Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6

[deliverable/linux.git] / kernel / sched.c

diff --git a/kernel/sched.c b/kernel/sched.c
index 5fecbbba12acff129654b7f0ab67c2cadabe6b4e..b533d6db78aab0afd5840627e0b568797fb12fbd 100644 (file)
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1587,6 +1587,7 @@ static void __sched_fork(struct task_struct *p)
        p->se.wait_start_fair           = 0;
        p->se.exec_start                = 0;
        p->se.sum_exec_runtime          = 0;
+       p->se.prev_sum_exec_runtime     = 0;
        p->se.delta_exec                = 0;
        p->se.delta_fair_run            = 0;
        p->se.delta_fair_sleep          = 0;
@@ -2180,12 +2181,6 @@ int can_migrate_task(struct task_struct *p, struct rq *rq, int this_cpu,
        if (task_running(rq, p))
                return 0;
 
-       /*
-        * Aggressive migration if too many balance attempts have failed:
-        */
-       if (sd->nr_balance_failed > sd->cache_nice_tries)
-               return 1;
-
        return 1;
 }
 
@@ -2517,7 +2512,7 @@ group_next:
         * a think about bumping its value to force at least one task to be
         * moved
         */
-       if (*imbalance + SCHED_LOAD_SCALE_FUZZ < busiest_load_per_task/2) {
+       if (*imbalance + SCHED_LOAD_SCALE_FUZZ < busiest_load_per_task) {
                unsigned long tmp, pwr_now, pwr_move;
                unsigned int imbn;
 
@@ -3043,6 +3038,7 @@ static inline void rebalance_domains(int cpu, enum cpu_idle_type idle)
        struct sched_domain *sd;
        /* Earliest time when we have to do rebalance again */
        unsigned long next_balance = jiffies + 60*HZ;
+       int update_next_balance = 0;
 
        for_each_domain(cpu, sd) {
                if (!(sd->flags & SD_LOAD_BALANCE))
@@ -3079,8 +3075,10 @@ static inline void rebalance_domains(int cpu, enum cpu_idle_type idle)
                if (sd->flags & SD_SERIALIZE)
                        spin_unlock(&balancing);
 out:
-               if (time_after(next_balance, sd->last_balance + interval))
+               if (time_after(next_balance, sd->last_balance + interval)) {
                        next_balance = sd->last_balance + interval;
+                       update_next_balance = 1;
+               }
 
                /*
                 * Stop the load balance at this level. There is another
@@ -3090,7 +3088,14 @@ out:
                if (!balance)
                        break;
        }
-       rq->next_balance = next_balance;
+
+       /*
+        * next_balance will be updated only when there is a need.
+        * When the cpu is attached to null domain for ex, it will not be
+        * updated.
+        */
+       if (likely(update_next_balance))
+               rq->next_balance = next_balance;
 }
 
 /*
@@ -4907,14 +4912,18 @@ cpumask_t nohz_cpu_mask = CPU_MASK_NONE;
 static inline void sched_init_granularity(void)
 {
        unsigned int factor = 1 + ilog2(num_online_cpus());
-       const unsigned long gran_limit = 100000000;
+       const unsigned long limit = 100000000;
+
+       sysctl_sched_min_granularity *= factor;
+       if (sysctl_sched_min_granularity > limit)
+               sysctl_sched_min_granularity = limit;
 
-       sysctl_sched_granularity *= factor;
-       if (sysctl_sched_granularity > gran_limit)
-               sysctl_sched_granularity = gran_limit;
+       sysctl_sched_latency *= factor;
+       if (sysctl_sched_latency > limit)
+               sysctl_sched_latency = limit;
 
-       sysctl_sched_runtime_limit = sysctl_sched_granularity * 4;
-       sysctl_sched_wakeup_granularity = sysctl_sched_granularity / 2;
+       sysctl_sched_runtime_limit = sysctl_sched_latency;
+       sysctl_sched_wakeup_granularity = sysctl_sched_min_granularity / 2;
 }
 
 #ifdef CONFIG_SMP