Extract the code to do object alignment from the allocators.
Signed-off-by: Christoph Lameter <cl@xxxxxxxxx>
---
mm/slab.c | 22 +---------------------
mm/slab.h | 3 +++
mm/slab_common.c | 30 +++++++++++++++++++++++++++++-
mm/slob.c | 13 +------------
mm/slub.c | 47 +++++++++--------------------------------------
5 files changed, 43 insertions(+), 72 deletions(-)
Index: linux-2.6/mm/slab.c
===================================================================
--- linux-2.6.orig/mm/slab.c 2012-05-23 08:12:53.750739568 -0500
+++ linux-2.6/mm/slab.c 2012-05-23 08:37:31.602708946 -0500
@@ -1445,7 +1445,7 @@ struct kmem_cache *create_kmalloc_cache(
s->name = name;
s->size = size;
- s->align = ARCH_KMALLOC_MINALIGN;
+ s->align = calculate_alignment(flags, ARCH_KMALLOC_MINALIGN, size);
s->flags = flags | ARCH_KMALLOC_FLAGS;
r = __kmem_cache_create(s);
@@ -2249,22 +2249,6 @@ int __kmem_cache_create(struct kmem_cach
size &= ~(BYTES_PER_WORD - 1);
}
- /* calculate the final buffer alignment: */
-
- /* 1) arch recommendation: can be overridden for debug */
- if (flags & SLAB_HWCACHE_ALIGN) {
- /*
- * Default alignment: as specified by the arch code. Except if
- * an object is really small, then squeeze multiple objects into
- * one cacheline.
- */
- ralign = cache_line_size();
- while (size <= ralign / 2)
- ralign /= 2;
- } else {
- ralign = BYTES_PER_WORD;
- }
-
/*
* Redzoning and user store require word alignment or possibly larger.
* Note this will be overridden by architecture or caller mandated
@@ -2281,10 +2265,6 @@ int __kmem_cache_create(struct kmem_cach
size &= ~(REDZONE_ALIGN - 1);
}
- /* 2) arch mandated alignment */
- if (ralign < ARCH_SLAB_MINALIGN) {
- ralign = ARCH_SLAB_MINALIGN;
- }
/* 3) caller mandated alignment */
if (ralign < cachep->align) {
ralign = cachep->align;
Index: linux-2.6/mm/slab_common.c
===================================================================
--- linux-2.6.orig/mm/slab_common.c 2012-05-23 08:12:53.810739566 -0500
+++ linux-2.6/mm/slab_common.c 2012-05-23 08:20:10.614730515 -0500
@@ -25,6 +25,34 @@ DEFINE_MUTEX(slab_mutex);
struct kmem_cache *kmem_cache;
/*
+ * Figure out what the alignment of the objects will be given a set of
+ * flags, a user specified alignment and the size of the objects.
+ */
+unsigned long calculate_alignment(unsigned long flags,
+ unsigned long align, unsigned long size)
+{
+ /*
+ * If the user wants hardware cache aligned objects then follow that
+ * suggestion if the object is sufficiently large.
+ *
+ * The hardware cache alignment cannot override the specified
+ * alignment though. If that is greater then use it.
+ */
+ if (flags & SLAB_HWCACHE_ALIGN) {
+ unsigned long ralign = cache_line_size();
+ while (size <= ralign / 2)
+ ralign /= 2;
+ align = max(align, ralign);
+ }
+
+ if (align < ARCH_SLAB_MINALIGN)
+ align = ARCH_SLAB_MINALIGN;
+
+ return ALIGN(align, sizeof(void *));
+}
+
+
+/*
* kmem_cache_create - Create a cache.
* @name: A string which is used in /proc/slabinfo to identify this cache.
* @size: The size of objects to be created in this cache.
@@ -117,7 +145,7 @@ struct kmem_cache *kmem_cache_create(con
s->name = n;
s->ctor = ctor;
s->size = size;
- s->align = align;
+ s->align = calculate_alignment(flags, align, size);
s->flags = flags;
r = __kmem_cache_create(s);
Index: linux-2.6/mm/slob.c
===================================================================
--- linux-2.6.orig/mm/slob.c 2012-05-23 08:12:53.734739565 -0500
+++ linux-2.6/mm/slob.c 2012-05-23 08:13:42.226738561 -0500
@@ -124,7 +124,6 @@ static inline void clear_slob_page_free(
#define SLOB_UNIT sizeof(slob_t)
#define SLOB_UNITS(size) (((size) + SLOB_UNIT - 1)/SLOB_UNIT)
-#define SLOB_ALIGN L1_CACHE_BYTES
/*
* struct slob_rcu is inserted at the tail of allocated slob blocks, which
@@ -510,21 +509,11 @@ EXPORT_SYMBOL(ksize);
int __kmem_cache_create(struct kmem_cache *c)
{
- int flags = c->flags;
- int align = c->align;
-
- if (flags & SLAB_DESTROY_BY_RCU) {
+ if (c->flags & SLAB_DESTROY_BY_RCU) {
/* leave room for rcu footer at the end of object */
c->size += sizeof(struct slob_rcu);
}
- /* ignore alignment unless it's forced */
- c->align = (flags & SLAB_HWCACHE_ALIGN) ? SLOB_ALIGN : 0;
- if (c->align < ARCH_SLAB_MINALIGN)
- c->align = ARCH_SLAB_MINALIGN;
- if (c->align < align)
- c->align = align;
- kmemleak_alloc(c, sizeof(struct kmem_cache), 1, GFP_KERNEL);
return 0;
}
Index: linux-2.6/mm/slub.c
===================================================================
--- linux-2.6.orig/mm/slub.c 2012-05-23 08:12:53.774739565 -0500
+++ linux-2.6/mm/slub.c 2012-05-23 08:35:32.002711423 -0500
@@ -2724,32 +2724,6 @@ static inline int calculate_order(int si
return -ENOSYS;
}
-/*
- * Figure out what the alignment of the objects will be.
