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authorArjan van de Ven <arjan@linux.intel.com>2008-10-17 09:20:26 -0700
committerArjan van de Ven <arjan@linux.intel.com>2008-10-17 09:20:26 -0700
commit651dab4264e4ba0e563f5ff56f748127246e9065 (patch)
tree016630974bdcb00fe529b673f96d389e0fd6dc94 /kernel/sched.c
parent40b8606253552109815786e5d4b0de98782d31f5 (diff)
parent2e532d68a2b3e2aa6b19731501222069735c741c (diff)
downloadop-kernel-dev-651dab4264e4ba0e563f5ff56f748127246e9065.zip
op-kernel-dev-651dab4264e4ba0e563f5ff56f748127246e9065.tar.gz
Merge commit 'linus/master' into merge-linus
Conflicts: arch/x86/kvm/i8254.c
Diffstat (limited to 'kernel/sched.c')
-rw-r--r--kernel/sched.c408
1 files changed, 262 insertions, 146 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index e46b5af..eb3c729 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -201,14 +201,19 @@ void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime)
hrtimer_init(&rt_b->rt_period_timer,
CLOCK_MONOTONIC, HRTIMER_MODE_REL);
rt_b->rt_period_timer.function = sched_rt_period_timer;
- rt_b->rt_period_timer.cb_mode = HRTIMER_CB_IRQSAFE_NO_SOFTIRQ;
+ rt_b->rt_period_timer.cb_mode = HRTIMER_CB_IRQSAFE_UNLOCKED;
+}
+
+static inline int rt_bandwidth_enabled(void)
+{
+ return sysctl_sched_rt_runtime >= 0;
}
static void start_rt_bandwidth(struct rt_bandwidth *rt_b)
{
ktime_t now;
- if (rt_b->rt_runtime == RUNTIME_INF)
+ if (rt_bandwidth_enabled() && rt_b->rt_runtime == RUNTIME_INF)
return;
if (hrtimer_active(&rt_b->rt_period_timer))
@@ -297,9 +302,9 @@ 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;
#endif /* CONFIG_RT_GROUP_SCHED */
-#else /* !CONFIG_FAIR_GROUP_SCHED */
+#else /* !CONFIG_USER_SCHED */
#define root_task_group init_task_group
-#endif /* CONFIG_FAIR_GROUP_SCHED */
+#endif /* CONFIG_USER_SCHED */
/* task_group_lock serializes add/remove of task groups and also changes to
* a task group's cpu shares.
@@ -603,9 +608,9 @@ struct rq {
static DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
-static inline void check_preempt_curr(struct rq *rq, struct task_struct *p)
+static inline void check_preempt_curr(struct rq *rq, struct task_struct *p, int sync)
{
- rq->curr->sched_class->check_preempt_curr(rq, p);
+ rq->curr->sched_class->check_preempt_curr(rq, p, sync);
}
static inline int cpu_of(struct rq *rq)
@@ -1086,7 +1091,7 @@ hotplug_hrtick(struct notifier_block *nfb, unsigned long action, void *hcpu)
return NOTIFY_DONE;
}
-static void init_hrtick(void)
+static __init void init_hrtick(void)
{
hotcpu_notifier(hotplug_hrtick, 0);
}
@@ -1101,7 +1106,7 @@ static void hrtick_start(struct rq *rq, u64 delay)
hrtimer_start(&rq->hrtick_timer, ns_to_ktime(delay), HRTIMER_MODE_REL);
}
-static void init_hrtick(void)
+static inline void init_hrtick(void)
{
}
#endif /* CONFIG_SMP */
@@ -1118,9 +1123,9 @@ static void init_rq_hrtick(struct rq *rq)
hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
rq->hrtick_timer.function = hrtick;
- rq->hrtick_timer.cb_mode = HRTIMER_CB_IRQSAFE_NO_SOFTIRQ;
+ rq->hrtick_timer.cb_mode = HRTIMER_CB_IRQSAFE_PERCPU;
}
-#else
+#else /* CONFIG_SCHED_HRTICK */
static inline void hrtick_clear(struct rq *rq)
{
}
@@ -1132,7 +1137,7 @@ static inline void init_rq_hrtick(struct rq *rq)
static inline void init_hrtick(void)
{
}
-#endif
+#endif /* CONFIG_SCHED_HRTICK */
/*
* resched_task - mark a task 'to be rescheduled now'.
