mm/slab.c: add a helper function get_first_slab

Add a new helper function get_first_slab() that get the first slab from
a kmem_cache_node.

Signed-off-by: Geliang Tang <geliangtang@163.com>
Acked-by: Christoph Lameter <cl@linux.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/slab.c b/mm/slab.c
index 5d5aa3b..6ecc697 100644 (file)
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -2756,6 +2756,21 @@ static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp,
 #define cache_free_debugcheck(x,objp,z) (objp)
 #endif
 
+static struct page *get_first_slab(struct kmem_cache_node *n)
+{
+       struct page *page;
+
+       page = list_first_entry_or_null(&n->slabs_partial,
+                       struct page, lru);
+       if (!page) {
+               n->free_touched = 1;
+               page = list_first_entry_or_null(&n->slabs_free,
+                               struct page, lru);
+       }
+
+       return page;
+}
+
 static void *cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags,
                                                        bool force_refill)
 {
@@ -2793,15 +2808,9 @@ retry:
        while (batchcount > 0) {
                struct page *page;
                /* Get slab alloc is to come from. */
-               page = list_first_entry_or_null(&n->slabs_partial,
-                               struct page, lru);
-               if (!page) {
-                       n->free_touched = 1;
-                       page = list_first_entry_or_null(&n->slabs_free,
-                                       struct page, lru);
-                       if (!page)
-                               goto must_grow;
-               }
+               page = get_first_slab(n);
+               if (!page)
+                       goto must_grow;
 
                check_spinlock_acquired(cachep);
 
@@ -3097,15 +3106,9 @@ static void *____cache_alloc_node(struct kmem_cache *cachep, gfp_t flags,
 retry:
        check_irq_off();
        spin_lock(&n->list_lock);
-       page = list_first_entry_or_null(&n->slabs_partial,
-                       struct page, lru);
-       if (!page) {
-               n->free_touched = 1;
-               page = list_first_entry_or_null(&n->slabs_free,
-                               struct page, lru);
-               if (!page)
-                       goto must_grow;
-       }
+       page = get_first_slab(n);
+       if (!page)
+               goto must_grow;
 
        check_spinlock_acquired_node(cachep, nodeid);