Commit 06a76fe0 authored by Nicolas Pitre's avatar Nicolas Pitre Committed by Ingo Molnar
Browse files

sched/deadline: Move DL related code from sched/core.c to sched/deadline.c 



This helps making sched/core.c smaller and hopefully easier to understand and maintain.

Signed-off-by: default avatarNicolas Pitre <nico@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170621182203.30626-2-nicolas.pitre@linaro.org


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent e1d4eeec

kernel/sched/core.c

+6 −337
Original line number Diff line number Diff line
@@ -2139,25 +2139,6 @@ int wake_up_state(struct task_struct *p, unsigned int state) 
	return try_to_wake_up(p, state, 0);

}



/*

 * This function clears the sched_dl_entity static params.

 */

void __dl_clear_params(struct task_struct *p)

{

	struct sched_dl_entity *dl_se = &p->dl;



	dl_se->dl_runtime = 0;

	dl_se->dl_deadline = 0;

	dl_se->dl_period = 0;

	dl_se->flags = 0;

	dl_se->dl_bw = 0;

	dl_se->dl_density = 0;



	dl_se->dl_throttled = 0;

	dl_se->dl_yielded = 0;

	dl_se->dl_non_contending = 0;

}



/*

 * Perform scheduler related setup for a newly forked process p.

 * p is forked by current.
@@ -2438,101 +2419,6 @@ unsigned long to_ratio(u64 period, u64 runtime) 
	return div64_u64(runtime << BW_SHIFT, period);

}



#ifdef CONFIG_SMP

inline struct dl_bw *dl_bw_of(int i)

{

	RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held(),

			 "sched RCU must be held");

	return &cpu_rq(i)->rd->dl_bw;

}



inline int dl_bw_cpus(int i)

{

	struct root_domain *rd = cpu_rq(i)->rd;

	int cpus = 0;



	RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held(),

			 "sched RCU must be held");

	for_each_cpu_and(i, rd->span, cpu_active_mask)

		cpus++;



	return cpus;

}

#else

inline struct dl_bw *dl_bw_of(int i)

{

	return &cpu_rq(i)->dl.dl_bw;

}



inline int dl_bw_cpus(int i)

{

	return 1;

}

#endif



/*

 * We must be sure that accepting a new task (or allowing changing the

 * parameters of an existing one) is consistent with the bandwidth

 * constraints. If yes, this function also accordingly updates the currently

 * allocated bandwidth to reflect the new situation.

 *

 * This function is called while holding p's rq->lock.

 */

static int dl_overflow(struct task_struct *p, int policy,

		       const struct sched_attr *attr)

{



	struct dl_bw *dl_b = dl_bw_of(task_cpu(p));

	u64 period = attr->sched_period ?: attr->sched_deadline;

	u64 runtime = attr->sched_runtime;

	u64 new_bw = dl_policy(policy) ? to_ratio(period, runtime) : 0;

	int cpus, err = -1;



	/* !deadline task may carry old deadline bandwidth */

	if (new_bw == p->dl.dl_bw && task_has_dl_policy(p))

		return 0;



	/*

	 * Either if a task, enters, leave, or stays -deadline but changes

	 * its parameters, we may need to update accordingly the total

	 * 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)) {

		if (hrtimer_active(&p->dl.inactive_timer))

			__dl_clear(dl_b, p->dl.dl_bw, cpus);

		__dl_add(dl_b, new_bw, cpus);

		err = 0;

	} else if (dl_policy(policy) && task_has_dl_policy(p) &&

		   !__dl_overflow(dl_b, cpus, p->dl.dl_bw, new_bw)) {

		/*

		 * XXX this is slightly incorrect: when the task

		 * utilization decreases, we should delay the total

		 * utilization change until the task's 0-lag point.

		 * But this would require to set the task's "inactive

		 * timer" when the task is not inactive.