@@ -1379,38 +1384,24 @@ static inline void dec_cpu_load(struct rq *rq, unsigned long load)
update_load_sub(&rq->load, load);
}
-#ifdef CONFIG_SMP
-static unsigned long source_load(int cpu, int type);
-static unsigned long target_load(int cpu, int type);
-static int task_hot(struct task_struct *p, u64 now, struct sched_domain *sd);
-
-static unsigned long cpu_avg_load_per_task(int cpu)
-{
- struct rq *rq = cpu_rq(cpu);
-
- if (rq->nr_running)
- rq->avg_load_per_task = rq->load.weight / rq->nr_running;
-
- return rq->avg_load_per_task;
-}
-
-#ifdef CONFIG_FAIR_GROUP_SCHED
-
-typedef void (*tg_visitor)(struct task_group *, int, struct sched_domain *);
+#if (defined(CONFIG_SMP) && defined(CONFIG_FAIR_GROUP_SCHED)) || defined(CONFIG_RT_GROUP_SCHED)
+typedef int (*tg_visitor)(struct task_group *, void *);
/*
* Iterate the full tree, calling @down when first entering a node and @up when
* leaving it for the final time.
*/
-static void
-walk_tg_tree(tg_visitor down, tg_visitor up, int cpu, struct sched_domain *sd)
+static int walk_tg_tree(tg_visitor down, tg_visitor up, void *data)
{
struct task_group *parent, *child;
+ int ret;
rcu_read_lock();
parent = &root_task_group;
down:
- (*down)(parent, cpu, sd);
+ ret = (*down)(parent, data);
+ if (ret)
+ goto out_unlock;
list_for_each_entry_rcu(child, &parent->children, siblings) {
parent = child;
goto down;
@@ -1418,15 +1409,43 @@ down:
up:
continue;
}
- (*up)(parent, cpu, sd);
+ ret = (*up)(parent, data);
+ if (ret)
+ goto out_unlock;
child = parent;
parent = parent->parent;
if (parent)
goto up;
+out_unlock:
rcu_read_unlock();
+
+ return ret;
+}
+
+static int tg_nop(struct task_group *tg, void *data)
+{
+ return 0;
+}
+#endif
+
+#ifdef CONFIG_SMP
+static unsigned long source_load(int cpu, int type);
+static unsigned long target_load(int cpu, int type);
+static int task_hot(struct task_struct *p, u64 now, struct sched_domain *sd);
+
+static unsigned long cpu_avg_load_per_task(int cpu)
+{
+ struct rq *rq = cpu_rq(cpu);
+
+ if (rq->nr_running)
+ rq->avg_load_per_task = rq->load.weight / rq->nr_running;
+
+ return rq->avg_load_per_task;
}
+#ifdef CONFIG_FAIR_GROUP_SCHED
+
static void __set_se_shares(struct sched_entity *se, unsigned long shares);
/*
@@ -1485,11 +1504,11 @@ __update_group_shares_cpu(struct task_group *tg, int cpu,
* This needs to be done in a bottom-up fashion because the rq weight of a
* parent group depends on the shares of its child groups.
*/
-static void
-tg_shares_up(struct task_group *tg, int cpu, struct sched_domain *sd)
+static int tg_shares_up(struct task_group *tg, void *data)
{
unsigned long rq_weight = 0;
unsigned long shares = 0;
+ struct sched_domain *sd = data;
int i;
for_each_cpu_mask(i, sd->span) {
@@ -1514,6 +1533,8 @@ tg_shares_up(struct task_group *tg, int cpu, struct sched_domain *sd)
__update_group_shares_cpu(tg, i, shares, rq_weight);
spin_unlock_irqrestore(&rq->lock, flags);
}
+
+ return 0;
}
/*
@@ -1521,10 +1542,10 @@ tg_shares_up(struct task_group *tg, int cpu, struct sched_domain *sd)
* This needs to be done in a top-down fashion because the load of a child
* group is a fraction of its parents load.
