summaryrefslogtreecommitdiffstats
path: root/kernel/sched.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/sched.c')
-rw-r--r--kernel/sched.c499
1 files changed, 363 insertions, 136 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index 3eedd526090..b387a8de26a 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -155,7 +155,7 @@ struct rt_prio_array {
struct list_head queue[MAX_RT_PRIO];
};
-#ifdef CONFIG_FAIR_GROUP_SCHED
+#ifdef CONFIG_GROUP_SCHED
#include <linux/cgroup.h>
@@ -165,19 +165,16 @@ static LIST_HEAD(task_groups);
/* task group related information */
struct task_group {
-#ifdef CONFIG_FAIR_CGROUP_SCHED
+#ifdef CONFIG_CGROUP_SCHED
struct cgroup_subsys_state css;
#endif
+
+#ifdef CONFIG_FAIR_GROUP_SCHED
/* schedulable entities of this group on each cpu */
struct sched_entity **se;
/* runqueue "owned" by this group on each cpu */
struct cfs_rq **cfs_rq;
- struct sched_rt_entity **rt_se;
- struct rt_rq **rt_rq;
-
- unsigned int rt_ratio;
-
/*
* shares assigned to a task group governs how much of cpu bandwidth
* is allocated to the group. The more shares a group has, the more is
@@ -213,33 +210,46 @@ struct task_group {
*
*/
unsigned long shares;
+#endif
+
+#ifdef CONFIG_RT_GROUP_SCHED
+ struct sched_rt_entity **rt_se;
+ struct rt_rq **rt_rq;
+
+ u64 rt_runtime;
+#endif
struct rcu_head rcu;
struct list_head list;
};
+#ifdef CONFIG_FAIR_GROUP_SCHED
/* Default task group's sched entity on each cpu */
static DEFINE_PER_CPU(struct sched_entity, init_sched_entity);
/* Default task group's cfs_rq on each cpu */
static DEFINE_PER_CPU(struct cfs_rq, init_cfs_rq) ____cacheline_aligned_in_smp;
-static DEFINE_PER_CPU(struct sched_rt_entity, init_sched_rt_entity);
-static DEFINE_PER_CPU(struct rt_rq, init_rt_rq) ____cacheline_aligned_in_smp;
-
static struct sched_entity *init_sched_entity_p[NR_CPUS];
static struct cfs_rq *init_cfs_rq_p[NR_CPUS];
+#endif
+
+#ifdef CONFIG_RT_GROUP_SCHED
+static DEFINE_PER_CPU(struct sched_rt_entity, init_sched_rt_entity);
+static DEFINE_PER_CPU(struct rt_rq, init_rt_rq) ____cacheline_aligned_in_smp;
static struct sched_rt_entity *init_sched_rt_entity_p[NR_CPUS];
static struct rt_rq *init_rt_rq_p[NR_CPUS];
+#endif
-/* task_group_mutex serializes add/remove of task groups and also changes to
+/* task_group_lock serializes add/remove of task groups and also changes to
* a task group's cpu shares.
*/
-static DEFINE_MUTEX(task_group_mutex);
+static DEFINE_SPINLOCK(task_group_lock);
/* doms_cur_mutex serializes access to doms_cur[] array */
static DEFINE_MUTEX(doms_cur_mutex);
+#ifdef CONFIG_FAIR_GROUP_SCHED
#ifdef CONFIG_SMP
/* kernel thread that runs rebalance_shares() periodically */
static struct task_struct *lb_monitor_task;
@@ -248,35 +258,40 @@ static int load_balance_monitor(void *unused);
static void set_se_shares(struct sched_entity *se, unsigned long shares);
+#ifdef CONFIG_USER_SCHED
+# define INIT_TASK_GROUP_LOAD (2*NICE_0_LOAD)
+#else
+# define INIT_TASK_GROUP_LOAD NICE_0_LOAD
+#endif
+
+#define MIN_GROUP_SHARES 2
+
+static int init_task_group_load = INIT_TASK_GROUP_LOAD;
+#endif
+
/* Default task group.
