slub: prefetch next freelist pointer in slab_alloc()

[pandora-kernel.git] / mm / slub.c

diff --git a/mm/slub.c b/mm/slub.c
index 6a4c2fb..2ed452b 100644 (file)
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -269,6 +269,11 @@ static inline void *get_freepointer(struct kmem_cache *s, void *object)
        return *(void **)(object + s->offset);
 }
 
+static void prefetch_freepointer(const struct kmem_cache *s, void *object)
+{
+       prefetch(object + s->offset);
+}
+
 static inline void *get_freepointer_safe(struct kmem_cache *s, void *object)
 {
        void *p;
@@ -2310,6 +2315,8 @@ redo:
                object = __slab_alloc(s, gfpflags, node, addr, c);
 
        else {
+               void *next_object = get_freepointer_safe(s, object);
+
                /*
                 * The cmpxchg will only match if there was no additional
                 * operation and if we are on the right processor.
@@ -2325,11 +2332,12 @@ redo:
                if (unlikely(!irqsafe_cpu_cmpxchg_double(
                                s->cpu_slab->freelist, s->cpu_slab->tid,
                                object, tid,
-                               get_freepointer_safe(s, object), next_tid(tid)))) {
+                               next_object, next_tid(tid)))) {
 
                        note_cmpxchg_failure("slab_alloc", s, tid);
                        goto redo;
                }
+               prefetch_freepointer(s, next_object);
                stat(s, ALLOC_FASTPATH);
        }