*/
-static void
-tg_load_down(struct task_group *tg, int cpu, struct sched_domain *sd)
+static int tg_load_down(struct task_group *tg, void *data)
{
unsigned long load;
+ long cpu = (long)data;
if (!tg->parent) {
load = cpu_rq(cpu)->load.weight;
@@ -1535,11 +1556,8 @@ tg_load_down(struct task_group *tg, int cpu, struct sched_domain *sd)
}
tg->cfs_rq[cpu]->h_load = load;
-}
-static void
-tg_nop(struct task_group *tg, int cpu, struct sched_domain *sd)
-{
+ return 0;
}
static void update_shares(struct sched_domain *sd)
@@ -1549,7 +1567,7 @@ static void update_shares(struct sched_domain *sd)
if (elapsed >= (s64)(u64)sysctl_sched_shares_ratelimit) {
sd->last_update = now;
- walk_tg_tree(tg_nop, tg_shares_up, 0, sd);
+ walk_tg_tree(tg_nop, tg_shares_up, sd);
}
}
@@ -1560,9 +1578,9 @@ static void update_shares_locked(struct rq *rq, struct sched_domain *sd)
spin_lock(&rq->lock);
}
-static void update_h_load(int cpu)
+static void update_h_load(long cpu)
{
- walk_tg_tree(tg_load_down, tg_nop, cpu, NULL);
+ walk_tg_tree(tg_load_down, tg_nop, (void *)cpu);
}
#else
@@ -1920,11 +1938,8 @@ unsigned long wait_task_inactive(struct task_struct *p, long match_state)
running = task_running(rq, p);
on_rq = p->se.on_rq;
ncsw = 0;
- if (!match_state || p->state == match_state) {
- ncsw = p->nivcsw + p->nvcsw;
- if (unlikely(!ncsw))
- ncsw = 1;
- }
+ if (!match_state || p->state == match_state)
+ ncsw = p->nvcsw | LONG_MIN; /* sets MSB */
task_rq_unlock(rq, &flags);
/*
@@ -2284,7 +2299,7 @@ out_running:
trace_mark(kernel_sched_wakeup,
"pid %d state %ld ## rq %p task %p rq->curr %p",
p->pid, p->state, rq, p, rq->curr);
- check_preempt_curr(rq, p);
+ check_preempt_curr(rq, p, sync);
p->state = TASK_RUNNING;
#ifdef CONFIG_SMP
@@ -2419,7 +2434,7 @@ void wake_up_new_task(struct task_struct *p, unsigned long clone_flags)
trace_mark(kernel_sched_wakeup_new,
"pid %d state %ld ## rq %p task %p rq->curr %p",
p->pid, p->state, rq, p, rq->curr);
- check_preempt_curr(rq, p);
+ check_preempt_curr(rq, p, 0);
#ifdef CONFIG_SMP
if (p->sched_class->task_wake_up)
p->sched_class->task_wake_up(rq, p);
@@ -2879,7 +2894,7 @@ static void pull_task(struct rq *src_rq, struct task_struct *p,
* Note that idle threads have a prio of MAX_PRIO, for this test
* to be always true for them.
*/
- check_preempt_curr(this_rq, p);
+ check_preempt_curr(this_rq, p, 0);
}
/*
@@ -4626,6 +4641,15 @@ __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive)
}
EXPORT_SYMBOL_GPL(__wake_up_sync); /* For internal use only */
+/**
+ * complete: - signals a single thread waiting on this completion
+ * @x: holds the state of this particular completion
+ *
+ * This will wake up a single thread waiting on this completion. Threads will be
+ * awakened in the same order in which they were queued.
+ *
+ * See also complete_all(), wait_for_completion() and related routines.
+ */
void complete(struct completion *x)
{
unsigned long flags;
@@ -4637,6 +4661,12 @@ void complete(struct completion *x)
}
EXPORT_SYMBOL(complete);
+/**
+ * complete_all: - signals all threads waiting on this completion
+ * @x: holds the state of this particular completion
+ *
+ * This will wake up all threads waiting on this particular completion event.