* Every task in system belong to this group at bootup.
*/
struct task_group init_task_group = {
+#ifdef CONFIG_FAIR_GROUP_SCHED
.se = init_sched_entity_p,
.cfs_rq = init_cfs_rq_p,
+#endif
+#ifdef CONFIG_RT_GROUP_SCHED
.rt_se = init_sched_rt_entity_p,
.rt_rq = init_rt_rq_p,
-};
-
-#ifdef CONFIG_FAIR_USER_SCHED
-# define INIT_TASK_GROUP_LOAD (2*NICE_0_LOAD)
-#else
-# define INIT_TASK_GROUP_LOAD NICE_0_LOAD
#endif
-
-#define MIN_GROUP_SHARES 2
-
-static int init_task_group_load = INIT_TASK_GROUP_LOAD;
+};
/* return group to which a task belongs */
static inline struct task_group *task_group(struct task_struct *p)
{
struct task_group *tg;
-#ifdef CONFIG_FAIR_USER_SCHED
+#ifdef CONFIG_USER_SCHED
tg = p->user->tg;
-#elif defined(CONFIG_FAIR_CGROUP_SCHED)
+#elif defined(CONFIG_CGROUP_SCHED)
tg = container_of(task_subsys_state(p, cpu_cgroup_subsys_id),
struct task_group, css);
#else
@@ -288,21 +303,15 @@ static inline struct task_group *task_group(struct task_struct *p)
/* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */
static inline void set_task_rq(struct task_struct *p, unsigned int cpu)
{
+#ifdef CONFIG_FAIR_GROUP_SCHED
p->se.cfs_rq = task_group(p)->cfs_rq[cpu];
p->se.parent = task_group(p)->se[cpu];
+#endif
+#ifdef CONFIG_RT_GROUP_SCHED
p->rt.rt_rq = task_group(p)->rt_rq[cpu];
p->rt.parent = task_group(p)->rt_se[cpu];
-}
-
-static inline void lock_task_group_list(void)
-{
- mutex_lock(&task_group_mutex);
-}
-
-static inline void unlock_task_group_list(void)
-{
- mutex_unlock(&task_group_mutex);
+#endif
}
static inline void lock_doms_cur(void)
@@ -318,12 +327,10 @@ static inline void unlock_doms_cur(void)
#else
static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { }
-static inline void lock_task_group_list(void) { }
-static inline void unlock_task_group_list(void) { }
static inline void lock_doms_cur(void) { }
static inline void unlock_doms_cur(void) { }
-#endif /* CONFIG_FAIR_GROUP_SCHED */
+#endif /* CONFIG_GROUP_SCHED */
/* CFS-related fields in a runqueue */
struct cfs_rq {
@@ -363,7 +370,7 @@ struct cfs_rq {
struct rt_rq {
struct rt_prio_array active;
unsigned long rt_nr_running;
-#if defined CONFIG_SMP || defined CONFIG_FAIR_GROUP_SCHED
+#if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
int highest_prio; /* highest queued rt task prio */
#endif
#ifdef CONFIG_SMP
@@ -373,7 +380,9 @@ struct rt_rq {
int rt_throttled;
u64 rt_time;
-#ifdef CONFIG_FAIR_GROUP_SCHED
+#ifdef CONFIG_RT_GROUP_SCHED
+ unsigned long rt_nr_boosted;
+
struct rq *rq;
struct list_head leaf_rt_rq_list;
struct task_group *tg;
@@ -447,6 +456,8 @@ struct rq {
#ifdef CONFIG_FAIR_GROUP_SCHED
/* list of leaf cfs_rq on this cpu: */
struct list_head leaf_cfs_rq_list;
+#endif
+#ifdef CONFIG_RT_GROUP_SCHED
struct list_head leaf_rt_rq_list;
#endif
@@ -652,19 +663,21 @@ const_debug unsigned int sysctl_sched_features =
const_debug unsigned int sysctl_sched_nr_migrate = 32;
/*
- * period over which we measure -rt task cpu usage in ms.
