The patch titled
Subject: slub: avoid duplicate creation on the first object
has been removed from the -mm tree. Its filename was
slub-reduce-duplicate-creation-on-the-first-object.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Wei Yang <weiyang@xxxxxxxxxxxxxxxxxx>
Subject: slub: avoid duplicate creation on the first object
When a kmem_cache is created with ctor, each object in the kmem_cache will
be initialized before ready to use. While in slub implementation, the
first object will be initialized twice.
This patch reduces the duplication of initialization of the first object.
Fix commit 7656c72b ("SLUB: add macros for scanning objects in a slab").
Signed-off-by: Wei Yang <weiyang@xxxxxxxxxxxxxxxxxx>
Acked-by: Christoph Lameter <cl@xxxxxxxxx>
Cc: Pekka Enberg <penberg@xxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/slub.c | 19 +++++++++++--------
1 file changed, 11 insertions(+), 8 deletions(-)
diff -puN mm/slub.c~slub-reduce-duplicate-creation-on-the-first-object mm/slub.c
--- a/mm/slub.c~slub-reduce-duplicate-creation-on-the-first-object
+++ a/mm/slub.c
@@ -283,6 +283,10 @@ static inline void set_freepointer(struc
for (__p = (__addr); __p < (__addr) + (__objects) * (__s)->size;\
__p += (__s)->size)
+#define for_each_object_idx(__p, __idx, __s, __addr, __objects) \
+ for (__p = (__addr), __idx = 1; __idx <= __objects;\
+ __p += (__s)->size, __idx++)
+
/* Determine object index from a given position */
static inline int slab_index(void *p, struct kmem_cache *s, void *addr)
{
@@ -1379,9 +1383,9 @@ static struct page *new_slab(struct kmem
{
struct page *page;
void *start;
- void *last;
void *p;
int order;
+ int idx;
BUG_ON(flags & GFP_SLAB_BUG_MASK);
@@ -1402,14 +1406,13 @@ static struct page *new_slab(struct kmem
if (unlikely(s->flags & SLAB_POISON))
memset(start, POISON_INUSE, PAGE_SIZE << order);
- last = start;
- for_each_object(p, s, start, page->objects) {
- setup_object(s, page, last);
- set_freepointer(s, last, p);
- last = p;
+ for_each_object_idx(p, idx, s, start, page->objects) {
+ setup_object(s, page, p);
+ if (likely(idx < page->objects))
+ set_freepointer(s, p, p + s->size);
+ else
+ set_freepointer(s, p, NULL);
}
- setup_object(s, page, last);
- set_freepointer(s, last, NULL);
page->freelist = start;
page->inuse = page->objects;
_
Patches currently in -mm which might be from weiyang@xxxxxxxxxxxxxxxxxx are
origin.patch
rbtree-fix-typo-in-comment-of-__rb_insert.patch
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