+ */
void complete_all(struct completion *x)
{
unsigned long flags;
@@ -4657,10 +4687,7 @@ do_wait_for_common(struct completion *x, long timeout, int state)
wait.flags |= WQ_FLAG_EXCLUSIVE;
__add_wait_queue_tail(&x->wait, &wait);
do {
- if ((state == TASK_INTERRUPTIBLE &&
- signal_pending(current)) ||
- (state == TASK_KILLABLE &&
- fatal_signal_pending(current))) {
+ if (signal_pending_state(state, current)) {
timeout = -ERESTARTSYS;
break;
}
@@ -4688,12 +4715,31 @@ wait_for_common(struct completion *x, long timeout, int state)
return timeout;
}
+/**
+ * wait_for_completion: - waits for completion of a task
+ * @x: holds the state of this particular completion
+ *
+ * This waits to be signaled for completion of a specific task. It is NOT
+ * interruptible and there is no timeout.
+ *
+ * See also similar routines (i.e. wait_for_completion_timeout()) with timeout
+ * and interrupt capability. Also see complete().
+ */
void __sched wait_for_completion(struct completion *x)
{
wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE);
}
EXPORT_SYMBOL(wait_for_completion);
+/**
+ * wait_for_completion_timeout: - waits for completion of a task (w/timeout)
+ * @x: holds the state of this particular completion
+ * @timeout: timeout value in jiffies
+ *
+ * This waits for either a completion of a specific task to be signaled or for a
+ * specified timeout to expire. The timeout is in jiffies. It is not
+ * interruptible.
+ */
unsigned long __sched
wait_for_completion_timeout(struct completion *x, unsigned long timeout)
{
@@ -4701,6 +4747,13 @@ wait_for_completion_timeout(struct completion *x, unsigned long timeout)
}
EXPORT_SYMBOL(wait_for_completion_timeout);
+/**
+ * wait_for_completion_interruptible: - waits for completion of a task (w/intr)
+ * @x: holds the state of this particular completion
+ *
+ * This waits for completion of a specific task to be signaled. It is
+ * interruptible.
+ */
int __sched wait_for_completion_interruptible(struct completion *x)
{
long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE);
@@ -4710,6 +4763,14 @@ int __sched wait_for_completion_interruptible(struct completion *x)
}
EXPORT_SYMBOL(wait_for_completion_interruptible);
+/**
+ * wait_for_completion_interruptible_timeout: - waits for completion (w/(to,intr))
+ * @x: holds the state of this particular completion
+ * @timeout: timeout value in jiffies
+ *
+ * This waits for either a completion of a specific task to be signaled or for a
+ * specified timeout to expire. It is interruptible. The timeout is in jiffies.
+ */
unsigned long __sched
wait_for_completion_interruptible_timeout(struct completion *x,
unsigned long timeout)
@@ -4718,6 +4779,13 @@ wait_for_completion_interruptible_timeout(struct completion *x,
}
EXPORT_SYMBOL(wait_for_completion_interruptible_timeout);
+/**
+ * wait_for_completion_killable: - waits for completion of a task (killable)
+ * @x: holds the state of this particular completion
+ *
+ * This waits to be signaled for completion of a specific task. It can be
+ * interrupted by a kill signal.
+ */
int __sched wait_for_completion_killable(struct completion *x)
{
long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_KILLABLE);
@@ -5120,7 +5188,8 @@ recheck:
* Do not allow realtime tasks into groups that have no runtime
* assigned.
