[PATCH] slab: page mapping cleanup
Clean up slab allocator page mapping a bit. The memory allocated for a
slab is physically contiguous so it is okay to assume struct pages are too
so kill the long-standing comment. Furthermore, rename set_slab_attr to
slab_map_pages and add a comment explaining why its needed.
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
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 bf05ea9..a94cf0f 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -2499,23 +2499,28 @@
slabp->inuse--;
}
-static void set_slab_attr(struct kmem_cache *cachep, struct slab *slabp,
- void *objp)
+/*
+ * Map pages beginning at addr to the given cache and slab. This is required
+ * for the slab allocator to be able to lookup the cache and slab of a
+ * virtual address for kfree, ksize, kmem_ptr_validate, and slab debugging.
+ */
+static void slab_map_pages(struct kmem_cache *cache, struct slab *slab,
+ void *addr)
{
- int i;
+ int nr_pages;
struct page *page;
- /* Nasty!!!!!! I hope this is OK. */
- page = virt_to_page(objp);
+ page = virt_to_page(addr);
- i = 1;
+ nr_pages = 1;
if (likely(!PageCompound(page)))
- i <<= cachep->gfporder;
+ nr_pages <<= cache->gfporder;
+
do {
- page_set_cache(page, cachep);
- page_set_slab(page, slabp);
+ page_set_cache(page, cache);
+ page_set_slab(page, slab);
page++;
- } while (--i);
+ } while (--nr_pages);
}
/*
@@ -2587,7 +2592,7 @@
goto opps1;
slabp->nodeid = nodeid;
- set_slab_attr(cachep, slabp, objp);
+ slab_map_pages(cachep, slabp, objp);
cache_init_objs(cachep, slabp, ctor_flags);