+ * period over which we measure -rt task cpu usage in us.
* default: 1s
*/
-const_debug unsigned int sysctl_sched_rt_period = 1000;
+unsigned int sysctl_sched_rt_period = 1000000;
-#define SCHED_RT_FRAC_SHIFT 16
-#define SCHED_RT_FRAC (1UL << SCHED_RT_FRAC_SHIFT)
+/*
+ * part of the period that we allow rt tasks to run in us.
+ * default: 0.95s
+ */
+int sysctl_sched_rt_runtime = 950000;
/*
- * ratio of time -rt tasks may consume.
- * default: 95%
+ * single value that denotes runtime == period, ie unlimited time.
*/
-const_debug unsigned int sysctl_sched_rt_ratio = 62259;
+#define RUNTIME_INF ((u64)~0ULL)
/*
* For kernel-internal use: high-speed (but slightly incorrect) per-cpu
@@ -1818,6 +1831,7 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync)
long old_state;
struct rq *rq;
+ smp_wmb();
rq = task_rq_lock(p, &flags);
old_state = p->state;
if (!(old_state & state))
@@ -3753,7 +3767,7 @@ void scheduler_tick(void)
#if defined(CONFIG_PREEMPT) && defined(CONFIG_DEBUG_PREEMPT)
-void add_preempt_count(int val)
+void __kprobes add_preempt_count(int val)
{
/*
* Underflow?
@@ -3769,7 +3783,7 @@ void add_preempt_count(int val)
}
EXPORT_SYMBOL(add_preempt_count);
-void sub_preempt_count(int val)
+void __kprobes sub_preempt_count(int val)
{
/*
* Underflow?
@@ -4571,6 +4585,15 @@ recheck:
return -EPERM;
}
+#ifdef CONFIG_RT_GROUP_SCHED
+ /*
+ * Do not allow realtime tasks into groups that have no runtime
+ * assigned.
+ */
+ if (rt_policy(policy) && task_group(p)->rt_runtime == 0)
+ return -EPERM;
+#endif
+
retval = security_task_setscheduler(p, policy, param);
if (retval)
return retval;
@@ -7112,7 +7135,7 @@ static void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq)
/* delimiter for bitsearch: */
__set_bit(MAX_RT_PRIO, array->bitmap);
-#if defined CONFIG_SMP || defined CONFIG_FAIR_GROUP_SCHED
+#if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
rt_rq->highest_prio = MAX_RT_PRIO;
#endif
#ifdef CONFIG_SMP
@@ -7123,7 +7146,8 @@ static void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq)
rt_rq->rt_time = 0;
rt_rq->rt_throttled = 0;
-#ifdef CONFIG_FAIR_GROUP_SCHED
+#ifdef CONFIG_RT_GROUP_SCHED
+ rt_rq->rt_nr_boosted = 0;
rt_rq->rq = rq;
#endif
}
@@ -7146,7 +7170,9 @@ static void init_tg_cfs_entry(struct rq *rq, struct task_group *tg,
se->load.inv_weight = div64_64(1ULL<<32, se->load.weight);
se->parent = NULL;
}
+#endif
+#ifdef CONFIG_RT_GROUP_SCHED
static void init_tg_rt_entry(struct rq *rq, struct task_group *tg,
struct rt_rq *rt_rq, struct sched_rt_entity *rt_se,
int cpu, int add)
@@ -7175,7 +7201,7 @@ void __init sched_init(void)
init_defrootdomain();
#endif
-#ifdef CONFIG_FAIR_GROUP_SCHED
+#ifdef CONFIG_GROUP_SCHED
list_add(&init_task_group.list, &task_groups);
#endif
@@ -7196,7 +7222,10 @@ void __init sched_init(void)