		 */

		__dl_clear(dl_b, p->dl.dl_bw, cpus);

		__dl_add(dl_b, new_bw, cpus);

		dl_change_utilization(p, new_bw);

		err = 0;

	} else if (!dl_policy(policy) && task_has_dl_policy(p)) {

		/*

		 * Do not decrease the total deadline utilization here,

		 * switched_from_dl() will take care to do it at the correct

		 * (0-lag) time.

		 */

		err = 0;

	}

	raw_spin_unlock(&dl_b->lock);



	return err;

}



extern void init_dl_bw(struct dl_bw *dl_b);



/*

 * wake_up_new_task - wake up a newly created task for the first time.

 *
@@ -4014,27 +3900,6 @@ static struct task_struct *find_process_by_pid(pid_t pid) 
	return pid ? find_task_by_vpid(pid) : current;

}



/*

 * This function initializes the sched_dl_entity of a newly becoming

 * SCHED_DEADLINE task.

 *

 * Only the static values are considered here, the actual runtime and the

 * absolute deadline will be properly calculated when the task is enqueued

 * for the first time with its new policy.

 */

static void

__setparam_dl(struct task_struct *p, const struct sched_attr *attr)

{

	struct sched_dl_entity *dl_se = &p->dl;



	dl_se->dl_runtime = attr->sched_runtime;

	dl_se->dl_deadline = attr->sched_deadline;

	dl_se->dl_period = attr->sched_period ?: dl_se->dl_deadline;

	dl_se->flags = attr->sched_flags;

	dl_se->dl_bw = to_ratio(dl_se->dl_period, dl_se->dl_runtime);

	dl_se->dl_density = to_ratio(dl_se->dl_deadline, dl_se->dl_runtime);

}



/*

 * sched_setparam() passes in -1 for its policy, to let the functions

 * it calls know not to change it.
@@ -4088,59 +3953,6 @@ static void __setscheduler(struct rq *rq, struct task_struct *p, 
		p->sched_class = &fair_sched_class;

}



static void

__getparam_dl(struct task_struct *p, struct sched_attr *attr)

{

	struct sched_dl_entity *dl_se = &p->dl;



	attr->sched_priority = p->rt_priority;

	attr->sched_runtime = dl_se->dl_runtime;

	attr->sched_deadline = dl_se->dl_deadline;

	attr->sched_period = dl_se->dl_period;

	attr->sched_flags = dl_se->flags;

}



/*

 * This function validates the new parameters of a -deadline task.

 * We ask for the deadline not being zero, and greater or equal

 * than the runtime, as well as the period of being zero or

 * greater than deadline. Furthermore, we have to be sure that

 * user parameters are above the internal resolution of 1us (we

 * check sched_runtime only since it is always the smaller one) and

 * below 2^63 ns (we have to check both sched_deadline and

 * sched_period, as the latter can be zero).

 */

static bool

__checkparam_dl(const struct sched_attr *attr)

{

	/* deadline != 0 */

	if (attr->sched_deadline == 0)

		return false;



	/*

	 * Since we truncate DL_SCALE bits, make sure we're at least

	 * that big.

	 */

	if (attr->sched_runtime < (1ULL << DL_SCALE))

		return false;



	/*

	 * Since we use the MSB for wrap-around and sign issues, make

	 * sure it's not set (mind that period can be equal to zero).

	 */

	if (attr->sched_deadline & (1ULL << 63) ||

	    attr->sched_period & (1ULL << 63))

		return false;



	/* runtime <= deadline <= period (if period != 0) */

	if ((attr->sched_period != 0 &&

	     attr->sched_period < attr->sched_deadline) ||

	    attr->sched_deadline < attr->sched_runtime)

		return false;



	return true;

}



/*

 * Check the target process has a UID that matches the current process's:

 */
@@ -4157,19 +3969,6 @@ static bool check_same_owner(struct task_struct *p) 
	return match;

}



static bool dl_param_changed(struct task_struct *p, const struct sched_attr *attr)

{

	struct sched_dl_entity *dl_se = &p->dl;



	if (dl_se->dl_runtime != attr->sched_runtime ||

		dl_se->dl_deadline != attr->sched_deadline ||

		dl_se->dl_period != attr->sched_period ||

		dl_se->flags != attr->sched_flags)

		return true;



	return false;

}



static int __sched_setscheduler(struct task_struct *p,

				const struct sched_attr *attr,

				bool user, bool pi)
@@ -4350,7 +4149,7 @@ change: 
	 * of a SCHED_DEADLINE task) we need to check if enough bandwidth

	 * is available.

