relayfs: support larger relay buffer

[safe/jmp/linux-2.6] / kernel / sched_rt.c

diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 8bc1761..c2730a5 100644 (file)
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -62,7 +62,12 @@ static inline u64 sched_rt_runtime(struct rt_rq *rt_rq)
        if (!rt_rq->tg)
                return RUNTIME_INF;
 
-       return rt_rq->tg->rt_bandwidth.rt_runtime;
+       return rt_rq->rt_runtime;
+}
+
+static inline u64 sched_rt_period(struct rt_rq *rt_rq)
+{
+       return ktime_to_ns(rt_rq->tg->rt_bandwidth.rt_period);
 }
 
 #define for_each_leaf_rt_rq(rt_rq, rq) \
@@ -145,11 +150,21 @@ struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu)
        return container_of(rt_b, struct task_group, rt_bandwidth)->rt_rq[cpu];
 }
 
+static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq)
+{
+       return &rt_rq->tg->rt_bandwidth;
+}
+
 #else
 
 static inline u64 sched_rt_runtime(struct rt_rq *rt_rq)
 {
-       return def_rt_bandwidth.rt_runtime;
+       return rt_rq->rt_runtime;
+}
+
+static inline u64 sched_rt_period(struct rt_rq *rt_rq)
+{
+       return ktime_to_ns(def_rt_bandwidth.rt_period);
 }
 
 #define for_each_leaf_rt_rq(rt_rq, rq) \
@@ -200,6 +215,11 @@ struct rt_rq *sched_rt_period_rt_rq(struct rt_bandwidth *rt_b, int cpu)
        return &cpu_rq(cpu)->rt;
 }
 
+static inline struct rt_bandwidth *sched_rt_bandwidth(struct rt_rq *rt_rq)
+{
+       return &def_rt_bandwidth;
+}
+
 #endif
 
 static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun)
@@ -218,8 +238,10 @@ static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun)
 
                spin_lock(&rq->lock);
                if (rt_rq->rt_time) {
-                       u64 runtime = rt_b->rt_runtime;
+                       u64 runtime;
 
+                       spin_lock(&rt_rq->rt_runtime_lock);
+                       runtime = rt_rq->rt_runtime;
                        rt_rq->rt_time -= min(rt_rq->rt_time, overrun*runtime);
                        if (rt_rq->rt_throttled && rt_rq->rt_time < runtime) {
                                rt_rq->rt_throttled = 0;
@@ -227,6 +249,7 @@ static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun)
                        }
                        if (rt_rq->rt_time || rt_rq->rt_nr_running)
                                idle = 0;
+                       spin_unlock(&rt_rq->rt_runtime_lock);
                }
 
                if (enqueue)
@@ -237,6 +260,47 @@ static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun)
        return idle;
 }
 
+#ifdef CONFIG_SMP
+static int balance_runtime(struct rt_rq *rt_rq)
+{
+       struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq);
+       struct root_domain *rd = cpu_rq(smp_processor_id())->rd;
+       int i, weight, more = 0;
+       u64 rt_period;
+
+       weight = cpus_weight(rd->span);
+
+       spin_lock(&rt_b->rt_runtime_lock);
+       rt_period = ktime_to_ns(rt_b->rt_period);
+       for_each_cpu_mask(i, rd->span) {
+               struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i);
+               s64 diff;
+
+               if (iter == rt_rq)
+                       continue;
+
+               spin_lock(&iter->rt_runtime_lock);
+               diff = iter->rt_runtime - iter->rt_time;
+               if (diff > 0) {
+                       do_div(diff, weight);
+                       if (rt_rq->rt_runtime + diff > rt_period)
+                               diff = rt_period - rt_rq->rt_runtime;
+                       iter->rt_runtime -= diff;
+                       rt_rq->rt_runtime += diff;
+                       more = 1;
+                       if (rt_rq->rt_runtime == rt_period) {
+                               spin_unlock(&iter->rt_runtime_lock);
+                               break;
+                       }
+               }
+               spin_unlock(&iter->rt_runtime_lock);
+       }
+       spin_unlock(&rt_b->rt_runtime_lock);
+
+       return more;
+}
+#endif
+
 static inline int rt_se_prio(struct sched_rt_entity *rt_se)
 {
 #ifdef CONFIG_RT_GROUP_SCHED
@@ -259,6 +323,22 @@ static int sched_rt_runtime_exceeded(struct rt_rq *rt_rq)
        if (rt_rq->rt_throttled)
                return rt_rq_throttled(rt_rq);
 
