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Commit dffb4d60 authored by Christoph Lameter's avatar Christoph Lameter Committed by Pekka Enberg
Browse files

slub: Use statically allocated kmem_cache boot structure for bootstrap 



Simplify bootstrap by statically allocated two kmem_cache structures. These are
freed after bootup is complete. Allows us to no longer worry about calculations
of sizes of kmem_cache structures during bootstrap.

Reviewed-by: default avatarGlauber Costa <glommer@parallels.com>
Signed-off-by: default avatarChristoph Lameter <cl@linux.com>
Signed-off-by: default avatarPekka Enberg <penberg@kernel.org>
parent 45530c44

mm/slub.c

+20 −47
Original line number Diff line number Diff line
@@ -176,8 +176,6 @@ static inline int kmem_cache_debug(struct kmem_cache *s) 
#define __OBJECT_POISON		0x80000000UL /* Poison object */

#define __CMPXCHG_DOUBLE	0x40000000UL /* Use cmpxchg_double */



static int kmem_size = sizeof(struct kmem_cache);



#ifdef CONFIG_SMP

static struct notifier_block slab_notifier;

#endif
@@ -3634,15 +3632,16 @@ static int slab_memory_callback(struct notifier_block *self, 


/*

 * Used for early kmem_cache structures that were allocated using

 * the page allocator

 * the page allocator. Allocate them properly then fix up the pointers

 * that may be pointing to the wrong kmem_cache structure.

 */



static void __init kmem_cache_bootstrap_fixup(struct kmem_cache *s)

static struct kmem_cache * __init bootstrap(struct kmem_cache *static_cache)

{

	int node;

	struct kmem_cache *s = kmem_cache_zalloc(kmem_cache, GFP_NOWAIT);



	list_add(&s->list, &slab_caches);

	s->refcount = -1;

	memcpy(s, static_cache, kmem_cache->object_size);



	for_each_node_state(node, N_NORMAL_MEMORY) {

		struct kmem_cache_node *n = get_node(s, node);
@@ -3658,70 +3657,44 @@ static void __init kmem_cache_bootstrap_fixup(struct kmem_cache *s) 
#endif

		}

	}

	list_add(&s->list, &slab_caches);

	return s;

}



void __init kmem_cache_init(void)

{

	static __initdata struct kmem_cache boot_kmem_cache,

		boot_kmem_cache_node;

	int i;

	int caches = 0;

	struct kmem_cache *temp_kmem_cache;

	int order;

	struct kmem_cache *temp_kmem_cache_node;

	unsigned long kmalloc_size;

	int caches = 2;



	if (debug_guardpage_minorder())

		slub_max_order = 0;



	kmem_size = offsetof(struct kmem_cache, node) +

			nr_node_ids * sizeof(struct kmem_cache_node *);



	/* Allocate two kmem_caches from the page allocator */

	kmalloc_size = ALIGN(kmem_size, cache_line_size());

	order = get_order(2 * kmalloc_size);

	kmem_cache = (void *)__get_free_pages(GFP_NOWAIT | __GFP_ZERO, order);



	/*

	 * Must first have the slab cache available for the allocations of the

	 * struct kmem_cache_node's. There is special bootstrap code in

	 * kmem_cache_open for slab_state == DOWN.

	 */

	kmem_cache_node = (void *)kmem_cache + kmalloc_size;

	kmem_cache_node = &boot_kmem_cache_node;

	kmem_cache = &boot_kmem_cache;



	kmem_cache_node->name = "kmem_cache_node";

	kmem_cache_node->size = kmem_cache_node->object_size =

		sizeof(struct kmem_cache_node);

	kmem_cache_open(kmem_cache_node, SLAB_HWCACHE_ALIGN | SLAB_PANIC);

	create_boot_cache(kmem_cache_node, "kmem_cache_node",

		sizeof(struct kmem_cache_node), SLAB_HWCACHE_ALIGN);



	hotplug_memory_notifier(slab_memory_callback, SLAB_CALLBACK_PRI);



	/* Able to allocate the per node structures */

	slab_state = PARTIAL;



	temp_kmem_cache = kmem_cache;

	kmem_cache->name = "kmem_cache";

	kmem_cache->size = kmem_cache->object_size = kmem_size;

	kmem_cache_open(kmem_cache, SLAB_HWCACHE_ALIGN | SLAB_PANIC);

	create_boot_cache(kmem_cache, "kmem_cache",

			offsetof(struct kmem_cache, node) +

				nr_node_ids * sizeof(struct kmem_cache_node *),

		       SLAB_HWCACHE_ALIGN);



	kmem_cache = kmem_cache_alloc(kmem_cache, GFP_NOWAIT);

	memcpy(kmem_cache, temp_kmem_cache, kmem_size);

	kmem_cache = bootstrap(&boot_kmem_cache);



	/*

	 * Allocate kmem_cache_node properly from the kmem_cache slab.

	 * kmem_cache_node is separately allocated so no need to

	 * update any list pointers.

	 */

	temp_kmem_cache_node = kmem_cache_node;



	kmem_cache_node = kmem_cache_alloc(kmem_cache, GFP_NOWAIT);

	memcpy(kmem_cache_node, temp_kmem_cache_node, kmem_size);



	kmem_cache_bootstrap_fixup(kmem_cache_node);



	caches++;

	kmem_cache_bootstrap_fixup(kmem_cache);

	caches++;

	/* Free temporary boot structure */

	free_pages((unsigned long)temp_kmem_cache, order);

	kmem_cache_node = bootstrap(&boot_kmem_cache_node);



	/* Now we can use the kmem_cache to allocate kmalloc slabs */