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authorChristoph Lameter <clameter@sgi.com>2007-07-17 04:03:22 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-07-17 10:23:01 -0700
commit6cb8f91320d3e720351c21741da795fed580b21b (patch)
treec9f73c8b82cd0f6c534939b8b9f36e8615b0ab2d /mm/slab.c
parentef2ad80c7d255ed0449eda947c2d700635b7e0f5 (diff)
downloadlinux-6cb8f91320d3e720351c21741da795fed580b21b.tar.bz2
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.c13
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));