- */
-static unsigned long calculate_alignment(unsigned long flags,
- unsigned long align, unsigned long size)
-{
- /*
- * If the user wants hardware cache aligned objects then follow that
- * suggestion if the object is sufficiently large.
- *
- * The hardware cache alignment cannot override the specified
- * alignment though. If that is greater then use it.
- */
- if (flags & SLAB_HWCACHE_ALIGN) {
- unsigned long ralign = cache_line_size();
- while (size <= ralign / 2)
- ralign /= 2;
- align = max(align, ralign);
- }
-
- if (align < ARCH_SLAB_MINALIGN)
- align = ARCH_SLAB_MINALIGN;
-
- return ALIGN(align, sizeof(void *));
-}
-
static void
init_kmem_cache_node(struct kmem_cache_node *n, struct kmem_cache *s)
{
@@ -2882,7 +2856,7 @@ static void set_min_partial(struct kmem_
static int calculate_sizes(struct kmem_cache *s, int forced_order)
{
unsigned long flags = s->flags;
- unsigned long size = s->objsize;
+ unsigned long size = s->size;
unsigned long align = s->align;
int order;
@@ -2955,14 +2929,6 @@ static int calculate_sizes(struct kmem_c
#endif
/*
- * Determine the alignment based on various parameters that the
- * user specified and the dynamic determination of cache line size
- * on bootup.
- */
- align = calculate_alignment(flags, align, s->objsize);
- s->align = align;
-
- /*
* SLUB stores one object immediately after another beginning from
* offset 0. In order to align the objects we have to simply size
* each object to conform to the alignment.
@@ -2996,7 +2962,6 @@ static int calculate_sizes(struct kmem_c
s->max = s->oo;
return !!oo_objects(s->oo);
-
}
static int kmem_cache_open(struct kmem_cache *s)
@@ -3221,7 +3186,7 @@ static struct kmem_cache *__init create_
s = kmem_cache_zalloc(kmem_cache, GFP_NOWAIT);
s->name = name;
s->size = size;
- s->align = ARCH_KMALLOC_MINALIGN;
+ s->align = calculate_alignment(flags, ARCH_KMALLOC_MINALIGN, size);
s->flags = flags;
/*
@@ -3682,6 +3647,8 @@ void __init kmem_cache_init(void)
kmem_cache_node->name = "kmem_cache_node";
kmem_cache_node->size = sizeof(struct kmem_cache_node);
kmem_cache_node->flags = SLAB_HWCACHE_ALIGN;
+ kmem_cache_node->align = calculate_alignment(SLAB_HWCACHE_ALIGN,
+ 0, sizeof(struct kmem_cache_node));
r = kmem_cache_open(kmem_cache_node);
if (r)
@@ -3696,6 +3663,8 @@ void __init kmem_cache_init(void)
kmem_cache->name = "kmem_cache";
kmem_cache->size = kmem_size;
kmem_cache->flags = SLAB_HWCACHE_ALIGN;
+ kmem_cache->align = calculate_alignment(SLAB_HWCACHE_ALIGN,
+ 0, sizeof(struct kmem_cache));
r = kmem_cache_open(kmem_cache);
if (r)
@@ -3919,7 +3888,9 @@ struct kmem_cache *__kmem_cache_alias(co
int __kmem_cache_create(struct kmem_cache *s)
{
- int r = kmem_cache_open(s);
+ int r;
+
+ r = kmem_cache_open(s);
if (r)
return r;
Index: linux-2.6/mm/slab.h
===================================================================
--- linux-2.6.orig/mm/slab.h 2012-05-23 08:12:53.790739566 -0500
+++ linux-2.6/mm/slab.h 2012-05-23 08:13:42.226738561 -0500
@@ -32,6 +32,9 @@ extern struct list_head slab_caches;
/* The slab cache that manages slab cache information */
extern struct kmem_cache *kmem_cache;
+unsigned long calculate_alignment(unsigned long flags,
+ unsigned long align, unsigned long size);
+
/* Functions provided by the slab allocators */
int __kmem_cache_create(struct kmem_cache *s);
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>