Merge remote-tracking branch 'tip/core/rcu' into next.2012.09.25b

Resolved conflict in kernel/sched/core.c using Peter Zijlstra's
approach from https://lkml.org/lkml/2012/9/5/585.

1 files changed, 2 insertions, 50 deletions

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 8c38b5e7ce47..1a48cdbc8631 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -5342,9 +5342,6 @@ static void migrate_tasks(unsigned int dead_cpu)
          */
         rq->stop = NULL;
 
-        /* Ensure any throttled groups are reachable by pick_next_task */
-        unthrottle_offline_cfs_rqs(rq);
-
         for ( ; ; ) {
                 /*
                  * There's this thread running, bail when that's the only
@@ -5610,15 +5607,7 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
                 break;
 
         case CPU_DEAD:
-                {
-                        struct rq *dest_rq;
-
-                        local_irq_save(flags);
-                        dest_rq = cpu_rq(smp_processor_id());
-                        raw_spin_lock(&dest_rq->lock);
-                        calc_load_migrate(rq);
-                        raw_spin_unlock_irqrestore(&dest_rq->lock, flags);
-                }
+                calc_load_migrate(rq);
                 break;
 #endif
         }
@@ -6027,11 +6016,6 @@ static void destroy_sched_domains(struct sched_domain *sd, int cpu)
  * SD_SHARE_PKG_RESOURCE set (Last Level Cache Domain) for this
  * allows us to avoid some pointer chasing select_idle_sibling().
  *
- * Iterate domains and sched_groups downward, assigning CPUs to be
- * select_idle_sibling() hw buddy.  Cross-wiring hw makes bouncing
- * due to random perturbation self canceling, ie sw buddies pull
- * their counterpart to their CPU's hw counterpart.
- *
  * Also keep a unique ID per domain (we use the first cpu number in
  * the cpumask of the domain), this allows us to quickly tell if
  * two cpus are in the same cache domain, see cpus_share_cache().
@@ -6045,40 +6029,8 @@ static void update_top_cache_domain(int cpu)
         int id = cpu;
 
         sd = highest_flag_domain(cpu, SD_SHARE_PKG_RESOURCES);
-        if (sd) {
-                struct sched_domain *tmp = sd;
-                struct sched_group *sg, *prev;
-                bool right;
-
-                /*
-                 * Traverse to first CPU in group, and count hops
-                 * to cpu from there, switching direction on each
-                 * hop, never ever pointing the last CPU rightward.
-                 */
-                do {
-                        id = cpumask_first(sched_domain_span(tmp));
-                        prev = sg = tmp->groups;
-                        right = 1;
-
-                        while (cpumask_first(sched_group_cpus(sg)) != id)
-                                sg = sg->next;
-
-                        while (!cpumask_test_cpu(cpu, sched_group_cpus(sg))) {
-                                prev = sg;
-                                sg = sg->next;
-                                right = !right;
-                        }
-
-                        /* A CPU went down, never point back to domain start. */
-                        if (right && cpumask_first(sched_group_cpus(sg->next)) == id)
-                                right = false;
-
-                        sg = right ? sg->next : prev;
-                        tmp->idle_buddy = cpumask_first(sched_group_cpus(sg));
-                } while ((tmp = tmp->child));
-
+        if (sd)
                 id = cpumask_first(sched_domain_span(sd));
-        }
 
         rcu_assign_pointer(per_cpu(sd_llc, cpu), sd);
         per_cpu(sd_llc_id, cpu) = id;