&per_cpu(init_cfs_rq, i),
&per_cpu(init_sched_entity, i), i, 1);
- init_task_group.rt_ratio = sysctl_sched_rt_ratio; /* XXX */
+#endif
+#ifdef CONFIG_RT_GROUP_SCHED
+ init_task_group.rt_runtime =
+ sysctl_sched_rt_runtime * NSEC_PER_USEC;
INIT_LIST_HEAD(&rq->leaf_rt_rq_list);
init_tg_rt_entry(rq, &init_task_group,
&per_cpu(init_rt_rq, i),
@@ -7303,7 +7332,7 @@ void normalize_rt_tasks(void)
unsigned long flags;
struct rq *rq;
- read_lock_irq(&tasklist_lock);
+ read_lock_irqsave(&tasklist_lock, flags);
do_each_thread(g, p) {
/*
* Only normalize user tasks:
@@ -7329,16 +7358,16 @@ void normalize_rt_tasks(void)
continue;
}
- spin_lock_irqsave(&p->pi_lock, flags);
+ spin_lock(&p->pi_lock);
rq = __task_rq_lock(p);
normalize_task(rq, p);
__task_rq_unlock(rq);
- spin_unlock_irqrestore(&p->pi_lock, flags);
+ spin_unlock(&p->pi_lock);
} while_each_thread(g, p);
- read_unlock_irq(&tasklist_lock);
+ read_unlock_irqrestore(&tasklist_lock, flags);
}
#endif /* CONFIG_MAGIC_SYSRQ */
@@ -7387,9 +7416,9 @@ void set_curr_task(int cpu, struct task_struct *p)
#endif
-#ifdef CONFIG_FAIR_GROUP_SCHED
+#ifdef CONFIG_GROUP_SCHED
-#ifdef CONFIG_SMP
+#if defined CONFIG_FAIR_GROUP_SCHED && defined CONFIG_SMP
/*
* distribute shares of all task groups among their schedulable entities,
* to reflect load distribution across cpus.
@@ -7540,7 +7569,8 @@ static int load_balance_monitor(void *unused)
}
#endif /* CONFIG_SMP */
-static void free_sched_group(struct task_group *tg)
+#ifdef CONFIG_FAIR_GROUP_SCHED
+static void free_fair_sched_group(struct task_group *tg)
{
int i;
@@ -7549,49 +7579,27 @@ static void free_sched_group(struct task_group *tg)
kfree(tg->cfs_rq[i]);
if (tg->se)
kfree(tg->se[i]);
- if (tg->rt_rq)
- kfree(tg->rt_rq[i]);
- if (tg->rt_se)
- kfree(tg->rt_se[i]);
}
kfree(tg->cfs_rq);
kfree(tg->se);
- kfree(tg->rt_rq);
- kfree(tg->rt_se);
- kfree(tg);
}
-/* allocate runqueue etc for a new task group */
-struct task_group *sched_create_group(void)
+static int alloc_fair_sched_group(struct task_group *tg)
{
- struct task_group *tg;
struct cfs_rq *cfs_rq;
struct sched_entity *se;
- struct rt_rq *rt_rq;
- struct sched_rt_entity *rt_se;
struct rq *rq;
int i;
- tg = kzalloc(sizeof(*tg), GFP_KERNEL);
- if (!tg)
- return ERR_PTR(-ENOMEM);
-
tg->cfs_rq = kzalloc(sizeof(cfs_rq) * NR_CPUS, GFP_KERNEL);
if (!tg->cfs_rq)
goto err;
tg->se = kzalloc(sizeof(se) * NR_CPUS, GFP_KERNEL);
if (!tg->se)
goto err;
- tg->rt_rq = kzalloc(sizeof(rt_rq) * NR_CPUS, GFP_KERNEL);
- if (!tg->rt_rq)
- goto err;
- tg->rt_se = kzalloc(sizeof(rt_se) * NR_CPUS, GFP_KERNEL);
- if (!tg->rt_se)
- goto err;
tg->shares = NICE_0_LOAD;
- tg->rt_ratio = 0; /* XXX */
for_each_possible_cpu(i) {
rq = cpu_rq(i);
@@ -7606,6 +7614,79 @@ struct task_group *sched_create_group(void)
