mm/slab: align cache size first before determination of OFF_SLAB candidate

Finding suitable OFF_SLAB candidate is more related to aligned cache
size rather than original size.  Same reasoning can be applied to the
debug pagealloc candidate.  So, this patch moves up alignment fixup to
proper position.  From that point, size is aligned so we can remove some
alignment fixups.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.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 b3d91b048f44e427350ad17890b7df368738e9c8..d5dffc806f8214b420a6c8f9acb34a0ef5b6ce35 100644 (file)
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -2125,6 +2125,17 @@ __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags)
                else
                        size += BYTES_PER_WORD;
        }
+#endif
+
+       size = ALIGN(size, cachep->align);
+       /*
+        * We should restrict the number of objects in a slab to implement
+        * byte sized index. Refer comment on SLAB_OBJ_MIN_SIZE definition.
+        */
+       if (FREELIST_BYTE_INDEX && size < SLAB_OBJ_MIN_SIZE)
+               size = ALIGN(SLAB_OBJ_MIN_SIZE, cachep->align);
+
+#if DEBUG
        /*
         * To activate debug pagealloc, off-slab management is necessary
         * requirement. In early phase of initialization, small sized slab
@@ -2135,8 +2146,8 @@ __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags)
        if (debug_pagealloc_enabled() && (flags & SLAB_POISON) &&
                !slab_early_init && size >= kmalloc_size(INDEX_NODE) &&
                size >= 256 && cachep->object_size > cache_line_size() &&
-               ALIGN(size, cachep->align) < PAGE_SIZE) {
-               cachep->obj_offset += PAGE_SIZE - ALIGN(size, cachep->align);
+               size < PAGE_SIZE) {
+               cachep->obj_offset += PAGE_SIZE - size;
                size = PAGE_SIZE;
        }
 #endif
@@ -2148,20 +2159,13 @@ __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags)
         * SLAB_NOLEAKTRACE to avoid recursive calls into kmemleak)
         */
        if (size >= OFF_SLAB_MIN_SIZE && !slab_early_init &&
-           !(flags & SLAB_NOLEAKTRACE))
+           !(flags & SLAB_NOLEAKTRACE)) {
                /*
                 * Size is large, assume best to place the slab management obj
                 * off-slab (should allow better packing of objs).
                 */
                flags |= CFLGS_OFF_SLAB;
-
-       size = ALIGN(size, cachep->align);
-       /*
-        * We should restrict the number of objects in a slab to implement
-        * byte sized index. Refer comment on SLAB_OBJ_MIN_SIZE definition.
-        */
-       if (FREELIST_BYTE_INDEX && size < SLAB_OBJ_MIN_SIZE)
-               size = ALIGN(SLAB_OBJ_MIN_SIZE, cachep->align);
+       }
 
        left_over = calculate_slab_order(cachep, size, flags);