*
* SLAB is emulated on top of SLOB by simply calling constructors and
* destructors for every SLAB allocation. Objects are returned with
- * the 8-byte alignment unless the SLAB_MUST_HWCACHE_ALIGN flag is
+ * the 8-byte alignment unless the SLAB_HWCACHE_ALIGN flag is
* set, in which case the low-level allocator will fragment blocks to
* create the proper alignment. Again, objects of page-size or greater
* are allocated by calling __get_free_pages. As SLAB objects know
#include <linux/init.h>
#include <linux/module.h>
#include <linux/timer.h>
+#include <linux/rcupdate.h>
struct slob_block {
int units;
};
typedef struct bigblock bigblock_t;
+/*
+ * struct slob_rcu is inserted at the tail of allocated slob blocks, which
+ * were created with a SLAB_DESTROY_BY_RCU slab. slob_rcu is used to free
+ * the block using call_rcu.
+ */
+struct slob_rcu {
+ struct rcu_head head;
+ int size;
+};
+
static slob_t arena = { .next = &arena, .units = 1 };
static slob_t *slobfree = &arena;
static bigblock_t *bigblocks;
static DEFINE_SPINLOCK(block_lock);
static void slob_free(void *b, int size);
+static void slob_timer_cbk(void);
+
static void *slob_alloc(size_t size, gfp_t gfp, int align)
{
spin_unlock_irqrestore(&slob_lock, flags);
}
-static int FASTCALL(find_order(int size));
-static int fastcall find_order(int size)
-{
- int order = 0;
- for ( ; size > 4096 ; size >>=1)
- order++;
- return order;
-}
-
-void *kmalloc(size_t size, gfp_t gfp)
+void *__kmalloc(size_t size, gfp_t gfp)
{
slob_t *m;
bigblock_t *bb;
if (!bb)
return 0;
- bb->order = find_order(size);
+ bb->order = get_order(size);
bb->pages = (void *)__get_free_pages(gfp, bb->order);
if (bb->pages) {
slob_free(bb, sizeof(bigblock_t));
return 0;
}
+EXPORT_SYMBOL(__kmalloc);
-EXPORT_SYMBOL(kmalloc);
+/**
+ * krealloc - reallocate memory. The contents will remain unchanged.
+ *
+ * @p: object to reallocate memory for.
+ * @new_size: how many bytes of memory are required.
+ * @flags: the type of memory to allocate.
+ *
+ * The contents of the object pointed to are preserved up to the
+ * lesser of the new and old sizes. If @p is %NULL, krealloc()
+ * behaves exactly like kmalloc(). If @size is 0 and @p is not a
+ * %NULL pointer, the object pointed to is freed.
+ */
+void *krealloc(const void *p, size_t new_size, gfp_t flags)
+{
+ void *ret;
+
+ if (unlikely(!p))
+ return kmalloc_track_caller(new_size, flags);
+
+ if (unlikely(!new_size)) {
+ kfree(p);
+ return NULL;
+ }
+
+ ret = kmalloc_track_caller(new_size, flags);
+ if (ret) {
+ memcpy(ret, p, min(new_size, ksize(p)));
+ kfree(p);
+ }
+ return ret;
+}
+EXPORT_SYMBOL(krealloc);
void kfree(const void *block)
{
EXPORT_SYMBOL(kfree);
-unsigned int ksize(const void *block)
+size_t ksize(const void *block)
{
bigblock_t *bb;
unsigned long flags;
struct kmem_cache {
unsigned int size, align;
+ unsigned long flags;
const char *name;
void (*ctor)(void *, struct kmem_cache *, unsigned long);
- void (*dtor)(void *, struct kmem_cache *, unsigned long);
};
struct kmem_cache *kmem_cache_create(const char *name, size_t size,
if (c) {
c->name = name;
c->size = size;
+ if (flags & SLAB_DESTROY_BY_RCU) {
+ /* leave room for rcu footer at the end of object */
+ c->size += sizeof(struct slob_rcu);
+ }
+ c->flags = flags;
c->ctor = ctor;
- c->dtor = dtor;
/* ignore alignment unless it's forced */
- c->align = (flags & SLAB_MUST_HWCACHE_ALIGN) ? SLOB_ALIGN : 0;
+ c->align = (flags & SLAB_HWCACHE_ALIGN) ? SLOB_ALIGN : 0;
if (c->align < align)
c->align = align;
- }
+ } else if (flags & SLAB_PANIC)
+ panic("Cannot create slab cache %s\n", name);
return c;
}
if (c->size < PAGE_SIZE)
b = slob_alloc(c->size, flags, c->align);
else
- b = (void *)__get_free_pages(flags, find_order(c->size));
+ b = (void *)__get_free_pages(flags, get_order(c->size));
if (c->ctor)
- c->ctor(b, c, SLAB_CTOR_CONSTRUCTOR);
+ c->ctor(b, c, 0);
return b;
}
}
EXPORT_SYMBOL(kmem_cache_zalloc);
-void kmem_cache_free(struct kmem_cache *c, void *b)
+static void __kmem_cache_free(void *b, int size)
{
- if (c->dtor)
- c->dtor(b, c, 0);
-
- if (c->size < PAGE_SIZE)
- slob_free(b, c->size);
+ if (size < PAGE_SIZE)
+ slob_free(b, size);
else
- free_pages((unsigned long)b, find_order(c->size));
+ free_pages((unsigned long)b, get_order(size));
+}
+
+static void kmem_rcu_free(struct rcu_head *head)
+{
+ struct slob_rcu *slob_rcu = (struct slob_rcu *)head;
+ void *b = (void *)slob_rcu - (slob_rcu->size - sizeof(struct slob_rcu));
+
+ __kmem_cache_free(b, slob_rcu->size);
+}
+
+void kmem_cache_free(struct kmem_cache *c, void *b)
+{
+ if (unlikely(c->flags & SLAB_DESTROY_BY_RCU)) {
+ struct slob_rcu *slob_rcu;
+ slob_rcu = b + (c->size - sizeof(struct slob_rcu));
+ INIT_RCU_HEAD(&slob_rcu->head);
+ slob_rcu->size = c->size;
+ call_rcu(&slob_rcu->head, kmem_rcu_free);
+ } else {
+ __kmem_cache_free(b, c->size);
+ }
}
EXPORT_SYMBOL(kmem_cache_free);
EXPORT_SYMBOL(kmem_cache_name);
static struct timer_list slob_timer = TIMER_INITIALIZER(
- (void (*)(unsigned long))kmem_cache_init, 0, 0);
+ (void (*)(unsigned long))slob_timer_cbk, 0, 0);
+
+int kmem_cache_shrink(struct kmem_cache *d)
+{
+ return 0;
+}
+EXPORT_SYMBOL(kmem_cache_shrink);
+
+int kmem_ptr_validate(struct kmem_cache *a, const void *b)
+{
+ return 0;
+}
+
+void __init kmem_cache_init(void)
+{
+ slob_timer_cbk();
+}
-void kmem_cache_init(void)
+static void slob_timer_cbk(void)
{
void *p = slob_alloc(PAGE_SIZE, 0, PAGE_SIZE-1);
git.samba.org / sfrench / cifs-2.6.git / blobdiff