1 files changed, 9 insertions, 4 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index 6b6e0d70eb30..7ffaabd64f89 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -237,6 +237,7 @@ struct runqueue {
 
         task_t *migration_thread;
         struct list_head migration_queue;
+        int cpu;
 #endif
 
 #ifdef CONFIG_SCHEDSTATS
@@ -1654,6 +1655,9 @@ unsigned long nr_iowait(void)
 /*
  * double_rq_lock - safely lock two runqueues
  *
+ * We must take them in cpu order to match code in
+ * dependent_sleeper and wake_dependent_sleeper.
+ *
  * Note this does not disable interrupts like task_rq_lock,
  * you need to do so manually before calling.
  */
@@ -1665,7 +1669,7 @@ static void double_rq_lock(runqueue_t *rq1, runqueue_t *rq2)
                 spin_lock(&rq1->lock);
                 __acquire(rq2->lock);   /* Fake it out ;) */
         } else {
-                if (rq1 < rq2) {
+                if (rq1->cpu < rq2->cpu) {
                         spin_lock(&rq1->lock);
                         spin_lock(&rq2->lock);
                 } else {
@@ -1701,7 +1705,7 @@ static void double_lock_balance(runqueue_t *this_rq, runqueue_t *busiest)
         __acquires(this_rq->lock)
 {
         if (unlikely(!spin_trylock(&busiest->lock))) {
-                if (busiest < this_rq) {
+                if (busiest->cpu < this_rq->cpu) {
                         spin_unlock(&this_rq->lock);
                         spin_lock(&busiest->lock);
                         spin_lock(&this_rq->lock);
@@ -2869,7 +2873,7 @@ asmlinkage void __sched schedule(void)
          */
         if (likely(!current->exit_state)) {
                 if (unlikely(in_atomic())) {
-                        printk(KERN_ERR "scheduling while atomic: "
+                        printk(KERN_ERR "BUG: scheduling while atomic: "
                                 "%s/0x%08x/%d\n",
                                 current->comm, preempt_count(), current->pid);
                         dump_stack();
@@ -6029,6 +6033,7 @@ void __init sched_init(void)
                 rq->push_cpu = 0;
                 rq->migration_thread = NULL;
                 INIT_LIST_HEAD(&rq->migration_queue);
+                rq->cpu = i;
 #endif
                 atomic_set(&rq->nr_iowait, 0);
 
@@ -6069,7 +6074,7 @@ void __might_sleep(char *file, int line)
                 if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy)
                         return;
                 prev_jiffy = jiffies;
-                printk(KERN_ERR "Debug: sleeping function called from invalid"
+                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());