if (!se)
goto err;
+ init_tg_cfs_entry(rq, tg, cfs_rq, se, i, 0);
+ }
+
+ return 1;
+
+ err:
+ return 0;
+}
+
+static inline void register_fair_sched_group(struct task_group *tg, int cpu)
+{
+ list_add_rcu(&tg->cfs_rq[cpu]->leaf_cfs_rq_list,
+ &cpu_rq(cpu)->leaf_cfs_rq_list);
+}
+
+static inline void unregister_fair_sched_group(struct task_group *tg, int cpu)
+{
+ list_del_rcu(&tg->cfs_rq[cpu]->leaf_cfs_rq_list);
+}
+#else
+static inline void free_fair_sched_group(struct task_group *tg)
+{
+}
+
+static inline int alloc_fair_sched_group(struct task_group *tg)
+{
+ return 1;
+}
+
+static inline void register_fair_sched_group(struct task_group *tg, int cpu)
+{
+}
+
+static inline void unregister_fair_sched_group(struct task_group *tg, int cpu)
+{
+}
+#endif
+
+#ifdef CONFIG_RT_GROUP_SCHED
+static void free_rt_sched_group(struct task_group *tg)
+{
+ int i;
+
+ for_each_possible_cpu(i) {
+ if (tg->rt_rq)
+ kfree(tg->rt_rq[i]);
+ if (tg->rt_se)
+ kfree(tg->rt_se[i]);
+ }
+
+ kfree(tg->rt_rq);
+ kfree(tg->rt_se);
+}
+
+static int alloc_rt_sched_group(struct task_group *tg)
+{
+ struct rt_rq *rt_rq;
+ struct sched_rt_entity *rt_se;
+ struct rq *rq;
+ int i;
+
+ tg->rt_rq = kzalloc(sizeof(rt_rq) * NR_CPUS, GFP_KERNEL);
+ if (!tg->rt_rq)
+ goto err;
+ tg->rt_se = kzalloc(sizeof(rt_se) * NR_CPUS, GFP_KERNEL);
+ if (!tg->rt_se)
+ goto err;
+
+ tg->rt_runtime = 0;
+
+ for_each_possible_cpu(i) {
+ rq = cpu_rq(i);
+
rt_rq = kmalloc_node(sizeof(struct rt_rq),
GFP_KERNEL|__GFP_ZERO, cpu_to_node(i));
if (!rt_rq)
@@ -7616,20 +7697,75 @@ struct task_group *sched_create_group(void)
if (!rt_se)
goto err;
- init_tg_cfs_entry(rq, tg, cfs_rq, se, i, 0);
init_tg_rt_entry(rq, tg, rt_rq, rt_se, i, 0);
}
- lock_task_group_list();
+ return 1;
+
+ err:
+ return 0;
+}
+
+static inline void register_rt_sched_group(struct task_group *tg, int cpu)
+{
+ list_add_rcu(&tg->rt_rq[cpu]->leaf_rt_rq_list,
+ &cpu_rq(cpu)->leaf_rt_rq_list);
+}
+
+static inline void unregister_rt_sched_group(struct task_group *tg, int cpu)
+{
+ list_del_rcu(&tg->rt_rq[cpu]->leaf_rt_rq_list);
+}
+#else
+static inline void free_rt_sched_group(struct task_group *tg)
+{
+}
+
+static inline int alloc_rt_sched_group(struct task_group *tg)
+{
+ return 1;
+}
+
+static inline void register_rt_sched_group(struct task_group *tg, int cpu)
+{
+}
+
+static inline void unregister_rt_sched_group(struct task_group *tg, int cpu)
+{
+}
+#endif
+
+static void free_sched_group(struct task_group *tg)
+{
+ free_fair_sched_group(tg);
+ free_rt_sched_group(tg);
+ kfree(tg);
+}
+
+/* allocate runqueue etc for a new task group */
+struct task_group *sched_create_group(void)
+{
+ struct task_group *tg;
+ unsigned long flags;
+ int i;
+
+ tg = kzalloc(sizeof(*tg), GFP_KERNEL);
+ if (!tg)
+ return ERR_PTR(-ENOMEM);
