From: Christoph Lameter Date: Wed, 9 May 2007 09:32:35 +0000 (-0700) Subject: SLUB: add support for dynamic cacheline size determination X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=65c02d4cfbbd10188ded3d6577922ab034d943ba;p=openwrt%2Fstaging%2Fblogic.git SLUB: add support for dynamic cacheline size determination 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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/mm/slub.c b/mm/slub.c index 5db3da5a60bf..40e92d8d4bc6 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -157,6 +157,11 @@ /* Internal SLUB flags */ #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); #ifdef CONFIG_SMP @@ -1480,8 +1485,8 @@ static unsigned long calculate_alignment(unsigned long flags, * then use it. */ if ((flags & SLAB_HWCACHE_ALIGN) && - size > L1_CACHE_BYTES / 2) - return max_t(unsigned long, align, L1_CACHE_BYTES); + size > cache_line_size() / 2) + return max_t(unsigned long, align, cache_line_size()); if (align < ARCH_SLAB_MINALIGN) return ARCH_SLAB_MINALIGN; @@ -1667,8 +1672,8 @@ static int calculate_sizes(struct kmem_cache *s) size += sizeof(void *); /* * Determine the alignment based on various parameters that the - * user specified (this is unecessarily complex due to the attempt - * to be compatible with SLAB. Should be cleaned up some day). + * user specified and the dynamic determination of cache line size + * on bootup. */ 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," " 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, nr_cpu_ids, nr_node_ids); }