slub: Remove node check in slab_free

We can set the page pointing in the percpu structure to
NULL to have the same effect as setting c->node to NUMA_NO_NODE.

Gets rid of one check in slab_free() that was only used for
forcing the slab_free to the slowpath for debugging.

We still need to set c->node to NUMA_NO_NODE to force the
slab_alloc() fastpath to the slowpath in case of debugging.
Signed-off-by: NChristoph Lameter <cl@linux.com>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

mm/slub.c

@@ -1881,6 +1881,8 @@ static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
 
 	page->inuse++;
 	page->freelist = get_freepointer(s, object);
+	deactivate_slab(s, c);
+	c->page = NULL;
 	c->node = NUMA_NO_NODE;
 	goto unlock_out;
 }
@@ -2112,7 +2114,7 @@ static __always_inline void slab_free(struct kmem_cache *s,
 	tid = c->tid;
 	barrier();
 
-	if (likely(page == c->page && c->node != NUMA_NO_NODE)) {
+	if (likely(page == c->page)) {
 		set_freepointer(s, object, c->freelist);
 
 		if (unlikely(!this_cpu_cmpxchg_double(