]> err.no Git - linux-2.6/blobdiff - kernel/sched_fair.c
hugetlbfs: architecture header cleanup
[linux-2.6] / kernel / sched_fair.c
index 9e301a2bab6f79e0321cacbc8fb4bf2b15e809f5..89fa32b4edf27d500c3d6c644596ffc4afb881f5 100644 (file)
@@ -333,6 +333,34 @@ int sched_nr_latency_handler(struct ctl_table *table, int write,
 }
 #endif
 
+/*
+ * delta *= w / rw
+ */
+static inline unsigned long
+calc_delta_weight(unsigned long delta, struct sched_entity *se)
+{
+       for_each_sched_entity(se) {
+               delta = calc_delta_mine(delta,
+                               se->load.weight, &cfs_rq_of(se)->load);
+       }
+
+       return delta;
+}
+
+/*
+ * delta *= rw / w
+ */
+static inline unsigned long
+calc_delta_fair(unsigned long delta, struct sched_entity *se)
+{
+       for_each_sched_entity(se) {
+               delta = calc_delta_mine(delta,
+                               cfs_rq_of(se)->load.weight, &se->load);
+       }
+
+       return delta;
+}
+
 /*
  * The idea is to set a period in which each task runs once.
  *
@@ -362,47 +390,54 @@ static u64 __sched_period(unsigned long nr_running)
  */
 static u64 sched_slice(struct cfs_rq *cfs_rq, struct sched_entity *se)
 {
-       u64 slice = __sched_period(cfs_rq->nr_running);
-
-       for_each_sched_entity(se) {
-               cfs_rq = cfs_rq_of(se);
-
-               slice *= se->load.weight;
-               do_div(slice, cfs_rq->load.weight);
-       }
-
-
-       return slice;
+       return calc_delta_weight(__sched_period(cfs_rq->nr_running), se);
 }
 
 /*
  * We calculate the vruntime slice of a to be inserted task
  *
- * vs = s/w = p/rw
+ * vs = s*rw/w = p
  */
 static u64 sched_vslice_add(struct cfs_rq *cfs_rq, struct sched_entity *se)
 {
        unsigned long nr_running = cfs_rq->nr_running;
-       unsigned long weight;
-       u64 vslice;
 
        if (!se->on_rq)
                nr_running++;
 
-       vslice = __sched_period(nr_running);
+       return __sched_period(nr_running);
+}
+
+/*
+ * The goal of calc_delta_asym() is to be asymmetrically around NICE_0_LOAD, in
+ * that it favours >=0 over <0.
+ *
+ *   -20         |
+ *               |
+ *     0 --------+-------
+ *             .'
+ *    19     .'
+ *
+ */
+static unsigned long
+calc_delta_asym(unsigned long delta, struct sched_entity *se)
+{
+       struct load_weight lw = {
+               .weight = NICE_0_LOAD,
+               .inv_weight = 1UL << (WMULT_SHIFT-NICE_0_SHIFT)
+       };
 
        for_each_sched_entity(se) {
-               cfs_rq = cfs_rq_of(se);
+               struct load_weight *se_lw = &se->load;
 
-               weight = cfs_rq->load.weight;
-               if (!se->on_rq)
-                       weight += se->load.weight;
+               if (se->load.weight < NICE_0_LOAD)
+                       se_lw = &lw;
 
-               vslice *= NICE_0_LOAD;
-               do_div(vslice, weight);
+               delta = calc_delta_mine(delta,
+                               cfs_rq_of(se)->load.weight, se_lw);
        }
 
-       return vslice;
+       return delta;
 }
 
 /*
@@ -419,11 +454,7 @@ __update_curr(struct cfs_rq *cfs_rq, struct sched_entity *curr,
 
        curr->sum_exec_runtime += delta_exec;
        schedstat_add(cfs_rq, exec_clock, delta_exec);
-       delta_exec_weighted = delta_exec;
-       if (unlikely(curr->load.weight != NICE_0_LOAD)) {
-               delta_exec_weighted = calc_delta_fair(delta_exec_weighted,
-                                                       &curr->load);
-       }
+       delta_exec_weighted = calc_delta_fair(delta_exec, curr);
        curr->vruntime += delta_exec_weighted;
 }
 
