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: Do not unlock mutexes that are not taken during early boot.
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 2012-09-19 09:21:14.422971030 -0500
+++ linux/mm/slub.c 2012-09-19 09:21:18.403053765 -0500
@@ -3649,9 +3649,6 @@ static void __init kmem_cache_bootstrap_
{
int node;
- list_add(&s->list, &slab_caches);
- s->refcount = -1;
-
for_each_node_state(node, N_NORMAL_MEMORY) {
struct kmem_cache_node *n = get_node(s, node);
struct page *p;
@@ -3668,14 +3665,13 @@ static void __init kmem_cache_bootstrap_
}
}
+static __initdata struct kmem_cache boot_kmem_cache,
+ boot_kmem_cache_node;
+
void __init kmem_cache_init(void)
{
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;
@@ -3683,53 +3679,32 @@ void __init kmem_cache_init(void)
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_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(&boot_kmem_cache, "kmem_cache", kmem_size,
+ SLAB_HWCACHE_ALIGN);
- kmem_cache = kmem_cache_alloc(kmem_cache, GFP_NOWAIT);
- memcpy(kmem_cache, temp_kmem_cache, kmem_size);
+ kmem_cache = kmem_cache_alloc(&boot_kmem_cache, GFP_NOWAIT);
+ memcpy(kmem_cache, &boot_kmem_cache, kmem_size);
/*
* 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);
+ memcpy(kmem_cache_node, &boot_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);
/* Now we can use the kmem_cache to allocate kmalloc slabs */
@@ -3930,6 +3905,10 @@ int __kmem_cache_create(struct kmem_cach
if (err)
return err;
+ /* Mutex is not taken during early boot */
+ if (slab_state <= UP)
+ return 0;
+
mutex_unlock(&slab_mutex);
err = sysfs_slab_add(s);
mutex_lock(&slab_mutex);
--
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