	 */

	if ((dl_policy(policy) || dl_task(p)) && dl_overflow(p, policy, attr)) {

	if ((dl_policy(policy) || dl_task(p)) && sched_dl_overflow(p, policy, attr)) {

		task_rq_unlock(rq, p, &rf);

		return -EBUSY;

	}
@@ -5456,23 +5255,12 @@ void init_idle(struct task_struct *idle, int cpu) 
int cpuset_cpumask_can_shrink(const struct cpumask *cur,

			      const struct cpumask *trial)

{

	int ret = 1, trial_cpus;

	struct dl_bw *cur_dl_b;

	unsigned long flags;

	int ret = 1;



	if (!cpumask_weight(cur))

		return ret;



	rcu_read_lock_sched();

	cur_dl_b = dl_bw_of(cpumask_any(cur));

	trial_cpus = cpumask_weight(trial);



	raw_spin_lock_irqsave(&cur_dl_b->lock, flags);

	if (cur_dl_b->bw != -1 &&

	    cur_dl_b->bw * trial_cpus < cur_dl_b->total_bw)

		ret = 0;

	raw_spin_unlock_irqrestore(&cur_dl_b->lock, flags);

	rcu_read_unlock_sched();

	ret = dl_cpuset_cpumask_can_shrink(cur, trial);



	return ret;

}
@@ -5497,34 +5285,8 @@ int task_can_attach(struct task_struct *p, 
	}



	if (dl_task(p) && !cpumask_intersects(task_rq(p)->rd->span,

					      cs_cpus_allowed)) {

		unsigned int dest_cpu = cpumask_any_and(cpu_active_mask,

							cs_cpus_allowed);

		struct dl_bw *dl_b;

		bool overflow;

		int cpus;

		unsigned long flags;



		rcu_read_lock_sched();

		dl_b = dl_bw_of(dest_cpu);

		raw_spin_lock_irqsave(&dl_b->lock, flags);

		cpus = dl_bw_cpus(dest_cpu);

		overflow = __dl_overflow(dl_b, cpus, 0, p->dl.dl_bw);

		if (overflow)

			ret = -EBUSY;

		else {

			/*

			 * We reserve space for this task in the destination

			 * root_domain, as we can't fail after this point.

			 * We will free resources in the source root_domain

			 * later on (see set_cpus_allowed_dl()).

			 */

			__dl_add(dl_b, p->dl.dl_bw, cpus);

		}

		raw_spin_unlock_irqrestore(&dl_b->lock, flags);

		rcu_read_unlock_sched();



	}

					      cs_cpus_allowed))

		ret = dl_task_can_attach(p, cs_cpus_allowed);



out:

	return ret;
@@ -5792,23 +5554,8 @@ static void cpuset_cpu_active(void) 


static int cpuset_cpu_inactive(unsigned int cpu)

{

	unsigned long flags;

	struct dl_bw *dl_b;

	bool overflow;

	int cpus;



	if (!cpuhp_tasks_frozen) {

		rcu_read_lock_sched();

		dl_b = dl_bw_of(cpu);



		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);



		rcu_read_unlock_sched();



		if (overflow)

		if (dl_cpu_busy(cpu))

			return -EBUSY;

		cpuset_update_active_cpus();

	} else {
@@ -6711,84 +6458,6 @@ static int sched_rt_global_constraints(void) 
}

#endif /* CONFIG_RT_GROUP_SCHED */



static int sched_dl_global_validate(void)

{

	u64 runtime = global_rt_runtime();

	u64 period = global_rt_period();

	u64 new_bw = to_ratio(period, runtime);

	struct dl_bw *dl_b;

	int cpu, ret = 0;

	unsigned long flags;



	/*

	 * Here we want to check the bandwidth not being set to some

	 * value smaller than the currently allocated bandwidth in

	 * any of the root_domains.