+       if (sched_rt_runtime(rt_rq) >= sched_rt_period(rt_rq))
+               return 0;
+
+#ifdef CONFIG_SMP
+       if (rt_rq->rt_time > runtime) {
+               int more;
+
+               spin_unlock(&rt_rq->rt_runtime_lock);
+               more = balance_runtime(rt_rq);
+               spin_lock(&rt_rq->rt_runtime_lock);
+
+               if (more)
+                       runtime = sched_rt_runtime(rt_rq);
+       }
+#endif
+
        if (rt_rq->rt_time > runtime) {
                rt_rq->rt_throttled = 1;
                if (rt_rq_throttled(rt_rq)) {
@@ -294,9 +374,15 @@ static void update_curr_rt(struct rq *rq)
        curr->se.exec_start = rq->clock;
        cpuacct_charge(curr, delta_exec);
 
-       rt_rq->rt_time += delta_exec;
-       if (sched_rt_runtime_exceeded(rt_rq))
-               resched_task(curr);
+       for_each_sched_rt_entity(rt_se) {
+               rt_rq = rt_rq_of_se(rt_se);
+
+               spin_lock(&rt_rq->rt_runtime_lock);
+               rt_rq->rt_time += delta_exec;
+               if (sched_rt_runtime_exceeded(rt_rq))
+                       resched_task(curr);
+               spin_unlock(&rt_rq->rt_runtime_lock);
+       }
 }
 
 static inline
@@ -393,27 +479,21 @@ static void dequeue_rt_entity(struct sched_rt_entity *rt_se)
 /*
  * Because the prio of an upper entry depends on the lower
  * entries, we must remove entries top - down.
- *
- * XXX: O(1/2 h^2) because we can only walk up, not down the chain.
- *      doesn't matter much for now, as h=2 for GROUP_SCHED.
  */
 static void dequeue_rt_stack(struct task_struct *p)
 {
-       struct sched_rt_entity *rt_se, *top_se;
+       struct sched_rt_entity *rt_se, *back = NULL;
 
-       /*
-        * dequeue all, top - down.
-        */
-       do {
-               rt_se = &p->rt;
-               top_se = NULL;
-               for_each_sched_rt_entity(rt_se) {
-                       if (on_rt_rq(rt_se))
-                               top_se = rt_se;
-               }
-               if (top_se)
-                       dequeue_rt_entity(top_se);
-       } while (top_se);
+       rt_se = &p->rt;
+       for_each_sched_rt_entity(rt_se) {
+               rt_se->back = back;
+               back = rt_se;
+       }
+
+       for (rt_se = back; rt_se; rt_se = rt_se->back) {
+               if (on_rt_rq(rt_se))
+                       dequeue_rt_entity(rt_se);
+       }
 }
 
 /*
@@ -433,6 +513,8 @@ static void enqueue_task_rt(struct rq *rq, struct task_struct *p, int wakeup)
         */
        for_each_sched_rt_entity(rt_se)
                enqueue_rt_entity(rt_se);
+
+       inc_cpu_load(rq, p->se.load.weight);
 }
 
 static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int sleep)
@@ -452,6 +534,8 @@ static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int sleep)
                if (rt_rq && rt_rq->rt_nr_running)
                        enqueue_rt_entity(rt_se);
        }
+
+       dec_cpu_load(rq, p->se.load.weight);
 }
 
 /*
@@ -1041,7 +1125,8 @@ move_one_task_rt(struct rq *this_rq, int this_cpu, struct rq *busiest,
        return 0;
 }
 
-static void set_cpus_allowed_rt(struct task_struct *p, cpumask_t *new_mask)
+static void set_cpus_allowed_rt(struct task_struct *p,
+                               const cpumask_t *new_mask)
 {
        int weight = cpus_weight(*new_mask);