[PATCH 14/17] slub: Add slab_page_lock

[Matthew Wilcox (Oracle)]

Allow lockdep to track slub's page bit spin lock.

Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
 mm/slub.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/mm/slub.c b/mm/slub.c
index 9c0e26ddf300..2ed2abe080ac 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -346,19 +346,21 @@ static inline unsigned int oo_objects(struct kmem_cache_order_objects x)
 	return x.x & OO_MASK;
 }
 
+static DEFINE_SPLIT_LOCK(slab_page_lock);
+
 /*
  * Per slab locking using the pagelock
  */
 static __always_inline void slab_lock(struct page *page)
 {
 	VM_BUG_ON_PAGE(PageTail(page), page);
-	bit_spin_lock(PG_locked, &page->flags);
+	bit_spin_lock(PG_locked, &page->flags, &slab_page_lock);
 }
 
 static __always_inline void slab_unlock(struct page *page)
 {
 	VM_BUG_ON_PAGE(PageTail(page), page);
-	__bit_spin_unlock(PG_locked, &page->flags);
+	__bit_spin_unlock(PG_locked, &page->flags, &slab_page_lock);
 }
 
 /* Interrupts must be disabled (for the fallback code to work right) */
-- 
2.30.2