|\| !idle_cpu(balance_cpu))
		continue;