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

Pull core locking changes from Ingo Molnar:
 "The biggest changes:

   - add lockdep support for seqcount/seqlocks structures, this
     unearthed both bugs and required extra annotation.

   - move the various kernel locking primitives to the new
     kernel/locking/ directory"

* 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits)
  block: Use u64_stats_init() to initialize seqcounts
  locking/lockdep: Mark __lockdep_count_forward_deps() as static
  lockdep/proc: Fix lock-time avg computation
  locking/doc: Update references to kernel/mutex.c
  ipv6: Fix possible ipv6 seqlock deadlock
  cpuset: Fix potential deadlock w/ set_mems_allowed
  seqcount: Add lockdep functionality to seqcount/seqlock structures
  net: Explicitly initialize u64_stats_sync structures for lockdep
  locking: Move the percpu-rwsem code to kernel/locking/
  locking: Move the lglocks code to kernel/locking/
  locking: Move the rwsem code to kernel/locking/
  locking: Move the rtmutex code to kernel/locking/
  locking: Move the semaphore core to kernel/locking/
  locking: Move the spinlock code to kernel/locking/
  locking: Move the lockdep code to kernel/locking/
  locking: Move the mutex code to kernel/locking/
  hung_task debugging: Add tracepoint to report the hang
  x86/locking/kconfig: Update paravirt spinlock Kconfig description
  lockstat: Report avg wait and hold times
  lockdep, x86/alternatives: Drop ancient lockdep fixup message
  ...

3 files changed, 45 insertions, 0 deletions

diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index ae6969a7ffd4..1610b22edf09 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -402,6 +402,11 @@ struct request_list *__blk_queue_next_rl(struct request_list *rl,
 #define blk_queue_for_each_rl(rl, q)    \
         for ((rl) = &(q)->root_rl; (rl); (rl) = __blk_queue_next_rl((rl), (q)))
 
+static inline void blkg_stat_init(struct blkg_stat *stat)
+{
+        u64_stats_init(&stat->syncp);
+}
+
 /**
  * blkg_stat_add - add a value to a blkg_stat
  * @stat: target blkg_stat
@@ -458,6 +463,11 @@ static inline void blkg_stat_merge(struct blkg_stat *to, struct blkg_stat *from)
         blkg_stat_add(to, blkg_stat_read(from));
 }
 
+static inline void blkg_rwstat_init(struct blkg_rwstat *rwstat)
+{
+        u64_stats_init(&rwstat->syncp);
+}
+
 /**
  * blkg_rwstat_add - add a value to a blkg_rwstat
  * @rwstat: target blkg_rwstat
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 8331aba9426f..06534049afba 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -256,6 +256,12 @@ static struct throtl_data *sq_to_td(struct throtl_service_queue *sq)
         }                                                               \
 } while (0)
 
+static void tg_stats_init(struct tg_stats_cpu *tg_stats)
+{
+        blkg_rwstat_init(&tg_stats->service_bytes);
+        blkg_rwstat_init(&tg_stats->serviced);
+}
+
 /*
  * Worker for allocating per cpu stat for tgs. This is scheduled on the
  * system_wq once there are some groups on the alloc_list waiting for
@@ -269,12 +275,16 @@ static void tg_stats_alloc_fn(struct work_struct *work)
 
 alloc_stats:
         if (!stats_cpu) {
+                int cpu;
+
                 stats_cpu = alloc_percpu(struct tg_stats_cpu);
                 if (!stats_cpu) {
                         /* allocation failed, try again after some time */
                         schedule_delayed_work(dwork, msecs_to_jiffies(10));
                         return;
                 }
+                for_each_possible_cpu(cpu)
+                        tg_stats_init(per_cpu_ptr(stats_cpu, cpu));
         }
 
         spin_lock_irq(&tg_stats_alloc_lock);
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 434944cbd761..4d5cec1ad80d 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -1508,6 +1508,29 @@ static void cfq_init_cfqg_base(struct cfq_group *cfqg)
 }
 
 #ifdef CONFIG_CFQ_GROUP_IOSCHED
+static void cfqg_stats_init(struct cfqg_stats *stats)
+{
+        blkg_rwstat_init(&stats->service_bytes);
+        blkg_rwstat_init(&stats->serviced);
+        blkg_rwstat_init(&stats->merged);
+        blkg_rwstat_init(&stats->service_time);
+        blkg_rwstat_init(&stats->wait_time);
+        blkg_rwstat_init(&stats->queued);
+
+        blkg_stat_init(&stats->sectors);
+        blkg_stat_init(&stats->time);
+
+#ifdef CONFIG_DEBUG_BLK_CGROUP
+        blkg_stat_init(&stats->unaccounted_time);
+        blkg_stat_init(&stats->avg_queue_size_sum);
+        blkg_stat_init(&stats->avg_queue_size_samples);
+        blkg_stat_init(&stats->dequeue);
+        blkg_stat_init(&stats->group_wait_time);
+        blkg_stat_init(&stats->idle_time);
+        blkg_stat_init(&stats->empty_time);
+#endif
+}
+
 static void cfq_pd_init(struct blkcg_gq *blkg)
 {
         struct cfq_group *cfqg = blkg_to_cfqg(blkg);
@@ -1515,6 +1538,8 @@ static void cfq_pd_init(struct blkcg_gq *blkg)
         cfq_init_cfqg_base(cfqg);
         cfqg->weight = blkg->blkcg->cfq_weight;
         cfqg->leaf_weight = blkg->blkcg->cfq_leaf_weight;
+        cfqg_stats_init(&cfqg->stats);
+        cfqg_stats_init(&cfqg->dead_stats);
 }
 
 static void cfq_pd_offline(struct blkcg_gq *blkg)