Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fixes from Ingo Molnar:
 "Various smaller fixlets, all over the place"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/doc: Fix generation of device-drivers
  sched: Expose preempt_schedule_irq()
  sched: Fix a trivial typo in comments
  sched: Remove unused variable in 'struct sched_domain'
  sched: Avoid NULL dereference on sd_busy
  sched: Check sched_domain before computing group power
  MAINTAINERS: Update file patterns in the lockdep and scheduler entries

4 files changed, 29 insertions, 11 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index e9c7b50c612d..4afcfb4c892b 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5267,7 +5267,7 @@ S:	Maintained
 F:      Documentation/lockdep*.txt
 F:      Documentation/lockstat.txt
 F:      include/linux/lockdep.h
-F:      kernel/lockdep*
+F:      kernel/locking/
 
 LOGICAL DISK MANAGER SUPPORT (LDM, Windows 2000/XP/Vista Dynamic Disks)
 M:      "Richard Russon (FlatCap)" <ldm@flatcap.org>
@@ -7391,7 +7391,6 @@ S:	Maintained
 F:      kernel/sched/
 F:      include/linux/sched.h
 F:      include/uapi/linux/sched.h
-F:      kernel/wait.c
 F:      include/linux/wait.h
 
 SCORE ARCHITECTURE
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 7e35d4b9e14a..768b037dfacb 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -831,8 +831,6 @@ struct sched_domain {
         unsigned int balance_interval;  /* initialise to 1. units in ms. */
         unsigned int nr_balance_failed; /* initialise to 0 */
 
-        u64 last_update;
-
         /* idle_balance() stats */
         u64 max_newidle_lb_cost;
         unsigned long next_decay_max_lb_cost;
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index c1808606ee5f..e85cda20ab2b 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2660,6 +2660,7 @@ asmlinkage void __sched notrace preempt_schedule(void)
         } while (need_resched());
 }
 EXPORT_SYMBOL(preempt_schedule);
+#endif /* CONFIG_PREEMPT */
 
 /*
  * this is the entry point to schedule() from kernel preemption
@@ -2693,8 +2694,6 @@ asmlinkage void __sched preempt_schedule_irq(void)
         exception_exit(prev_state);
 }
 
-#endif /* CONFIG_PREEMPT */
-
 int default_wake_function(wait_queue_t *curr, unsigned mode, int wake_flags,
                           void *key)
 {
@@ -4762,7 +4761,7 @@ static void rq_attach_root(struct rq *rq, struct root_domain *rd)
                 cpumask_clear_cpu(rq->cpu, old_rd->span);
 
                 /*
-                 * If we dont want to free the old_rt yet then
+                 * If we dont want to free the old_rd yet then
                  * set old_rd to NULL to skip the freeing later
                  * in this function:
                  */
@@ -4910,8 +4909,9 @@ static void update_top_cache_domain(int cpu)
         if (sd) {
                 id = cpumask_first(sched_domain_span(sd));
                 size = cpumask_weight(sched_domain_span(sd));
-                rcu_assign_pointer(per_cpu(sd_busy, cpu), sd->parent);
+                sd = sd->parent; /* sd_busy */
         }
+        rcu_assign_pointer(per_cpu(sd_busy, cpu), sd);
 
         rcu_assign_pointer(per_cpu(sd_llc, cpu), sd);
         per_cpu(sd_llc_size, cpu) = size;
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index e8b652ebe027..fd773ade1a31 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -5379,10 +5379,31 @@ void update_group_power(struct sched_domain *sd, int cpu)
                  */
 
                 for_each_cpu(cpu, sched_group_cpus(sdg)) {
-                        struct sched_group *sg = cpu_rq(cpu)->sd->groups;
+                        struct sched_group_power *sgp;
+                        struct rq *rq = cpu_rq(cpu);
 
-                        power_orig += sg->sgp->power_orig;
-                        power += sg->sgp->power;
+                        /*
+                         * build_sched_domains() -> init_sched_groups_power()
+                         * gets here before we've attached the domains to the
+                         * runqueues.
+                         *
+                         * Use power_of(), which is set irrespective of domains
+                         * in update_cpu_power().
+                         *
+                         * This avoids power/power_orig from being 0 and
+                         * causing divide-by-zero issues on boot.
+                         *
+                         * Runtime updates will correct power_orig.
+                         */
+                        if (unlikely(!rq->sd)) {
+                                power_orig += power_of(cpu);
+                                power += power_of(cpu);
+                                continue;
+                        }
+
+                        sgp = rq->sd->groups->sgp;
+                        power_orig += sgp->power_orig;
+                        power += sgp->power;
                 }
         } else  {
                 /*