[PATCH] slab: convert cache to page mapping macros

This patch converts object cache <-> page mapping macros to static inline
functions to make the more explicit and readable.

Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Manfred Spraul <manfred@colorfullife.com>
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 8a73dcf..15d25ae 100644 (file)
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -565,14 +565,29 @@ static void **dbg_userword(kmem_cache_t *cachep, void *objp)
 #define        BREAK_GFP_ORDER_LO      0
 static int slab_break_gfp_order = BREAK_GFP_ORDER_LO;
 
-/* Macros for storing/retrieving the cachep and or slab from the
+/* Functions for storing/retrieving the cachep and or slab from the
  * global 'mem_map'. These are used to find the slab an obj belongs to.
  * With kfree(), these are used to find the cache which an obj belongs to.
  */
-#define        SET_PAGE_CACHE(pg,x)  ((pg)->lru.next = (struct list_head *)(x))
-#define        GET_PAGE_CACHE(pg)    ((kmem_cache_t *)(pg)->lru.next)
-#define        SET_PAGE_SLAB(pg,x)   ((pg)->lru.prev = (struct list_head *)(x))
-#define        GET_PAGE_SLAB(pg)     ((struct slab *)(pg)->lru.prev)
+static inline void page_set_cache(struct page *page, struct kmem_cache *cache)
+{
+       page->lru.next = (struct list_head *)cache;
+}
+
+static inline struct kmem_cache *page_get_cache(struct page *page)
+{
+       return (struct kmem_cache *)page->lru.next;
+}
+
+static inline void page_set_slab(struct page *page, struct slab *slab)
+{
+       page->lru.prev = (struct list_head *)slab;
+}
+
+static inline struct slab *page_get_slab(struct page *page)
+{
+       return (struct slab *)page->lru.prev;
+}
 
 /* These are the default caches for kmalloc. Custom caches can have other sizes. */
 struct cache_sizes malloc_sizes[] = {
@@ -1368,7 +1383,7 @@ static void check_poison_obj(kmem_cache_t *cachep, void *objp)
                /* Print some data about the neighboring objects, if they
                 * exist:
                 */
-               struct slab *slabp = GET_PAGE_SLAB(virt_to_page(objp));
+               struct slab *slabp = page_get_slab(virt_to_page(objp));
                int objnr;
 
                objnr = (objp-slabp->s_mem)/cachep->objsize;
@@ -2138,8 +2153,8 @@ static void set_slab_attr(kmem_cache_t *cachep, struct slab *slabp, void *objp)
        i = 1 << cachep->gfporder;
        page = virt_to_page(objp);
        do {
-               SET_PAGE_CACHE(page, cachep);
-               SET_PAGE_SLAB(page, slabp);
+               page_set_cache(page, cachep);
+               page_set_slab(page, slabp);
                page++;
        } while (--i);
 }
@@ -2269,14 +2284,14 @@ static void *cache_free_debugcheck(kmem_cache_t *cachep, void *objp,
        kfree_debugcheck(objp);
        page = virt_to_page(objp);
 
-       if (GET_PAGE_CACHE(page) != cachep) {
+       if (page_get_cache(page) != cachep) {
                printk(KERN_ERR "mismatch in kmem_cache_free: expected cache %p, got %p\n",
-                               GET_PAGE_CACHE(page),cachep);
+                               page_get_cache(page),cachep);
                printk(KERN_ERR "%p is %s.\n", cachep, cachep->name);
-               printk(KERN_ERR "%p is %s.\n", GET_PAGE_CACHE(page), GET_PAGE_CACHE(page)->name);
+               printk(KERN_ERR "%p is %s.\n", page_get_cache(page), page_get_cache(page)->name);
                WARN_ON(1);
        }
-       slabp = GET_PAGE_SLAB(page);
+       slabp = page_get_slab(page);
 
        if (cachep->flags & SLAB_RED_ZONE) {
                if (*dbg_redzone1(cachep, objp) != RED_ACTIVE || *dbg_redzone2(cachep, objp) != RED_ACTIVE) {
@@ -2628,7 +2643,7 @@ static void free_block(kmem_cache_t *cachep, void **objpp, int nr_objects, int n
                struct slab *slabp;
                unsigned int objnr;
 
-               slabp = GET_PAGE_SLAB(virt_to_page(objp));
+               slabp = page_get_slab(virt_to_page(objp));
                l3 = cachep->nodelists[node];
                list_del(&slabp->list);
                objnr = (objp - slabp->s_mem) / cachep->objsize;
@@ -2744,7 +2759,7 @@ static inline void __cache_free(kmem_cache_t *cachep, void *objp)
 #ifdef CONFIG_NUMA
        {
                struct slab *slabp;
-               slabp = GET_PAGE_SLAB(virt_to_page(objp));
+               slabp = page_get_slab(virt_to_page(objp));
                if (unlikely(slabp->nodeid != numa_node_id())) {
                        struct array_cache *alien = NULL;
                        int nodeid = slabp->nodeid;
@@ -2830,7 +2845,7 @@ int fastcall kmem_ptr_validate(kmem_cache_t *cachep, void *ptr)
        page = virt_to_page(ptr);
        if (unlikely(!PageSlab(page)))
                goto out;
-       if (unlikely(GET_PAGE_CACHE(page) != cachep))
+       if (unlikely(page_get_cache(page) != cachep))
                goto out;
        return 1;
 out:
@@ -3026,7 +3041,7 @@ void kfree(const void *objp)
                return;
        local_irq_save(flags);
        kfree_debugcheck(objp);
-       c = GET_PAGE_CACHE(virt_to_page(objp));
+       c = page_get_cache(virt_to_page(objp));
        __cache_free(c, (void*)objp);
        local_irq_restore(flags);
 }
@@ -3596,7 +3611,7 @@ unsigned int ksize(const void *objp)
        if (unlikely(objp == NULL))
                return 0;
 
-       return obj_reallen(GET_PAGE_CACHE(virt_to_page(objp)));
+       return obj_reallen(page_get_cache(virt_to_page(objp)));
 }