+
+ if (!alloc_fair_sched_group(tg))
+ goto err;
+
+ if (!alloc_rt_sched_group(tg))
+ goto err;
+
+ spin_lock_irqsave(&task_group_lock, flags);
for_each_possible_cpu(i) {
- rq = cpu_rq(i);
- cfs_rq = tg->cfs_rq[i];
- list_add_rcu(&cfs_rq->leaf_cfs_rq_list, &rq->leaf_cfs_rq_list);
- rt_rq = tg->rt_rq[i];
- list_add_rcu(&rt_rq->leaf_rt_rq_list, &rq->leaf_rt_rq_list);
+ register_fair_sched_group(tg, i);
+ register_rt_sched_group(tg, i);
}
list_add_rcu(&tg->list, &task_groups);
- unlock_task_group_list();
+ spin_unlock_irqrestore(&task_group_lock, flags);
return tg;
@@ -7648,21 +7784,16 @@ static void free_sched_group_rcu(struct rcu_head *rhp)
/* Destroy runqueue etc associated with a task group */
void sched_destroy_group(struct task_group *tg)
{
- struct cfs_rq *cfs_rq = NULL;
- struct rt_rq *rt_rq = NULL;
+ unsigned long flags;
int i;
- lock_task_group_list();
+ spin_lock_irqsave(&task_group_lock, flags);
for_each_possible_cpu(i) {
- cfs_rq = tg->cfs_rq[i];
- list_del_rcu(&cfs_rq->leaf_cfs_rq_list);
- rt_rq = tg->rt_rq[i];
- list_del_rcu(&rt_rq->leaf_rt_rq_list);
+ unregister_fair_sched_group(tg, i);
+ unregister_rt_sched_group(tg, i);
}
list_del_rcu(&tg->list);
- unlock_task_group_list();
-
- BUG_ON(!cfs_rq);
+ spin_unlock_irqrestore(&task_group_lock, flags);
/* wait for possible concurrent references to cfs_rqs complete */
call_rcu(&tg->rcu, free_sched_group_rcu);
@@ -7703,6 +7834,7 @@ void sched_move_task(struct task_struct *tsk)
task_rq_unlock(rq, &flags);
}
+#ifdef CONFIG_FAIR_GROUP_SCHED
/* rq->lock to be locked by caller */
static void set_se_shares(struct sched_entity *se, unsigned long shares)
{
@@ -7728,13 +7860,14 @@ static void set_se_shares(struct sched_entity *se, unsigned long shares)
}
}
+static DEFINE_MUTEX(shares_mutex);
+
int sched_group_set_shares(struct task_group *tg, unsigned long shares)
{
int i;
- struct cfs_rq *cfs_rq;
- struct rq *rq;
+ unsigned long flags;
- lock_task_group_list();
+ mutex_lock(&shares_mutex);
if (tg->shares == shares)
goto done;
@@ -7746,10 +7879,10 @@ int sched_group_set_shares(struct task_group *tg, unsigned long shares)
* load_balance_fair) from referring to this group first,
* by taking it off the rq->leaf_cfs_rq_list on each cpu.
*/
- for_each_possible_cpu(i) {
- cfs_rq = tg->cfs_rq[i];
- list_del_rcu(&cfs_rq->leaf_cfs_rq_list);
- }
+ spin_lock_irqsave(&task_group_lock, flags);
+ for_each_possible_cpu(i)
+ unregister_fair_sched_group(tg, i);
+ spin_unlock_irqrestore(&task_group_lock, flags);
/* wait for any ongoing reference to this group to finish */
synchronize_sched();
@@ -7769,13 +7902,12 @@ int sched_group_set_shares(struct task_group *tg, unsigned long shares)
* Enable load balance activity on this group, by inserting it back on
* each cpu's rq->leaf_cfs_rq_list.
