diff options
| author | Christoph Lameter <cl@linux-foundation.org> | 2009-02-17 12:05:07 -0500 |
|---|---|---|
| committer | Pekka Enberg <penberg@cs.helsinki.fi> | 2009-02-20 12:28:36 +0200 |
| commit | fe1200b63d158b28eef6d4de1e5b5f99c681ba2f (patch) | |
| tree | bff176ef50efbc161e240ec4295a6da815eae997 /include/linux/slub_def.h | |
| parent | b578f3fcca1e78624dfb5f358776e63711d7fda2 (diff) | |
SLUB: Introduce and use SLUB_MAX_SIZE and SLUB_PAGE_SHIFT constants
As a preparational patch to bump up page allocator pass-through threshold,
introduce two new constants SLUB_MAX_SIZE and SLUB_PAGE_SHIFT and convert
mm/slub.c to use them.
Reported-by: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com>
Tested-by: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com>
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Diffstat (limited to 'include/linux/slub_def.h')
| -rw-r--r-- | include/linux/slub_def.h | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h index 2f5c16b1aac..986e09dcfd8 100644 --- a/include/linux/slub_def.h +++ b/include/linux/slub_def.h @@ -121,10 +121,23 @@ 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 @@ -212,7 +225,7 @@ static __always_inline void *kmalloc_large(size_t size, gfp_t flags) static __always_inline void *kmalloc(size_t size, gfp_t flags) { if (__builtin_constant_p(size)) { - if (size > PAGE_SIZE) + if (size > SLUB_MAX_SIZE) return kmalloc_large(size, flags); if (!(flags & SLUB_DMA)) { @@ -234,7 +247,7 @@ void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node); static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node) { 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) |