diff options
| author | Christoph Lameter <clameter@sgi.com> | 2007-07-17 04:03:22 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-07-17 10:23:01 -0700 |
| commit | 6cb8f91320d3e720351c21741da795fed580b21b (patch) | |
| tree | c9f73c8b82cd0f6c534939b8b9f36e8615b0ab2d /mm/slab.c | |
| parent | ef2ad80c7d255ed0449eda947c2d700635b7e0f5 (diff) | |
| download | lwn-6cb8f91320d3e720351c21741da795fed580b21b.tar.gz lwn-6cb8f91320d3e720351c21741da795fed580b21b.zip | |
Slab allocators: consistent ZERO_SIZE_PTR support and NULL result semantics
Define ZERO_OR_NULL_PTR macro to be able to remove the checks from the
allocators. Move ZERO_SIZE_PTR related stuff into slab.h.
Make ZERO_SIZE_PTR work for all slab allocators and get rid of the
WARN_ON_ONCE(size == 0) that is still remaining in SLAB.
Make slub return NULL like the other allocators if a too large memory segment
is requested via __kmalloc.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/slab.c')
| -rw-r--r-- | mm/slab.c | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/mm/slab.c b/mm/slab.c index 4bd8a53091b7..d2cd304fd8af 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -775,6 +775,9 @@ static inline struct kmem_cache *__find_general_cachep(size_t size, */ BUG_ON(malloc_sizes[INDEX_AC].cs_cachep == NULL); #endif + if (!size) + return ZERO_SIZE_PTR; + while (size > csizep->cs_size) csizep++; @@ -2351,7 +2354,7 @@ kmem_cache_create (const char *name, size_t size, size_t align, * this should not happen at all. * But leave a BUG_ON for some lucky dude. */ - BUG_ON(!cachep->slabp_cache); + BUG_ON(ZERO_OR_NULL_PTR(cachep->slabp_cache)); } cachep->ctor = ctor; cachep->name = name; @@ -3653,8 +3656,8 @@ __do_kmalloc_node(size_t size, gfp_t flags, int node, void *caller) struct kmem_cache *cachep; cachep = kmem_find_general_cachep(size, flags); - if (unlikely(cachep == NULL)) - return NULL; + if (unlikely(ZERO_OR_NULL_PTR(cachep))) + return cachep; return kmem_cache_alloc_node(cachep, flags, node); } @@ -3760,7 +3763,7 @@ void kfree(const void *objp) struct kmem_cache *c; unsigned long flags; - if (unlikely(!objp)) + if (unlikely(ZERO_OR_NULL_PTR(objp))) return; local_irq_save(flags); kfree_debugcheck(objp); @@ -4447,7 +4450,7 @@ const struct seq_operations slabstats_op = { */ size_t ksize(const void *objp) { - if (unlikely(objp == NULL)) + if (unlikely(ZERO_OR_NULL_PTR(objp))) return 0; return obj_size(virt_to_cache(objp)); |