Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu

Pull RCU changes from Paul E. McKenney:

- Convert RCU's BUG_ON() and similar calls to WARN_ON() and similar.

- Replace calls of RCU-bh and RCU-sched update-side functions
  to their vanilla RCU counterparts.  This series is a step
  towards complete removal of the RCU-bh and RCU-sched update-side
  functions.

  ( Note that some of these conversions are going upstream via their
    respective maintainers. )

- Documentation updates, including a number of flavor-consolidation
  updates from Joel Fernandes.

- Miscellaneous fixes.

- Automate generation of the initrd filesystem used for
  rcutorture testing.

- Convert spin_is_locked() assertions to instead use lockdep.

  ( Note that some of these conversions are going upstream via their
    respective maintainers. )

- SRCU updates, especially including a fix from Dennis Krein
  for a bag-on-head-class bug.

- RCU torture-test updates.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

mm/khugepaged.c

@@ -1225,7 +1225,7 @@ static void collect_mm_slot(struct mm_slot *mm_slot)
 {
 	struct mm_struct *mm = mm_slot->mm;
 
-	VM_BUG_ON(NR_CPUS != 1 && !spin_is_locked(&khugepaged_mm_lock));
+	lockdep_assert_held(&khugepaged_mm_lock);
 
 	if (khugepaged_test_exit(mm)) {
 		/* free mm_slot */
@@ -1653,7 +1653,7 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages,
 	int progress = 0;
 
 	VM_BUG_ON(!pages);
-	VM_BUG_ON(NR_CPUS != 1 && !spin_is_locked(&khugepaged_mm_lock));
+	lockdep_assert_held(&khugepaged_mm_lock);
 
 	if (khugepaged_scan.mm_slot)
 		mm_slot = khugepaged_scan.mm_slot;

mm/mmu_gather.c

@@ -199,7 +199,7 @@ void tlb_table_flush(struct mmu_gather *tlb)
 
 	if (*batch) {
 		tlb_table_invalidate(tlb);
-		call_rcu_sched(&(*batch)->rcu, tlb_remove_table_rcu);
+		call_rcu(&(*batch)->rcu, tlb_remove_table_rcu);
 		*batch = NULL;
 	}
 }

mm/slab.c

@@ -962,10 +962,10 @@ static int setup_kmem_cache_node(struct kmem_cache *cachep,
 	 * To protect lockless access to n->shared during irq disabled context.
 	 * If n->shared isn't NULL in irq disabled context, accessing to it is
 	 * guaranteed to be valid until irq is re-enabled, because it will be
-	 * freed after synchronize_sched().
+	 * freed after synchronize_rcu().
 	 */
 	if (old_shared && force_change)
-		synchronize_sched();
+		synchronize_rcu();
 
 fail:
 	kfree(old_shared);

mm/slab_common.c

@@ -724,7 +724,7 @@ void slab_deactivate_memcg_cache_rcu_sched(struct kmem_cache *s,
 	css_get(&s->memcg_params.memcg->css);
 
 	s->memcg_params.deact_fn = deact_fn;
-	call_rcu_sched(&s->memcg_params.deact_rcu_head, kmemcg_deactivate_rcufn);
+	call_rcu(&s->memcg_params.deact_rcu_head, kmemcg_deactivate_rcufn);
 }
 
 void memcg_deactivate_kmem_caches(struct mem_cgroup *memcg)
@@ -839,11 +839,11 @@ static void flush_memcg_workqueue(struct kmem_cache *s)
 	mutex_unlock(&slab_mutex);
 
 	/*
-	 * SLUB deactivates the kmem_caches through call_rcu_sched. Make
+	 * SLUB deactivates the kmem_caches through call_rcu. Make
 	 * sure all registered rcu callbacks have been invoked.
 	 */
 	if (IS_ENABLED(CONFIG_SLUB))
-		rcu_barrier_sched();
+		rcu_barrier();
 
 	/*
 	 * SLAB and SLUB create memcg kmem_caches through workqueue and SLUB

mm/swap.c

@@ -823,8 +823,7 @@ void lru_add_page_tail(struct page *page, struct page *page_tail,
 	VM_BUG_ON_PAGE(!PageHead(page), page);
 	VM_BUG_ON_PAGE(PageCompound(page_tail), page);
 	VM_BUG_ON_PAGE(PageLRU(page_tail), page);
-	VM_BUG_ON(NR_CPUS != 1 &&
-		  !spin_is_locked(&lruvec_pgdat(lruvec)->lru_lock));
+	lockdep_assert_held(&lruvec_pgdat(lruvec)->lru_lock);
 
 	if (!list)
 		SetPageLRU(page_tail);