	 *

	 * FIXME: Cycling on all the CPUs is overdoing, but simpler than

	 * cycling on root_domains... Discussion on different/better

	 * solutions is welcome!

	 */

	for_each_possible_cpu(cpu) {

		rcu_read_lock_sched();

		dl_b = dl_bw_of(cpu);



		raw_spin_lock_irqsave(&dl_b->lock, flags);

		if (new_bw < dl_b->total_bw)

			ret = -EBUSY;

		raw_spin_unlock_irqrestore(&dl_b->lock, flags);



		rcu_read_unlock_sched();



		if (ret)

			break;

	}



	return ret;

}



void init_dl_rq_bw_ratio(struct dl_rq *dl_rq)

{

	if (global_rt_runtime() == RUNTIME_INF) {

		dl_rq->bw_ratio = 1 << RATIO_SHIFT;

		dl_rq->extra_bw = 1 << BW_SHIFT;

	} else {

		dl_rq->bw_ratio = to_ratio(global_rt_runtime(),

			  global_rt_period()) >> (BW_SHIFT - RATIO_SHIFT);

		dl_rq->extra_bw = to_ratio(global_rt_period(),

						    global_rt_runtime());

	}

}



static void sched_dl_do_global(void)

{

	u64 new_bw = -1;

	struct dl_bw *dl_b;

	int cpu;

	unsigned long flags;



	def_dl_bandwidth.dl_period = global_rt_period();

	def_dl_bandwidth.dl_runtime = global_rt_runtime();



	if (global_rt_runtime() != RUNTIME_INF)

		new_bw = to_ratio(global_rt_period(), global_rt_runtime());



	/*

	 * FIXME: As above...

	 */

	for_each_possible_cpu(cpu) {

		rcu_read_lock_sched();

		dl_b = dl_bw_of(cpu);



		raw_spin_lock_irqsave(&dl_b->lock, flags);

		dl_b->bw = new_bw;

		raw_spin_unlock_irqrestore(&dl_b->lock, flags);



		rcu_read_unlock_sched();

		init_dl_rq_bw_ratio(&cpu_rq(cpu)->dl);

	}

}



static int sched_rt_global_validate(void)

{

	if (sysctl_sched_rt_period <= 0)

kernel/sched/deadline.c

+344 −0
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ 
#include "sched.h"



#include <linux/slab.h>

#include <uapi/linux/sched/types.h>



struct dl_bandwidth def_dl_bandwidth;
@@ -43,6 +44,38 @@ static inline int on_dl_rq(struct sched_dl_entity *dl_se) 
	return !RB_EMPTY_NODE(&dl_se->rb_node);

}



#ifdef CONFIG_SMP

static inline struct dl_bw *dl_bw_of(int i)

{

	RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held(),

			 "sched RCU must be held");

	return &cpu_rq(i)->rd->dl_bw;

}



static inline int dl_bw_cpus(int i)

{

	struct root_domain *rd = cpu_rq(i)->rd;

	int cpus = 0;



	RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held(),

			 "sched RCU must be held");

	for_each_cpu_and(i, rd->span, cpu_active_mask)

		cpus++;



	return cpus;

}

#else

static inline struct dl_bw *dl_bw_of(int i)

{

	return &cpu_rq(i)->dl.dl_bw;

}



static inline int dl_bw_cpus(int i)

{

	return 1;

}

#endif



static inline

void add_running_bw(u64 dl_bw, struct dl_rq *dl_rq)

{
@@ -2318,6 +2351,317 @@ const struct sched_class dl_sched_class = { 
	.update_curr		= update_curr_dl,

};



int sched_dl_global_validate(void)

{

	u64 runtime = global_rt_runtime();

	u64 period = global_rt_period();

	u64 new_bw = to_ratio(period, runtime);

	struct dl_bw *dl_b;

	int cpu, ret = 0;

	unsigned long flags;



	/*

	 * Here we want to check the bandwidth not being set to some

	 * value smaller than the currently allocated bandwidth in

	 * any of the root_domains.

