Merge branch 'for-ingo' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6 into tracing/kmemtrace

Conflicts:
	mm/slub.c

1 files changed, 16 insertions, 3 deletions

diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h
index 6b657f7dcb2b..9e3a575b2c30 100644
--- a/include/linux/slub_def.h
+++ b/include/linux/slub_def.h
@@ -122,10 +122,23 @@ struct kmem_cache {
 #define KMALLOC_SHIFT_LOW ilog2(KMALLOC_MIN_SIZE)
 
 /*
+ * Maximum kmalloc object size handled by SLUB. Larger object allocations
+ * are passed through to the page allocator. The page allocator "fastpath"
+ * is relatively slow so we need this value sufficiently high so that
+ * performance critical objects are allocated through the SLUB fastpath.
+ *
+ * This should be dropped to PAGE_SIZE / 2 once the page allocator
+ * "fastpath" becomes competitive with the slab allocator fastpaths.
+ */
+#define SLUB_MAX_SIZE (PAGE_SIZE)
+
+#define SLUB_PAGE_SHIFT (PAGE_SHIFT + 1)
+
+/*
  * 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[PAGE_SHIFT + 1];
+extern struct kmem_cache kmalloc_caches[SLUB_PAGE_SHIFT];
 
 /*
  * Sorry that the following has to be that ugly but some versions of GCC
@@ -231,7 +244,7 @@ static __always_inline void *kmalloc(size_t size, gfp_t flags)
         void *ret;
 
         if (__builtin_constant_p(size)) {
-                if (size > PAGE_SIZE)
+                if (size > SLUB_MAX_SIZE)
                         return kmalloc_large(size, flags);
 
                 if (!(flags & SLUB_DMA)) {
@@ -275,7 +288,7 @@ static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
         void *ret;
 
         if (__builtin_constant_p(size) &&
-                size <= PAGE_SIZE && !(flags & SLUB_DMA)) {
+                size <= SLUB_MAX_SIZE && !(flags & SLUB_DMA)) {
                         struct kmem_cache *s = kmalloc_slab(size);
 
                 if (!s)