*/
- if (rt_policy(policy) && task_group(p)->rt_bandwidth.rt_runtime == 0)
+ if (rt_bandwidth_enabled() && rt_policy(policy) &&
+ task_group(p)->rt_bandwidth.rt_runtime == 0)
return -EPERM;
#endif
@@ -5956,7 +6025,7 @@ static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu)
set_task_cpu(p, dest_cpu);
if (on_rq) {
activate_task(rq_dest, p, 0);
- check_preempt_curr(rq_dest, p);
+ check_preempt_curr(rq_dest, p, 0);
}
done:
ret = 1;
@@ -6281,7 +6350,7 @@ set_table_entry(struct ctl_table *entry,
static struct ctl_table *
sd_alloc_ctl_domain_table(struct sched_domain *sd)
{
- struct ctl_table *table = sd_alloc_ctl_entry(12);
+ struct ctl_table *table = sd_alloc_ctl_entry(13);
if (table == NULL)
return NULL;
@@ -6309,7 +6378,9 @@ sd_alloc_ctl_domain_table(struct sched_domain *sd)
sizeof(int), 0644, proc_dointvec_minmax);
set_table_entry(&table[10], "flags", &sd->flags,
sizeof(int), 0644, proc_dointvec_minmax);
- /* &table[11] is terminator */
+ set_table_entry(&table[11], "name", sd->name,
+ CORENAME_MAX_SIZE, 0444, proc_dostring);
+ /* &table[12] is terminator */
return table;
}
@@ -7193,13 +7264,21 @@ static void init_sched_groups_power(int cpu, struct sched_domain *sd)
* Non-inlined to reduce accumulated stack pressure in build_sched_domains()
*/
+#ifdef CONFIG_SCHED_DEBUG
+# define SD_INIT_NAME(sd, type) sd->name = #type
+#else
+# define SD_INIT_NAME(sd, type) do { } while (0)
+#endif
+
#define SD_INIT(sd, type) sd_init_##type(sd)
+
#define SD_INIT_FUNC(type) \
static noinline void sd_init_##type(struct sched_domain *sd) \
{ \
memset(sd, 0, sizeof(*sd)); \
*sd = SD_##type##_INIT; \
sd->level = SD_LV_##type; \
+ SD_INIT_NAME(sd, type); \
}
SD_INIT_FUNC(CPU)
@@ -7695,24 +7774,27 @@ static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur,
* and partition_sched_domains() will fallback to the single partition
* 'fallback_doms', it also forces the domains to be rebuilt.
*
+ * If doms_new==NULL it will be replaced with cpu_online_map.
+ * ndoms_new==0 is a special case for destroying existing domains.
+ * It will not create the default domain.
+ *
* Call with hotplug lock held
*/
void partition_sched_domains(int ndoms_new, cpumask_t *doms_new,
struct sched_domain_attr *dattr_new)
{
- int i, j;
+ int i, j, n;
mutex_lock(&sched_domains_mutex);
/* always unregister in case we don't destroy any domains */
unregister_sched_domain_sysctl();
- if (doms_new == NULL)
- ndoms_new = 0;
+ n = doms_new ? ndoms_new : 0;
/* Destroy deleted domains */
for (i = 0; i < ndoms_cur; i++) {
- for (j = 0; j < ndoms_new; j++) {
+ for (j = 0; j < n; j++) {
if (cpus_equal(doms_cur[i], doms_new[j])
&& dattrs_equal(dattr_cur, i, dattr_new, j))
goto match1;
@@ -7725,7 +7807,6 @@ match1:
if (doms_new == NULL) {
ndoms_cur = 0;
- ndoms_new = 1;
doms_new = &fallback_doms;
cpus_andnot(doms_new[0], cpu_online_map, cpu_isolated_map);
dattr_new = NULL;
@@ -7762,8 +7843,13 @@ match2:
int arch_reinit_sched_domains(void)
{
get_online_cpus();
+
+ /* Destroy domains first to force the rebuild */
+ partition_sched_domains(0, NULL, NULL);
+
rebuild_sched_domains();
put_online_cpus();
+
return 0;
}
@@ -7847,7 +7933,7 @@ static int update_sched_domains(struct notifier_block *nfb,
case CPU_ONLINE_FROZEN:
case CPU_DEAD:
case CPU_DEAD_FROZEN:
- partition_sched_domains(0, NULL, NULL);
+ partition_sched_domains(1, NULL, NULL);
return NOTIFY_OK;
default:
@@ -8234,20 +8320,25 @@ void __might_sleep(char *file, int line)
#ifdef in_atomic
static unsigned long prev_jiffy; /* ratelimiting */