	 *

	 * FIXME: Cycling on all the CPUs is overdoing, but simpler than

	 * cycling on root_domains... Discussion on different/better

	 * solutions is welcome!

	 */

	for_each_possible_cpu(cpu) {

		rcu_read_lock_sched();

		dl_b = dl_bw_of(cpu);



		raw_spin_lock_irqsave(&dl_b->lock, flags);

		if (new_bw < dl_b->total_bw)

			ret = -EBUSY;

		raw_spin_unlock_irqrestore(&dl_b->lock, flags);



		rcu_read_unlock_sched();



		if (ret)

			break;

	}



	return ret;

}



void init_dl_rq_bw_ratio(struct dl_rq *dl_rq)

{

	if (global_rt_runtime() == RUNTIME_INF) {

		dl_rq->bw_ratio = 1 << RATIO_SHIFT;

		dl_rq->extra_bw = 1 << BW_SHIFT;

	} else {

		dl_rq->bw_ratio = to_ratio(global_rt_runtime(),

			  global_rt_period()) >> (BW_SHIFT - RATIO_SHIFT);

		dl_rq->extra_bw = to_ratio(global_rt_period(),

						    global_rt_runtime());

	}

}



void sched_dl_do_global(void)

{

	u64 new_bw = -1;

	struct dl_bw *dl_b;

	int cpu;

	unsigned long flags;



	def_dl_bandwidth.dl_period = global_rt_period();

	def_dl_bandwidth.dl_runtime = global_rt_runtime();



	if (global_rt_runtime() != RUNTIME_INF)

		new_bw = to_ratio(global_rt_period(), global_rt_runtime());



	/*

	 * FIXME: As above...

	 */

	for_each_possible_cpu(cpu) {

		rcu_read_lock_sched();

		dl_b = dl_bw_of(cpu);



		raw_spin_lock_irqsave(&dl_b->lock, flags);

		dl_b->bw = new_bw;

		raw_spin_unlock_irqrestore(&dl_b->lock, flags);



		rcu_read_unlock_sched();

		init_dl_rq_bw_ratio(&cpu_rq(cpu)->dl);

	}

}



/*

 * We must be sure that accepting a new task (or allowing changing the

 * parameters of an existing one) is consistent with the bandwidth

 * constraints. If yes, this function also accordingly updates the currently

 * allocated bandwidth to reflect the new situation.

 *

 * This function is called while holding p's rq->lock.

 */

int sched_dl_overflow(struct task_struct *p, int policy,

		      const struct sched_attr *attr)

{

	struct dl_bw *dl_b = dl_bw_of(task_cpu(p));

	u64 period = attr->sched_period ?: attr->sched_deadline;

	u64 runtime = attr->sched_runtime;

	u64 new_bw = dl_policy(policy) ? to_ratio(period, runtime) : 0;

	int cpus, err = -1;



	/* !deadline task may carry old deadline bandwidth */

	if (new_bw == p->dl.dl_bw && task_has_dl_policy(p))

		return 0;



	/*

	 * Either if a task, enters, leave, or stays -deadline but changes

	 * its parameters, we may need to update accordingly the total

	 * 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)) {

		if (hrtimer_active(&p->dl.inactive_timer))

			__dl_clear(dl_b, p->dl.dl_bw, cpus);

		__dl_add(dl_b, new_bw, cpus);

		err = 0;

	} else if (dl_policy(policy) && task_has_dl_policy(p) &&

		   !__dl_overflow(dl_b, cpus, p->dl.dl_bw, new_bw)) {

		/*

		 * XXX this is slightly incorrect: when the task

		 * utilization decreases, we should delay the total

		 * utilization change until the task's 0-lag point.

		 * But this would require to set the task's "inactive

		 * timer" when the task is not inactive.