*/
- for_each_possible_cpu(i) {
- rq = cpu_rq(i);
- cfs_rq = tg->cfs_rq[i];
- list_add_rcu(&cfs_rq->leaf_cfs_rq_list, &rq->leaf_cfs_rq_list);
- }
+ spin_lock_irqsave(&task_group_lock, flags);
+ for_each_possible_cpu(i)
+ register_fair_sched_group(tg, i);
+ spin_unlock_irqrestore(&task_group_lock, flags);
done:
- unlock_task_group_list();
+ mutex_unlock(&shares_mutex);
return 0;
}
@@ -7783,35 +7915,84 @@ unsigned long sched_group_shares(struct task_group *tg)
{
return tg->shares;
}
+#endif
+#ifdef CONFIG_RT_GROUP_SCHED
/*
- * Ensure the total rt_ratio <= sysctl_sched_rt_ratio
+ * Ensure that the real time constraints are schedulable.
*/
-int sched_group_set_rt_ratio(struct task_group *tg, unsigned long rt_ratio)
+static DEFINE_MUTEX(rt_constraints_mutex);
+
+static unsigned long to_ratio(u64 period, u64 runtime)
+{
+ if (runtime == RUNTIME_INF)
+ return 1ULL << 16;
+
+ runtime *= (1ULL << 16);
+ div64_64(runtime, period);
+ return runtime;
+}
+
+static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime)
{
struct task_group *tgi;
unsigned long total = 0;
+ unsigned long global_ratio =
+ to_ratio(sysctl_sched_rt_period,
+ sysctl_sched_rt_runtime < 0 ?
+ RUNTIME_INF : sysctl_sched_rt_runtime);
rcu_read_lock();
- list_for_each_entry_rcu(tgi, &task_groups, list)
- total += tgi->rt_ratio;
- rcu_read_unlock();
+ list_for_each_entry_rcu(tgi, &task_groups, list) {
+ if (tgi == tg)
+ continue;
- if (total + rt_ratio - tg->rt_ratio > sysctl_sched_rt_ratio)
- return -EINVAL;
+ total += to_ratio(period, tgi->rt_runtime);
+ }
+ rcu_read_unlock();
- tg->rt_ratio = rt_ratio;
- return 0;
+ return total + to_ratio(period, runtime) < global_ratio;
}
-unsigned long sched_group_rt_ratio(struct task_group *tg)
+int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us)
{
- return tg->rt_ratio;
+ u64 rt_runtime, rt_period;
+ int err = 0;
+
+ rt_period = sysctl_sched_rt_period * NSEC_PER_USEC;
+ rt_runtime = (u64)rt_runtime_us * NSEC_PER_USEC;
+ if (rt_runtime_us == -1)
+ rt_runtime = rt_period;
+
+ mutex_lock(&rt_constraints_mutex);
+ if (!__rt_schedulable(tg, rt_period, rt_runtime)) {
+ err = -EINVAL;
+ goto unlock;
+ }
+ if (rt_runtime_us == -1)
+ rt_runtime = RUNTIME_INF;
+ tg->rt_runtime = rt_runtime;
+ unlock:
+ mutex_unlock(&rt_constraints_mutex);
+
+ return err;
}
-#endif /* CONFIG_FAIR_GROUP_SCHED */
+long sched_group_rt_runtime(struct task_group *tg)
+{
+ u64 rt_runtime_us;
+
+ if (tg->rt_runtime == RUNTIME_INF)
+ return -1;
+
+ rt_runtime_us = tg->rt_runtime;
+ do_div(rt_runtime_us, NSEC_PER_USEC);
+ return rt_runtime_us;
+}
+#endif
+#endif /* CONFIG_GROUP_SCHED */
-#ifdef CONFIG_FAIR_CGROUP_SCHED
+#ifdef CONFIG_CGROUP_SCHED
/* return corresponding task_group object of a cgroup */
static inline struct task_group *cgroup_tg(struct cgroup *cgrp)
@@ -7857,9 +8038,15 @@ static int
