mm, slub: extract get_partial() from new_slab_objects()

The later patches will need more fine grained control over individual actions
in ___slab_alloc(), the only caller of new_slab_objects(), so this is a first
preparatory step with no functional change.

This adds a goto label that appears unnecessary at this point, but will be
useful for later changes.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Christoph Lameter <cl@linux.com>

mm/slub.c

@@ -2613,17 +2613,12 @@ slab_out_of_memory(struct kmem_cache *s, gfp_t gfpflags, int nid)
 static inline void *new_slab_objects(struct kmem_cache *s, gfp_t flags,
 			int node, struct kmem_cache_cpu **pc)
 {
-	void *freelist;
+	void *freelist = NULL;
 	struct kmem_cache_cpu *c = *pc;
 	struct page *page;
 
 	WARN_ON_ONCE(s->ctor && (flags & __GFP_ZERO));
 
-	freelist = get_partial(s, flags, node, c);
-
-	if (freelist)
-		return freelist;
-
 	page = new_slab(s, flags, node);
 	if (page) {
 		c = raw_cpu_ptr(s->cpu_slab);
@@ -2787,6 +2782,10 @@ static void *___slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
 		goto redo;
 	}
 
+	freelist = get_partial(s, gfpflags, node, c);
+	if (freelist)
+		goto check_new_page;
+
 	freelist = new_slab_objects(s, gfpflags, node, &c);
 
 	if (unlikely(!freelist)) {
@@ -2794,6 +2793,7 @@ static void *___slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
 		return NULL;
 	}
 
+check_new_page:
 	page = c->page;
 	if (likely(!kmem_cache_debug(s) && pfmemalloc_match(page, gfpflags)))
 		goto load_freelist;