slub: Dynamically size kmalloc cache allocations
kmalloc caches are statically defined and may take up a lot of space just
because the sizes of the node array has to be dimensioned for the largest
node count supported.
This patch makes the size of the kmem_cache structure dynamic throughout by
creating a kmem_cache slab cache for the kmem_cache objects. The bootstrap
occurs by allocating the initial one or two kmem_cache objects from the
page allocator.
C2->C3
- Fix various issues indicated by David
- Make create kmalloc_cache return a kmem_cache * pointer.
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h
index 9f63538..a6c43ec 100644
--- a/include/linux/slub_def.h
+++ b/include/linux/slub_def.h
@@ -139,19 +139,16 @@
#ifdef CONFIG_ZONE_DMA
#define SLUB_DMA __GFP_DMA
-/* Reserve extra caches for potential DMA use */
-#define KMALLOC_CACHES (2 * SLUB_PAGE_SHIFT)
#else
/* Disable DMA functionality */
#define SLUB_DMA (__force gfp_t)0
-#define KMALLOC_CACHES SLUB_PAGE_SHIFT
#endif
/*
* We keep the general caches in an array of slab caches that are used for
* 2^x bytes of allocations.
*/
-extern struct kmem_cache kmalloc_caches[KMALLOC_CACHES];
+extern struct kmem_cache *kmalloc_caches[SLUB_PAGE_SHIFT];
/*
* Sorry that the following has to be that ugly but some versions of GCC
@@ -216,7 +213,7 @@
if (index == 0)
return NULL;
- return &kmalloc_caches[index];
+ return kmalloc_caches[index];
}
void *kmem_cache_alloc(struct kmem_cache *, gfp_t);