cpu_cgroup_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
struct task_struct *tsk)
{
+#ifdef CONFIG_RT_GROUP_SCHED
+ /* Don't accept realtime tasks when there is no way for them to run */
+ if (rt_task(tsk) && cgroup_tg(cgrp)->rt_runtime == 0)
+ return -EINVAL;
+#else
/* We don't support RT-tasks being in separate groups */
if (tsk->sched_class != &fair_sched_class)
return -EINVAL;
+#endif
return 0;
}
@@ -7871,6 +8058,7 @@ cpu_cgroup_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
sched_move_task(tsk);
}
+#ifdef CONFIG_FAIR_GROUP_SCHED
static int cpu_shares_write_uint(struct cgroup *cgrp, struct cftype *cftype,
u64 shareval)
{
@@ -7883,31 +8071,70 @@ static u64 cpu_shares_read_uint(struct cgroup *cgrp, struct cftype *cft)
return (u64) tg->shares;
}
+#endif
-static int cpu_rt_ratio_write_uint(struct cgroup *cgrp, struct cftype *cftype,
- u64 rt_ratio_val)
+#ifdef CONFIG_RT_GROUP_SCHED
+static int cpu_rt_runtime_write(struct cgroup *cgrp, struct cftype *cft,
+ struct file *file,
+ const char __user *userbuf,
+ size_t nbytes, loff_t *unused_ppos)
{
- return sched_group_set_rt_ratio(cgroup_tg(cgrp), rt_ratio_val);
+ char buffer[64];
+ int retval = 0;
+ s64 val;
+ char *end;
+
+ if (!nbytes)
+ return -EINVAL;
+ if (nbytes >= sizeof(buffer))
+ return -E2BIG;
+ if (copy_from_user(buffer, userbuf, nbytes))
+ return -EFAULT;
+
+ buffer[nbytes] = 0; /* nul-terminate */
+
+ /* strip newline if necessary */
+ if (nbytes && (buffer[nbytes-1] == '\n'))
+ buffer[nbytes-1] = 0;
+ val = simple_strtoll(buffer, &end, 0);
+ if (*end)
+ return -EINVAL;
+
+ /* Pass to subsystem */
+ retval = sched_group_set_rt_runtime(cgroup_tg(cgrp), val);
+ if (!retval)
+ retval = nbytes;
+ return retval;
}
-static u64 cpu_rt_ratio_read_uint(struct cgroup *cgrp, struct cftype *cft)
+static ssize_t cpu_rt_runtime_read(struct cgroup *cgrp, struct cftype *cft,
+ struct file *file,
+ char __user *buf, size_t nbytes,
+ loff_t *ppos)
{
- struct task_group *tg = cgroup_tg(cgrp);
+ char tmp[64];
+ long val = sched_group_rt_runtime(cgroup_tg(cgrp));
+ int len = sprintf(tmp, "%ld\n", val);
- return (u64) tg->rt_ratio;
+ return simple_read_from_buffer(buf, nbytes, ppos, tmp, len);
}
+#endif
static struct cftype cpu_files[] = {
+#ifdef CONFIG_FAIR_GROUP_SCHED
{
.name = "shares",
.read_uint = cpu_shares_read_uint,
.write_uint = cpu_shares_write_uint,
},
+#endif
+#ifdef CONFIG_RT_GROUP_SCHED
{
- .name = "rt_ratio",
- .read_uint = cpu_rt_ratio_read_uint,
- .write_uint = cpu_rt_ratio_write_uint,
+ .name = "rt_runtime_us",
+ .read = cpu_rt_runtime_read,
+ .write = cpu_rt_runtime_write,
},
+#endif
};
static int cpu_cgroup_populate(struct cgroup_subsys *ss, struct cgroup *cont)
@@ -7926,7 +8153,7 @@ struct cgroup_subsys cpu_cgroup_subsys = {
.early_init = 1,
};
-#endif /* CONFIG_FAIR_CGROUP_SCHED */
+#endif /* CONFIG_CGROUP_SCHED */
#ifdef CONFIG_CGROUP_CPUACCT