- if ((in_atomic() || irqs_disabled()) &&
- system_state == SYSTEM_RUNNING && !oops_in_progress) {
- if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy)
- return;
- prev_jiffy = jiffies;
- printk(KERN_ERR "BUG: sleeping function called from invalid"
- " context at %s:%d\n", file, line);
- printk("in_atomic():%d, irqs_disabled():%d\n",
- in_atomic(), irqs_disabled());
- debug_show_held_locks(current);
- if (irqs_disabled())
- print_irqtrace_events(current);
- dump_stack();
- }
+ if ((!in_atomic() && !irqs_disabled()) ||
+ system_state != SYSTEM_RUNNING || oops_in_progress)
+ return;
+ if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy)
+ return;
+ prev_jiffy = jiffies;
+
+ printk(KERN_ERR
+ "BUG: sleeping function called from invalid context at %s:%d\n",
+ file, line);
+ printk(KERN_ERR
+ "in_atomic(): %d, irqs_disabled(): %d, pid: %d, name: %s\n",
+ in_atomic(), irqs_disabled(),
+ current->pid, current->comm);
+
+ debug_show_held_locks(current);
+ if (irqs_disabled())
+ print_irqtrace_events(current);
+ dump_stack();
#endif
}
EXPORT_SYMBOL(__might_sleep);
@@ -8745,73 +8836,95 @@ static DEFINE_MUTEX(rt_constraints_mutex);
static unsigned long to_ratio(u64 period, u64 runtime)
{
if (runtime == RUNTIME_INF)
- return 1ULL << 16;
+ return 1ULL << 20;
- return div64_u64(runtime << 16, period);
+ return div64_u64(runtime << 20, period);
}
-#ifdef CONFIG_CGROUP_SCHED
-static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime)
+/* Must be called with tasklist_lock held */
+static inline int tg_has_rt_tasks(struct task_group *tg)
{
- struct task_group *tgi, *parent = tg->parent;
- unsigned long total = 0;
+ struct task_struct *g, *p;
- if (!parent) {
- if (global_rt_period() < period)
- return 0;
+ do_each_thread(g, p) {
+ if (rt_task(p) && rt_rq_of_se(&p->rt)->tg == tg)
+ return 1;
+ } while_each_thread(g, p);
- return to_ratio(period, runtime) <
- to_ratio(global_rt_period(), global_rt_runtime());
- }
+ return 0;
+}
- if (ktime_to_ns(parent->rt_bandwidth.rt_period) < period)
- return 0;
+struct rt_schedulable_data {
+ struct task_group *tg;
+ u64 rt_period;
+ u64 rt_runtime;
+};
- rcu_read_lock();
- list_for_each_entry_rcu(tgi, &parent->children, siblings) {
- if (tgi == tg)
- continue;
+static int tg_schedulable(struct task_group *tg, void *data)
+{
+ struct rt_schedulable_data *d = data;
+ struct task_group *child;
+ unsigned long total, sum = 0;
+ u64 period, runtime;
+
+ period = ktime_to_ns(tg->rt_bandwidth.rt_period);
+ runtime = tg->rt_bandwidth.rt_runtime;
- total += to_ratio(ktime_to_ns(tgi->rt_bandwidth.rt_period),
- tgi->rt_bandwidth.rt_runtime);
+ if (tg == d->tg) {
+ period = d->rt_period;
+ runtime = d->rt_runtime;
}
- rcu_read_unlock();
- return total + to_ratio(period, runtime) <=
- to_ratio(ktime_to_ns(parent->rt_bandwidth.rt_period),
- parent->rt_bandwidth.rt_runtime);
-}
-#elif defined CONFIG_USER_SCHED
-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(global_rt_period(), global_rt_runtime());
+ /*
+ * Cannot have more runtime than the period.
+ */
+ if (runtime > period && runtime != RUNTIME_INF)
+ return -EINVAL;
- rcu_read_lock();
- list_for_each_entry_rcu(tgi, &task_groups, list) {
- if (tgi == tg)
- continue;
+ /*
+ * Ensure we don't starve existing RT tasks.
+ */
+ if (rt_bandwidth_enabled() && !runtime && tg_has_rt_tasks(tg))
+ return -EBUSY;
- total += to_ratio(ktime_to_ns(tgi->rt_bandwidth.rt_period),
- tgi->rt_bandwidth.rt_runtime);
+ total = to_ratio(period, runtime);
+
+ /*
+ * Nobody can have more than the global setting allows.
