[PATCH] mm: nommu use compound pages
Now that compound page handling is properly fixed in the VM, move nommu
over to using compound pages rather than rolling their own refcounting.
nommu vm page refcounting is broken anyway, but there is no need to have
divergent code in the core VM now, nor when it gets fixed.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: David Howells <dhowells@redhat.com>
(Needs testing, please).
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/mm/slab.c b/mm/slab.c
index f477acf..ff0ab77 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -590,6 +590,8 @@
static inline struct kmem_cache *page_get_cache(struct page *page)
{
+ if (unlikely(PageCompound(page)))
+ page = (struct page *)page_private(page);
return (struct kmem_cache *)page->lru.next;
}
@@ -600,6 +602,8 @@
static inline struct slab *page_get_slab(struct page *page)
{
+ if (unlikely(PageCompound(page)))
+ page = (struct page *)page_private(page);
return (struct slab *)page->lru.prev;
}
@@ -2412,8 +2416,11 @@
struct page *page;
/* Nasty!!!!!! I hope this is OK. */
- i = 1 << cachep->gfporder;
page = virt_to_page(objp);
+
+ i = 1;
+ if (likely(!PageCompound(page)))
+ i <<= cachep->gfporder;
do {
page_set_cache(page, cachep);
page_set_slab(page, slabp);