--- a/mm/slub.c~mm-slub-make-slab_lock-disable-irqs-with-preempt_rt
+++ a/mm/slub.c
@@ -359,25 +359,44 @@ static inline unsigned int oo_objects(st
 /*
  * Per slab locking using the pagelock
  */
-static __always_inline void slab_lock(struct page *page)
+static __always_inline void __slab_lock(struct page *page)
 {
 	VM_BUG_ON_PAGE(PageTail(page), page);
 	bit_spin_lock(PG_locked, &page->flags);
 }
 
-static __always_inline void slab_unlock(struct page *page)
+static __always_inline void __slab_unlock(struct page *page)
 {
 	VM_BUG_ON_PAGE(PageTail(page), page);
 	__bit_spin_unlock(PG_locked, &page->flags);
 }
 
-/* Interrupts must be disabled (for the fallback code to work right) */
+static __always_inline void slab_lock(struct page *page, unsigned long *flags)
+{
+	if (IS_ENABLED(CONFIG_PREEMPT_RT))
+		local_irq_save(*flags);
+	__slab_lock(page);
+}
+
+static __always_inline void slab_unlock(struct page *page, unsigned long *flags)
+{
+	__slab_unlock(page);
+	if (IS_ENABLED(CONFIG_PREEMPT_RT))
+		local_irq_restore(*flags);
+}
+
+/*
+ * Interrupts must be disabled (for the fallback code to work right), typically
+ * by an _irqsave() lock variant. Except on PREEMPT_RT where locks are different
+ * so we disable interrupts as part of slab_[un]lock().
+ */
 static inline bool __cmpxchg_double_slab(struct kmem_cache *s, struct page *page,
 		void *freelist_old, unsigned long counters_old,
 		void *freelist_new, unsigned long counters_new,
 		const char *n)
 {
-	VM_BUG_ON(!irqs_disabled());
+	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
+		lockdep_assert_irqs_disabled();
 #if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && \
     defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE)
 	if (s->flags & __CMPXCHG_DOUBLE) {
@@ -388,15 +407,18 @@ static inline bool __cmpxchg_double_slab
 	} else
 #endif
 	{
-		slab_lock(page);
+		/* init to 0 to prevent spurious warnings */
+		unsigned long flags = 0;
+
+		slab_lock(page, &flags);
 		if (page->freelist == freelist_old &&
 					page->counters == counters_old) {
 			page->freelist = freelist_new;
 			page->counters = counters_new;
-			slab_unlock(page);
+			slab_unlock(page, &flags);
 			return true;
 		}
-		slab_unlock(page);
+		slab_unlock(page, &flags);
 	}
 
 	cpu_relax();
@@ -427,16 +449,16 @@ static inline bool cmpxchg_double_slab(s
 		unsigned long flags;
 
 		local_irq_save(flags);
-		slab_lock(page);
+		__slab_lock(page);
 		if (page->freelist == freelist_old &&
 					page->counters == counters_old) {
 			page->freelist = freelist_new;
 			page->counters = counters_new;
-			slab_unlock(page);
+			__slab_unlock(page);
 			local_irq_restore(flags);
 			return true;
 		}
-		slab_unlock(page);
+		__slab_unlock(page);
 		local_irq_restore(flags);
 	}
 
@@ -1269,11 +1291,11 @@ static noinline int free_debug_processin
 	struct kmem_cache_node *n = get_node(s, page_to_nid(page));
 	void *object = head;
 	int cnt = 0;
-	unsigned long flags;
+	unsigned long flags, flags2;
 	int ret = 0;
 
 	spin_lock_irqsave(&n->list_lock, flags);
-	slab_lock(page);
+	slab_lock(page, &flags2);
 
 	if (s->flags & SLAB_CONSISTENCY_CHECKS) {
 		if (!check_slab(s, page))
@@ -1306,7 +1328,7 @@ out:
 		slab_err(s, page, "Bulk freelist count(%d) invalid(%d)\n",
 			 bulk_cnt, cnt);
 
-	slab_unlock(page);
+	slab_unlock(page, &flags2);
 	spin_unlock_irqrestore(&n->list_lock, flags);
 	if (!ret)
 		slab_fix(s, "Object at 0x%p not freed", object);
@@ -4087,11 +4109,12 @@ static void list_slab_objects(struct kme
 {
 #ifdef CONFIG_SLUB_DEBUG
 	void *addr = page_address(page);
+	unsigned long flags;
 	unsigned long *map;
 	void *p;
 
 	slab_err(s, page, text, s->name);
-	slab_lock(page);
+	slab_lock(page, &flags);
 
 	map = get_map(s, page);
 	for_each_object(p, s, addr, page->objects) {
@@ -4102,7 +4125,7 @@ static void list_slab_objects(struct kme
 		}
 	}
 	put_map(map);
-	slab_unlock(page);
+	slab_unlock(page, &flags);
 #endif
 }
 
@@ -4834,8 +4857,9 @@ static void validate_slab(struct kmem_ca
 {
 	void *p;
 	void *addr = page_address(page);
+	unsigned long flags;
 
-	slab_lock(page);
+	slab_lock(page, &flags);
 
 	if (!check_slab(s, page) || !on_freelist(s, page, NULL))
 		goto unlock;
@@ -4850,7 +4874,7 @@ static void validate_slab(struct kmem_ca
 			break;
 	}
 unlock:
-	slab_unlock(page);
+	slab_unlock(page, &flags);
 }
 
 static int validate_slab_node(struct kmem_cache *s,