		 */

		__dl_clear(dl_b, p->dl.dl_bw, cpus);

		__dl_add(dl_b, new_bw, cpus);

		dl_change_utilization(p, new_bw);

		err = 0;

	} else if (!dl_policy(policy) && task_has_dl_policy(p)) {

		/*

		 * Do not decrease the total deadline utilization here,

		 * switched_from_dl() will take care to do it at the correct

		 * (0-lag) time.

		 */

		err = 0;

	}

	raw_spin_unlock(&dl_b->lock);



	return err;

}



/*

 * This function initializes the sched_dl_entity of a newly becoming

 * SCHED_DEADLINE task.

 *

 * Only the static values are considered here, the actual runtime and the

 * absolute deadline will be properly calculated when the task is enqueued

 * for the first time with its new policy.

 */

void __setparam_dl(struct task_struct *p, const struct sched_attr *attr)

{

	struct sched_dl_entity *dl_se = &p->dl;



	dl_se->dl_runtime = attr->sched_runtime;

	dl_se->dl_deadline = attr->sched_deadline;

	dl_se->dl_period = attr->sched_period ?: dl_se->dl_deadline;

	dl_se->flags = attr->sched_flags;

	dl_se->dl_bw = to_ratio(dl_se->dl_period, dl_se->dl_runtime);

	dl_se->dl_density = to_ratio(dl_se->dl_deadline, dl_se->dl_runtime);

}



void __getparam_dl(struct task_struct *p, struct sched_attr *attr)

{

	struct sched_dl_entity *dl_se = &p->dl;



	attr->sched_priority = p->rt_priority;

	attr->sched_runtime = dl_se->dl_runtime;

	attr->sched_deadline = dl_se->dl_deadline;

	attr->sched_period = dl_se->dl_period;

	attr->sched_flags = dl_se->flags;

}



/*

 * This function validates the new parameters of a -deadline task.

 * We ask for the deadline not being zero, and greater or equal

 * than the runtime, as well as the period of being zero or

 * greater than deadline. Furthermore, we have to be sure that

 * user parameters are above the internal resolution of 1us (we

 * check sched_runtime only since it is always the smaller one) and

 * below 2^63 ns (we have to check both sched_deadline and

 * sched_period, as the latter can be zero).

 */

bool __checkparam_dl(const struct sched_attr *attr)

{

	/* deadline != 0 */

	if (attr->sched_deadline == 0)

		return false;



	/*

	 * Since we truncate DL_SCALE bits, make sure we're at least

	 * that big.

	 */

	if (attr->sched_runtime < (1ULL << DL_SCALE))

		return false;



	/*

	 * Since we use the MSB for wrap-around and sign issues, make

	 * sure it's not set (mind that period can be equal to zero).

	 */

	if (attr->sched_deadline & (1ULL << 63) ||

	    attr->sched_period & (1ULL << 63))

		return false;



	/* runtime <= deadline <= period (if period != 0) */

	if ((attr->sched_period != 0 &&

	     attr->sched_period < attr->sched_deadline) ||

	    attr->sched_deadline < attr->sched_runtime)

		return false;



	return true;

}



/*

 * This function clears the sched_dl_entity static params.

 */

void __dl_clear_params(struct task_struct *p)

{

	struct sched_dl_entity *dl_se = &p->dl;



	dl_se->dl_runtime = 0;

	dl_se->dl_deadline = 0;

	dl_se->dl_period = 0;

	dl_se->flags = 0;

	dl_se->dl_bw = 0;

	dl_se->dl_density = 0;



	dl_se->dl_throttled = 0;

	dl_se->dl_yielded = 0;

	dl_se->dl_non_contending = 0;

}



bool dl_param_changed(struct task_struct *p, const struct sched_attr *attr)

{

	struct sched_dl_entity *dl_se = &p->dl;



	if (dl_se->dl_runtime != attr->sched_runtime ||

	    dl_se->dl_deadline != attr->sched_deadline ||

	    dl_se->dl_period != attr->sched_period ||

	    dl_se->flags != attr->sched_flags)

		return true;



	return false;