@@ -533,6 +564,7 @@ account_entity_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se)
                add_cfs_task_weight(cfs_rq, se->load.weight);
        cfs_rq->nr_running++;
        se->on_rq = 1;
+       list_add(&se->group_node, &cfs_rq->tasks);
 }
 
 static void
@@ -545,6 +577,7 @@ account_entity_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se)
                add_cfs_task_weight(cfs_rq, -se->load.weight);
        cfs_rq->nr_running--;
        se->on_rq = 0;
+       list_del_init(&se->group_node);
 }
 
 static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se)
@@ -630,8 +663,7 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
                /* sleeps upto a single latency don't count. */
                if (sched_feat(NEW_FAIR_SLEEPERS)) {
                        if (sched_feat(NORMALIZED_SLEEPER))
-                               vruntime -= calc_delta_fair(sysctl_sched_latency,
-                                               &cfs_rq->load);
+                               vruntime -= calc_delta_weight(sysctl_sched_latency, se);
                        else
                                vruntime -= sysctl_sched_latency;
                }
@@ -1130,11 +1162,10 @@ static unsigned long wakeup_gran(struct sched_entity *se)
        unsigned long gran = sysctl_sched_wakeup_granularity;
 
        /*
-        * More easily preempt - nice tasks, while not making
-        * it harder for + nice tasks.
+        * More easily preempt - nice tasks, while not making it harder for
+        * + nice tasks.
         */
-       if (unlikely(se->load.weight > NICE_0_LOAD))
-               gran = calc_delta_fair(gran, &se->load);
+       gran = calc_delta_asym(sysctl_sched_wakeup_granularity, se);
 
        return gran;
 }
@@ -1289,21 +1320,24 @@ static void put_prev_task_fair(struct rq *rq, struct task_struct *prev)
  * the current task:
  */
 static struct task_struct *
-__load_balance_iterator(struct cfs_rq *cfs_rq, struct rb_node *curr)
+__load_balance_iterator(struct cfs_rq *cfs_rq, struct list_head *next)
 {
        struct task_struct *p = NULL;
        struct sched_entity *se;
 
-       if (!curr)
+       if (next == &cfs_rq->tasks)
                return NULL;
 
        /* Skip over entities that are not tasks */
        do {
-               se = rb_entry(curr, struct sched_entity, run_node);
-               curr = rb_next(curr);
-       } while (curr && !entity_is_task(se));
+               se = list_entry(next, struct sched_entity, group_node);
+               next = next->next;
+       } while (next != &cfs_rq->tasks && !entity_is_task(se));
 
-       cfs_rq->rb_load_balance_curr = curr;
+       if (next == &cfs_rq->tasks)
+               return NULL;
+
+       cfs_rq->balance_iterator = next;
 
        if (entity_is_task(se))
                p = task_of(se);
@@ -1315,14 +1349,14 @@ static struct task_struct *load_balance_start_fair(void *arg)
 {
        struct cfs_rq *cfs_rq = arg;
 
-       return __load_balance_iterator(cfs_rq, first_fair(cfs_rq));
+       return __load_balance_iterator(cfs_rq, cfs_rq->tasks.next);
 }
 
 static struct task_struct *load_balance_next_fair(void *arg)
 {
        struct cfs_rq *cfs_rq = arg;
 
-       return __load_balance_iterator(cfs_rq, cfs_rq->rb_load_balance_curr);
+       return __load_balance_iterator(cfs_rq, cfs_rq->balance_iterator);
 }
 
 static unsigned long
@@ -1577,6 +1611,30 @@ static const struct sched_class fair_sched_class = {
 };
 
 #ifdef CONFIG_SCHED_DEBUG
+static void
+print_cfs_rq_tasks(struct seq_file *m, struct cfs_rq *cfs_rq, int depth)
+{
+       struct sched_entity *se;
+
+       if (!cfs_rq)
+               return;
+
+       list_for_each_entry_rcu(se, &cfs_rq->tasks, group_node) {
+               int i;
+
+               for (i = depth; i; i--)
+                       seq_puts(m, "  ");
+
+               seq_printf(m, "%lu %s %lu\n",
+                               se->load.weight,
+                               entity_is_task(se) ? "T" : "G",
+                               calc_delta_weight(SCHED_LOAD_SCALE, se)
+                               );
+               if (!entity_is_task(se))
+                       print_cfs_rq_tasks(m, group_cfs_rq(se), depth + 1);
+       }
+}
+
 static void print_cfs_stats(struct seq_file *m, int cpu)
 {
        struct cfs_rq *cfs_rq;
@@ -1584,6 +1642,9 @@ static void print_cfs_stats(struct seq_file *m, int cpu)
        rcu_read_lock();
        for_each_leaf_cfs_rq(cpu_rq(cpu), cfs_rq)
                print_cfs_rq(m, cpu, cfs_rq);
+
+       seq_printf(m, "\nWeight tree:\n");
+       print_cfs_rq_tasks(m, &cpu_rq(cpu)->cfs, 1);
        rcu_read_unlock();
 }
 #endif