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.
V1->V2:
- Use kmem_cache_zalloc to properly zero structures.
- Simplify setup by introducing a new boottime
function "bootstrap()".
V2->V3:
- bootstrap function adds slab to list of slab caches
*after* performing relocation.
- Get of of kmem_size.
- Make static boot structures local to kmem_cache_init
Reviewed-by: Glauber Costa <glommer@xxxxxxxxxxxxx>
Signed-off-by: Christoph Lameter <cl@xxxxxxxxx>
---
mm/slub.c | 41 +++++++++++------------------------------
1 file changed, 11 insertions(+), 30 deletions(-)
Index: linux/mm/slub.c
===================================================================
--- linux.orig/mm/slub.c 2012-11-01 16:08:07.489743348 -0500
+++ linux/mm/slub.c 2012-11-01 16:11:31.068603160 -0500
@@ -176,8 +176,6 @@ static inline int kmem_cache_debug(struc
#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
@@ -3632,15 +3630,16 @@ static int slab_memory_callback(struct n
/*
* 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);
@@ -3656,70 +3655,44 @@ static void __init kmem_cache_bootstrap_
#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 *);
+ kmem_cache_node = &boot_kmem_cache_node;
+ kmem_cache = &boot_kmem_cache;
- /* 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->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 */
--
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