diff options
| author | Christoph Lameter <cl@linux.com> | 2012-11-28 16:23:16 +0000 |
|---|---|---|
| committer | Pekka Enberg <penberg@kernel.org> | 2012-12-11 12:14:28 +0200 |
| commit | 4590685546a374fb0f60682ce0e3a6fd48911d46 (patch) | |
| tree | 1287ce1e1633067f8bf2cf9f93f1d6fe8a1f8908 /mm/slab_common.c | |
| parent | 2f9baa9fcf8d0a204ca129a671d6086cc100faab (diff) | |
mm/sl[aou]b: Common alignment code
Extract the code to do object alignment from the allocators.
Do the alignment calculations in slab_common so that the
__kmem_cache_create functions of the allocators do not have
to deal with alignment.
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
Diffstat (limited to 'mm/slab_common.c')
| -rw-r--r-- | mm/slab_common.c | 32 |
1 files changed, 30 insertions, 2 deletions
diff --git a/mm/slab_common.c b/mm/slab_common.c index 497b45c25bae..a8e76d79ee65 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -73,6 +73,34 @@ static inline int kmem_cache_sanity_check(const char *name, size_t size) #endif /* + * 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. @@ -124,7 +152,7 @@ struct kmem_cache *kmem_cache_create(const char *name, size_t size, size_t align s = kmem_cache_zalloc(kmem_cache, GFP_KERNEL); if (s) { s->object_size = s->size = size; - s->align = align; + s->align = calculate_alignment(flags, align, size); s->ctor = ctor; s->name = kstrdup(name, GFP_KERNEL); if (!s->name) { @@ -211,7 +239,7 @@ void __init create_boot_cache(struct kmem_cache *s, const char *name, size_t siz s->name = name; s->size = s->object_size = size; - s->align = ARCH_KMALLOC_MINALIGN; + s->align = calculate_alignment(flags, ARCH_KMALLOC_MINALIGN, size); err = __kmem_cache_create(s, flags); if (err) |