}



#ifdef CONFIG_SMP

int dl_task_can_attach(struct task_struct *p, const struct cpumask *cs_cpus_allowed)

{

	unsigned int dest_cpu = cpumask_any_and(cpu_active_mask,

							cs_cpus_allowed);

	struct dl_bw *dl_b;

	bool overflow;

	int cpus, ret;

	unsigned long flags;



	rcu_read_lock_sched();

	dl_b = dl_bw_of(dest_cpu);

	raw_spin_lock_irqsave(&dl_b->lock, flags);

	cpus = dl_bw_cpus(dest_cpu);

	overflow = __dl_overflow(dl_b, cpus, 0, p->dl.dl_bw);

	if (overflow)

		ret = -EBUSY;

	else {

		/*

		 * We reserve space for this task in the destination

		 * root_domain, as we can't fail after this point.

		 * We will free resources in the source root_domain

		 * later on (see set_cpus_allowed_dl()).

		 */

		__dl_add(dl_b, p->dl.dl_bw, cpus);

		ret = 0;

	}

	raw_spin_unlock_irqrestore(&dl_b->lock, flags);

	rcu_read_unlock_sched();

	return ret;

}



int dl_cpuset_cpumask_can_shrink(const struct cpumask *cur,

				 const struct cpumask *trial)

{

	int ret = 1, trial_cpus;

	struct dl_bw *cur_dl_b;

	unsigned long flags;



	rcu_read_lock_sched();

	cur_dl_b = dl_bw_of(cpumask_any(cur));

	trial_cpus = cpumask_weight(trial);



	raw_spin_lock_irqsave(&cur_dl_b->lock, flags);

	if (cur_dl_b->bw != -1 &&

	    cur_dl_b->bw * trial_cpus < cur_dl_b->total_bw)

		ret = 0;

	raw_spin_unlock_irqrestore(&cur_dl_b->lock, flags);

	rcu_read_unlock_sched();

	return ret;

}



bool dl_cpu_busy(unsigned int cpu)

{

	unsigned long flags;

	struct dl_bw *dl_b;

	bool overflow;

	int cpus;



	rcu_read_lock_sched();

	dl_b = dl_bw_of(cpu);

	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);

	rcu_read_unlock_sched();

	return overflow;

}

#endif



#ifdef CONFIG_SCHED_DEBUG

extern void print_dl_rq(struct seq_file *m, int cpu, struct dl_rq *dl_rq);

kernel/sched/sched.h

+14 −3
Original line number Diff line number Diff line
@@ -218,9 +218,6 @@ static inline int dl_bandwidth_enabled(void) 
	return sysctl_sched_rt_runtime >= 0;

}



extern struct dl_bw *dl_bw_of(int i);

extern int dl_bw_cpus(int i);



struct dl_bw {

	raw_spinlock_t lock;

	u64 bw, total_bw;
@@ -251,6 +248,20 @@ bool __dl_overflow(struct dl_bw *dl_b, int cpus, u64 old_bw, u64 new_bw) 


void dl_change_utilization(struct task_struct *p, u64 new_bw);

extern void init_dl_bw(struct dl_bw *dl_b);

extern int sched_dl_global_validate(void);

extern void sched_dl_do_global(void);

extern int sched_dl_overflow(struct task_struct *p, int policy,

			     const struct sched_attr *attr);

extern void __setparam_dl(struct task_struct *p, const struct sched_attr *attr);

extern void __getparam_dl(struct task_struct *p, struct sched_attr *attr);

extern bool __checkparam_dl(const struct sched_attr *attr);

extern void __dl_clear_params(struct task_struct *p);

extern bool dl_param_changed(struct task_struct *p, const struct sched_attr *attr);

extern int dl_task_can_attach(struct task_struct *p,

			      const struct cpumask *cs_cpus_allowed);

extern int dl_cpuset_cpumask_can_shrink(const struct cpumask *cur,

					const struct cpumask *trial);

extern bool dl_cpu_busy(unsigned int cpu);



#ifdef CONFIG_CGROUP_SCHED

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