[PATCH] sched: add option to serialize load balancing

[linux-2.6-omap-h63xx.git] / kernel / sched.c

diff --git a/kernel/sched.c b/kernel/sched.c
index 0a4a26b21f69e275a3d1e0e074f2c0c10b346a38..2b2b780939c9818013324f4c5ad65af10bd5ed35 100644 (file)
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2880,6 +2880,7 @@ static void update_load(struct rq *this_rq)
  *
  * Balancing parameters are set up in arch_init_sched_domains.
  */
+static DEFINE_SPINLOCK(balancing);
 
 static void run_rebalance_domains(struct softirq_action *h)
 {
@@ -2909,6 +2910,11 @@ static void run_rebalance_domains(struct softirq_action *h)
                if (unlikely(!interval))
                        interval = 1;
 
+               if (sd->flags & SD_SERIALIZE) {
+                       if (!spin_trylock(&balancing))
+                               goto out;
+               }
+
                if (time_after_eq(jiffies, sd->last_balance + interval)) {
                        if (load_balance(this_cpu, this_rq, sd, idle)) {
                                /*
@@ -2920,6 +2926,9 @@ static void run_rebalance_domains(struct softirq_action *h)
                        }
                        sd->last_balance = jiffies;
                }
+               if (sd->flags & SD_SERIALIZE)
+                       spin_unlock(&balancing);
+out:
                if (time_after(next_balance, sd->last_balance + interval))
                        next_balance = sd->last_balance + interval;
        }