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SLUB: add support for dynamic cacheline size determination

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SLUB currently assumes that the cacheline size is static.  However, i386 f.e.
supports dynamic cache line size determination.

Use cache_line_size() instead of L1_CACHE_BYTES in the allocator.

That also explains the purpose of SLAB_HWCACHE_ALIGN.  So we will need to keep
that one around to allow dynamic aligning of objects depending on boot
determination of the cache line size.

[akpm@linux-foundation.org: need to define it before we use it]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Christoph Lameter
2007-05-09 02:32:35 -07:00
committed by Linus Torvalds
parent 97416ce82e
commit 65c02d4cfb
1 changed files with 10 additions and 5 deletions
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15
mm/slub.c
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@@ -157,6 +157,11 @@
/* Internal SLUB flags */ /* Internal SLUB flags */
#define __OBJECT_POISON 0x80000000 /* Poison object */ #define __OBJECT_POISON 0x80000000 /* Poison object */
/* Not all arches define cache_line_size */
#ifndef cache_line_size
#define cache_line_size() L1_CACHE_BYTES
#endif
static int kmem_size = sizeof(struct kmem_cache); static int kmem_size = sizeof(struct kmem_cache);
#ifdef CONFIG_SMP #ifdef CONFIG_SMP
@@ -1480,8 +1485,8 @@ static unsigned long calculate_alignment(unsigned long flags,
* then use it. * then use it.
*/ */
if ((flags & SLAB_HWCACHE_ALIGN) && if ((flags & SLAB_HWCACHE_ALIGN) &&
size > L1_CACHE_BYTES / 2) size > cache_line_size() / 2)
return max_t(unsigned long, align, L1_CACHE_BYTES); return max_t(unsigned long, align, cache_line_size());
if (align < ARCH_SLAB_MINALIGN) if (align < ARCH_SLAB_MINALIGN)
return ARCH_SLAB_MINALIGN; return ARCH_SLAB_MINALIGN;
@@ -1667,8 +1672,8 @@ static int calculate_sizes(struct kmem_cache *s)
size += sizeof(void *); size += sizeof(void *);
/* /*
* Determine the alignment based on various parameters that the * Determine the alignment based on various parameters that the
* user specified (this is unecessarily complex due to the attempt * user specified and the dynamic determination of cache line size
* to be compatible with SLAB. Should be cleaned up some day). * on bootup.
*/ */
align = calculate_alignment(flags, align, s->objsize); align = calculate_alignment(flags, align, s->objsize);
@@ -2280,7 +2285,7 @@ void __init kmem_cache_init(void)
printk(KERN_INFO "SLUB: Genslabs=%d, HWalign=%d, Order=%d-%d, MinObjects=%d," printk(KERN_INFO "SLUB: Genslabs=%d, HWalign=%d, Order=%d-%d, MinObjects=%d,"
" Processors=%d, Nodes=%d\n", " Processors=%d, Nodes=%d\n",
KMALLOC_SHIFT_HIGH, L1_CACHE_BYTES, KMALLOC_SHIFT_HIGH, cache_line_size(),
slub_min_order, slub_max_order, slub_min_objects, slub_min_order, slub_max_order, slub_min_objects,
nr_cpu_ids, nr_node_ids); nr_cpu_ids, nr_node_ids);
} }