SLUB: add support for kmem_cache_ops We use the parameter formerly used by the destructor to pass an optional pointer to a kmem_cache_ops structure to kmem_cache_create. kmem_cache_ops is created as empty. Later patches populate kmem_cache_ops. Create a KMEM_CACHE_OPS macro that allows the specification of a the kmem_cache_ops. Code to handle kmem_cache_ops is added to SLUB. SLAB and SLOB are updated to be able to accept a kmem_cache_ops structure but will ignore it. Signed-off-by: Christoph Lameter --- include/linux/slab.h | 13 +++++++++---- include/linux/slub_def.h | 1 + mm/slab.c | 6 +++--- mm/slob.c | 2 +- mm/slub.c | 44 ++++++++++++++++++++++++++++++-------------- 5 files changed, 44 insertions(+), 22 deletions(-) Index: linux-2.6.22-rc4-mm2/include/linux/slab.h =================================================================== --- linux-2.6.22-rc4-mm2.orig/include/linux/slab.h 2007-06-15 17:35:33.000000000 -0700 +++ linux-2.6.22-rc4-mm2/include/linux/slab.h 2007-06-16 15:39:35.000000000 -0700 @@ -38,10 +38,13 @@ void __init kmem_cache_init(void); int slab_is_available(void); +struct kmem_cache_ops { +}; + struct kmem_cache *kmem_cache_create(const char *, size_t, size_t, unsigned long, void (*)(void *, struct kmem_cache *, unsigned long), - void (*)(void *, struct kmem_cache *, unsigned long)); + const struct kmem_cache_ops *s); void kmem_cache_destroy(struct kmem_cache *); int kmem_cache_shrink(struct kmem_cache *); void *kmem_cache_alloc(struct kmem_cache *, gfp_t); @@ -59,9 +62,11 @@ int kmem_ptr_validate(struct kmem_cache * f.e. add ____cacheline_aligned_in_smp to the struct declaration * then the objects will be properly aligned in SMP configurations. */ -#define KMEM_CACHE(__struct, __flags) kmem_cache_create(#__struct,\ - sizeof(struct __struct), __alignof__(struct __struct),\ - (__flags), NULL, NULL) +#define KMEM_CACHE_OPS(__struct, __flags, __ops) \ + kmem_cache_create(#__struct, sizeof(struct __struct), \ + __alignof__(struct __struct), (__flags), NULL, (__ops)) + +#define KMEM_CACHE(__struct, __flags) KMEM_CACHE_OPS(__struct, __flags, NULL) #ifdef CONFIG_NUMA extern void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node); Index: linux-2.6.22-rc4-mm2/mm/slub.c =================================================================== --- linux-2.6.22-rc4-mm2.orig/mm/slub.c 2007-06-16 15:38:09.000000000 -0700 +++ linux-2.6.22-rc4-mm2/mm/slub.c 2007-06-16 15:39:35.000000000 -0700 @@ -299,6 +299,9 @@ static inline int check_valid_pointer(st return 1; } +struct kmem_cache_ops slub_default_ops = { +}; + /* * Slow version of get and set free pointer. * @@ -2074,11 +2077,13 @@ static int calculate_sizes(struct kmem_c static int kmem_cache_open(struct kmem_cache *s, gfp_t gfpflags, const char *name, size_t size, size_t align, unsigned long flags, - void (*ctor)(void *, struct kmem_cache *, unsigned long)) + void (*ctor)(void *, struct kmem_cache *, unsigned long), + const struct kmem_cache_ops *ops) { memset(s, 0, kmem_size); s->name = name; s->ctor = ctor; + s->ops = ops; s->objsize = size; s->flags = flags; s->align = align; @@ -2261,7 +2266,7 @@ static struct kmem_cache *create_kmalloc down_write(&slub_lock); if (!kmem_cache_open(s, gfp_flags, name, size, ARCH_KMALLOC_MINALIGN, - flags, NULL)) + flags, NULL, &slub_default_ops)) goto panic; list_add(&s->list, &slab_caches); @@ -2602,12 +2607,16 @@ static int slab_unmergeable(struct kmem_ if (s->refcount < 0) return 1; + if (s->ops != &slub_default_ops) + return 1; + return 0; } static struct kmem_cache *find_mergeable(size_t size, size_t align, unsigned long flags, - void (*ctor)(void *, struct kmem_cache *, unsigned long)) + void (*ctor)(void *, struct kmem_cache *, unsigned long), + const struct kmem_cache_ops *ops) { struct kmem_cache *s; @@ -2617,6 +2626,9 @@ static struct kmem_cache *find_mergeable if (ctor) return NULL; + if (ops != &slub_default_ops) + return NULL; + size = ALIGN(size, sizeof(void *)); align = calculate_alignment(flags, align, size); size = ALIGN(size, align); @@ -2649,13 +2661,15 @@ static struct kmem_cache *find_mergeable struct kmem_cache *kmem_cache_create(const char *name, size_t size, size_t align, unsigned long flags, void (*ctor)(void *, struct kmem_cache *, unsigned long), - void (*dtor)(void *, struct kmem_cache *, unsigned long)) + const struct kmem_cache_ops *ops) { struct kmem_cache *s; - BUG_ON(dtor); + if (!ops) + ops = &slub_default_ops; + down_write(&slub_lock); - s = find_mergeable(size, align, flags, ctor); + s = find_mergeable(size, align, flags, ctor, ops); if (s) { s->refcount++; /* @@ -2669,7 +2683,7 @@ struct kmem_cache *kmem_cache_create(con } else { s = kmalloc(kmem_size, GFP_KERNEL); if (s && kmem_cache_open(s, GFP_KERNEL, name, - size, align, flags, ctor)) { + size, align, flags, ctor, ops)) { if (sysfs_slab_add(s)) { kfree(s); goto err; @@ -3291,16 +3305,18 @@ static ssize_t order_show(struct kmem_ca } SLAB_ATTR_RO(order); -static ssize_t ctor_show(struct kmem_cache *s, char *buf) +static ssize_t ops_show(struct kmem_cache *s, char *buf) { - if (s->ctor) { - int n = sprint_symbol(buf, (unsigned long)s->ctor); + int x = 0; - return n + sprintf(buf + n, "\n"); + if (s->ctor) { + x += sprintf(buf + x, "ctor : "); + x += sprint_symbol(buf + x, (unsigned long)s->ctor); + x += sprintf(buf + x, "\n"); } - return 0; + return x; } -SLAB_ATTR_RO(ctor); +SLAB_ATTR_RO(ops); static ssize_t aliases_show(struct kmem_cache *s, char *buf) { @@ -3532,7 +3548,7 @@ static struct attribute * slab_attrs[] = &slabs_attr.attr, &partial_attr.attr, &cpu_slabs_attr.attr, - &ctor_attr.attr, + &ops_attr.attr, &aliases_attr.attr, &align_attr.attr, &sanity_checks_attr.attr, Index: linux-2.6.22-rc4-mm2/include/linux/slub_def.h =================================================================== --- linux-2.6.22-rc4-mm2.orig/include/linux/slub_def.h 2007-06-16 15:38:09.000000000 -0700 +++ linux-2.6.22-rc4-mm2/include/linux/slub_def.h 2007-06-16 15:39:35.000000000 -0700 @@ -40,6 +40,7 @@ struct kmem_cache { int objects; /* Number of objects in slab */ int refcount; /* Refcount for slab cache destroy */ void (*ctor)(void *, struct kmem_cache *, unsigned long); + const struct kmem_cache_ops *ops; int inuse; /* Offset to metadata */ int align; /* Alignment */ const char *name; /* Name (only for display!) */ Index: linux-2.6.22-rc4-mm2/mm/slab.c =================================================================== --- linux-2.6.22-rc4-mm2.orig/mm/slab.c 2007-06-16 15:38:13.000000000 -0700 +++ linux-2.6.22-rc4-mm2/mm/slab.c 2007-06-16 15:39:35.000000000 -0700 @@ -2099,7 +2099,7 @@ static int __init_refok setup_cpu_cache( * @align: The required alignment for the objects. * @flags: SLAB flags * @ctor: A constructor for the objects. - * @dtor: A destructor for the objects (not implemented anymore). + * @ops: A kmem_cache_ops structure (ignored). * * Returns a ptr to the cache on success, NULL on failure. * Cannot be called within a int, but can be interrupted. @@ -2125,7 +2125,7 @@ struct kmem_cache * kmem_cache_create (const char *name, size_t size, size_t align, unsigned long flags, void (*ctor)(void*, struct kmem_cache *, unsigned long), - void (*dtor)(void*, struct kmem_cache *, unsigned long)) + const struct kmem_cache_ops *ops) { size_t left_over, slab_size, ralign; struct kmem_cache *cachep = NULL, *pc; @@ -2134,7 +2134,7 @@ kmem_cache_create (const char *name, siz * Sanity checks... these are all serious usage bugs. */ if (!name || in_interrupt() || (size < BYTES_PER_WORD) || - size > KMALLOC_MAX_SIZE || dtor) { + size > KMALLOC_MAX_SIZE) { printk(KERN_ERR "%s: Early error in slab %s\n", __FUNCTION__, name); BUG(); Index: linux-2.6.22-rc4-mm2/mm/slob.c =================================================================== --- linux-2.6.22-rc4-mm2.orig/mm/slob.c 2007-06-15 17:35:33.000000000 -0700 +++ linux-2.6.22-rc4-mm2/mm/slob.c 2007-06-16 15:39:35.000000000 -0700 @@ -483,7 +483,7 @@ struct kmem_cache { struct kmem_cache *kmem_cache_create(const char *name, size_t size, size_t align, unsigned long flags, void (*ctor)(void*, struct kmem_cache *, unsigned long), - void (*dtor)(void*, struct kmem_cache *, unsigned long)) + const struct kmem_cache_ops *o) { struct kmem_cache *c;