From mboxrd@z Thu Jan 1 00:00:00 1970 Message-Id: <20070614075336.870895145@sgi.com> References: <20070614075026.607300756@sgi.com> Date: Thu, 14 Jun 2007 00:50:38 -0700 From: clameter@sgi.com Subject: [RFC 12/13] SLUB: minimum alignment fixes Content-Disposition: inline; filename=slub_min_align Sender: owner-linux-mm@kvack.org Return-Path: To: Nishanth Aravamudan Cc: Lee Schermerhorn , linux-mm@kvack.org List-ID: If ARCH_KMALLOC_MINALIGN is set to a value greater than 8 (SLUBs smallest kmalloc cache) then SLUB may generate duplicate slabs in sysfs (yes again). However, no arch sets ARCH_KMALLOC_MINALIGN larger than 8 though except mips which for some reason wants a 128 byte alignment. This patch increases the size of the smallest cache if ARCH_KMALLOC_MINALIGN is greater than 8. In that case more and more of the smallest caches are disabled. If we do that then the count of the active general caches that is displayed on boot is not correct anymore since we may skip elements of the kmalloc array. So count them separately. Signed-off-by: Christoph Lameter --- include/linux/slub_def.h | 13 +++++++++++-- mm/slub.c | 20 +++++++++++++++----- 2 files changed, 26 insertions(+), 7 deletions(-) Index: vps/include/linux/slub_def.h =================================================================== --- vps.orig/include/linux/slub_def.h 2007-06-12 15:58:30.000000000 -0700 +++ vps/include/linux/slub_def.h 2007-06-12 16:00:43.000000000 -0700 @@ -28,7 +28,7 @@ struct kmem_cache { int size; /* The size of an object including meta data */ int objsize; /* The size of an object without meta data */ int offset; /* Free pointer offset. */ - unsigned int order; + int order; /* * Avoid an extra cache line for UP, SMP and for the node local to @@ -56,7 +56,13 @@ struct kmem_cache { /* * Kmalloc subsystem. */ -#define KMALLOC_SHIFT_LOW 3 +#if defined(ARCH_KMALLOC_MINALIGN) && ARCH_KMALLOC_MINALIGN > 8 +#define KMALLOC_MIN_SIZE ARCH_KMALLOC_MINALIGN +#else +#define KMALLOC_MIN_SIZE 8 +#endif + +#define KMALLOC_SHIFT_LOW ilog2(KMALLOC_MIN_SIZE) /* * We keep the general caches in an array of slab caches that are used for @@ -76,6 +82,9 @@ static inline int kmalloc_index(size_t s if (size > KMALLOC_MAX_SIZE) return -1; + if (size <= KMALLOC_MIN_SIZE) + return KMALLOC_SHIFT_LOW; + if (size > 64 && size <= 96) return 1; if (size > 128 && size <= 192) Index: vps/mm/slub.c =================================================================== --- vps.orig/mm/slub.c 2007-06-12 15:58:37.000000000 -0700 +++ vps/mm/slub.c 2007-06-12 16:03:00.000000000 -0700 @@ -2521,6 +2521,7 @@ EXPORT_SYMBOL(krealloc); void __init kmem_cache_init(void) { int i; + int caches = 0; if (!page_group_by_mobility_disabled && !user_override) { /* @@ -2540,20 +2541,29 @@ void __init kmem_cache_init(void) create_kmalloc_cache(&kmalloc_caches[0], "kmem_cache_node", sizeof(struct kmem_cache_node), GFP_KERNEL); kmalloc_caches[0].refcount = -1; + caches++; #endif /* Able to allocate the per node structures */ slab_state = PARTIAL; /* Caches that are not of the two-to-the-power-of size */ - create_kmalloc_cache(&kmalloc_caches[1], + if (KMALLOC_MIN_SIZE <= 64) { + create_kmalloc_cache(&kmalloc_caches[1], "kmalloc-96", 96, GFP_KERNEL); - create_kmalloc_cache(&kmalloc_caches[2], + caches++; + } + if (KMALLOC_MIN_SIZE <= 128) { + create_kmalloc_cache(&kmalloc_caches[2], "kmalloc-192", 192, GFP_KERNEL); + caches++; + } - for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++) + for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++) { create_kmalloc_cache(&kmalloc_caches[i], "kmalloc", 1 << i, GFP_KERNEL); + caches++; + } slab_state = UP; @@ -2570,8 +2580,8 @@ void __init kmem_cache_init(void) nr_cpu_ids * sizeof(struct page *); printk(KERN_INFO "SLUB: Genslabs=%d, HWalign=%d, Order=%d-%d, MinObjects=%d," - " Processors=%d, Nodes=%d\n", - KMALLOC_SHIFT_HIGH, cache_line_size(), + " CPUs=%d, Nodes=%d\n", + caches, cache_line_size(), slub_min_order, slub_max_order, slub_min_objects, nr_cpu_ids, nr_node_ids); } -- -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org