Add virt_to_head_page and consolidate code in slab and slub

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 5 deletions

diff --git a/mm/slab.c b/mm/slab.c
index f4b2e22b5c61..3e984afc199c 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -614,20 +614,19 @@ static inline void page_set_slab(struct page *page, struct slab *slab)
 
 static inline struct slab *page_get_slab(struct page *page)
 {
-        page = compound_head(page);
         BUG_ON(!PageSlab(page));
         return (struct slab *)page->lru.prev;
 }
 
 static inline struct kmem_cache *virt_to_cache(const void *obj)
 {
-        struct page *page = virt_to_page(obj);
+        struct page *page = virt_to_head_page(obj);
         return page_get_cache(page);
 }
 
 static inline struct slab *virt_to_slab(const void *obj)
 {
-        struct page *page = virt_to_page(obj);
+        struct page *page = virt_to_head_page(obj);
         return page_get_slab(page);
 }
 
@@ -2876,7 +2875,7 @@ static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp,
 
         objp -= obj_offset(cachep);
         kfree_debugcheck(objp);
-        page = virt_to_page(objp);
+        page = virt_to_head_page(objp);
 
         slabp = page_get_slab(page);
 
@@ -3100,7 +3099,7 @@ static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep,
                 struct slab *slabp;
                 unsigned objnr;
 
-                slabp = page_get_slab(virt_to_page(objp));
+                slabp = page_get_slab(virt_to_head_page(objp));
                 objnr = (unsigned)(objp - slabp->s_mem) / cachep->buffer_size;
                 slab_bufctl(slabp)[objnr] = BUFCTL_ACTIVE;
         }