+ */
+ if (total > to_ratio(global_rt_period(), global_rt_runtime()))
+ return -EINVAL;
+
+ /*
+ * The sum of our children's runtime should not exceed our own.
+ */
+ list_for_each_entry_rcu(child, &tg->children, siblings) {
+ period = ktime_to_ns(child->rt_bandwidth.rt_period);
+ runtime = child->rt_bandwidth.rt_runtime;
+
+ if (child == d->tg) {
+ period = d->rt_period;
+ runtime = d->rt_runtime;
+ }
+
+ sum += to_ratio(period, runtime);
}
- rcu_read_unlock();
- return total + to_ratio(period, runtime) < global_ratio;
+ if (sum > total)
+ return -EINVAL;
+
+ return 0;
}
-#endif
-/* Must be called with tasklist_lock held */
-static inline int tg_has_rt_tasks(struct task_group *tg)
+static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime)
{
- struct task_struct *g, *p;
- do_each_thread(g, p) {
- if (rt_task(p) && rt_rq_of_se(&p->rt)->tg == tg)
- return 1;
- } while_each_thread(g, p);
- return 0;
+ struct rt_schedulable_data data = {
+ .tg = tg,
+ .rt_period = period,
+ .rt_runtime = runtime,
+ };
+
+ return walk_tg_tree(tg_schedulable, tg_nop, &data);
}
static int tg_set_bandwidth(struct task_group *tg,
@@ -8821,14 +8934,9 @@ static int tg_set_bandwidth(struct task_group *tg,
mutex_lock(&rt_constraints_mutex);
read_lock(&tasklist_lock);
- if (rt_runtime == 0 && tg_has_rt_tasks(tg)) {
- err = -EBUSY;
- goto unlock;
- }
- if (!__rt_schedulable(tg, rt_period, rt_runtime)) {
- err = -EINVAL;
+ err = __rt_schedulable(tg, rt_period, rt_runtime);
+ if (err)
goto unlock;
- }
spin_lock_irq(&tg->rt_bandwidth.rt_runtime_lock);
tg->rt_bandwidth.rt_period = ns_to_ktime(rt_period);
@@ -8897,16 +9005,25 @@ long sched_group_rt_period(struct task_group *tg)
static int sched_rt_global_constraints(void)
{
- struct task_group *tg = &root_task_group;
- u64 rt_runtime, rt_period;
+ u64 runtime, period;
int ret = 0;
- rt_period = ktime_to_ns(tg->rt_bandwidth.rt_period);
- rt_runtime = tg->rt_bandwidth.rt_runtime;
+ if (sysctl_sched_rt_period <= 0)
+ return -EINVAL;
+
+ runtime = global_rt_runtime();
+ period = global_rt_period();
+
+ /*
+ * Sanity check on the sysctl variables.
+ */
+ if (runtime > period && runtime != RUNTIME_INF)
+ return -EINVAL;
mutex_lock(&rt_constraints_mutex);
- if (!__rt_schedulable(tg, rt_period, rt_runtime))
- ret = -EINVAL;
+ read_lock(&tasklist_lock);
+ ret = __rt_schedulable(NULL, 0, 0);
+ read_unlock(&tasklist_lock);
mutex_unlock(&rt_constraints_mutex);
return ret;
@@ -8917,6 +9034,9 @@ static int sched_rt_global_constraints(void)
unsigned long flags;
int i;
+ if (sysctl_sched_rt_period <= 0)
+ return -EINVAL;
+
spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags);
for_each_possible_cpu(i) {
struct rt_rq *rt_rq = &cpu_rq(i)->rt;
@@ -8977,7 +9097,6 @@ cpu_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cgrp)
if (!cgrp->parent) {
/* This is early initialization for the top cgroup */
- init_task_group.css.cgroup = cgrp;
return &init_task_group.css;
}
@@ -8986,9 +9105,6 @@ cpu_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cgrp)
if (IS_ERR(tg))
return ERR_PTR(-ENOMEM);
- /* Bind the cgroup to task_group object we just created */
- tg->css.cgroup = cgrp;
-
return &tg->css;
}
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