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Commit ef2ad80c authored by Christoph Lameter's avatar Christoph Lameter Committed by Linus Torvalds
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Slab allocators: consolidate code for krealloc in mm/util.c 



The size of a kmalloc object is readily available via ksize().  ksize is
provided by all allocators and thus we can implement krealloc in a generic
way.

Implement krealloc in mm/util.c and drop slab specific implementations of
krealloc.

Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
Acked-by: default avatarPekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent d45f39cb

mm/slab.c

+0 −46
Original line number Diff line number Diff line
@@ -3725,52 +3725,6 @@ void *__kmalloc(size_t size, gfp_t flags) 
EXPORT_SYMBOL(__kmalloc);

#endif



/**

 * krealloc - reallocate memory. The contents will remain unchanged.

 * @p: object to reallocate memory for.

 * @new_size: how many bytes of memory are required.

 * @flags: the type of memory to allocate.

 *

 * The contents of the object pointed to are preserved up to the

 * lesser of the new and old sizes.  If @p is %NULL, krealloc()

 * behaves exactly like kmalloc().  If @size is 0 and @p is not a

 * %NULL pointer, the object pointed to is freed.

 */

void *krealloc(const void *p, size_t new_size, gfp_t flags)

{

	struct kmem_cache *cache, *new_cache;

	void *ret;



	if (unlikely(!p))

		return kmalloc_track_caller(new_size, flags);



	if (unlikely(!new_size)) {

		kfree(p);

		return NULL;

	}



	cache = virt_to_cache(p);

	new_cache = __find_general_cachep(new_size, flags);



	/*

 	 * If new size fits in the current cache, bail out.

 	 */

	if (likely(cache == new_cache))

		return (void *)p;



	/*

 	 * We are on the slow-path here so do not use __cache_alloc

 	 * because it bloats kernel text.

 	 */

	ret = kmalloc_track_caller(new_size, flags);

	if (ret) {

		memcpy(ret, p, min(new_size, ksize(p)));

		kfree(p);

	}

	return ret;

}

EXPORT_SYMBOL(krealloc);



/**

 * kmem_cache_free - Deallocate an object

 * @cachep: The cache the allocation was from.

mm/slob.c

+0 −33
Original line number Diff line number Diff line
@@ -446,39 +446,6 @@ void *__kmalloc_node(size_t size, gfp_t gfp, int node) 
}

EXPORT_SYMBOL(__kmalloc_node);



/**

 * krealloc - reallocate memory. The contents will remain unchanged.

 *

 * @p: object to reallocate memory for.

 * @new_size: how many bytes of memory are required.

 * @flags: the type of memory to allocate.

 *

 * The contents of the object pointed to are preserved up to the

 * lesser of the new and old sizes.  If @p is %NULL, krealloc()

 * behaves exactly like kmalloc().  If @size is 0 and @p is not a

 * %NULL pointer, the object pointed to is freed.

 */

void *krealloc(const void *p, size_t new_size, gfp_t flags)

{

	void *ret;



	if (unlikely(!p))

		return kmalloc_track_caller(new_size, flags);



	if (unlikely(!new_size)) {

		kfree(p);

		return NULL;

	}



	ret = kmalloc_track_caller(new_size, flags);

	if (ret) {

		memcpy(ret, p, min(new_size, ksize(p)));

		kfree(p);

	}

	return ret;

}

EXPORT_SYMBOL(krealloc);



void kfree(const void *block)

{

	struct slob_page *sp;

mm/slub.c

+0 −37
Original line number Diff line number Diff line
@@ -2467,43 +2467,6 @@ int kmem_cache_shrink(struct kmem_cache *s) 
}

EXPORT_SYMBOL(kmem_cache_shrink);



/**

 * krealloc - reallocate memory. The contents will remain unchanged.

 * @p: object to reallocate memory for.

 * @new_size: how many bytes of memory are required.

 * @flags: the type of memory to allocate.

 *

 * The contents of the object pointed to are preserved up to the

 * lesser of the new and old sizes.  If @p is %NULL, krealloc()

 * behaves exactly like kmalloc().  If @size is 0 and @p is not a

 * %NULL pointer, the object pointed to is freed.

 */

void *krealloc(const void *p, size_t new_size, gfp_t flags)

{

	void *ret;

	size_t ks;



	if (unlikely(!p || p == ZERO_SIZE_PTR))

		return kmalloc(new_size, flags);



	if (unlikely(!new_size)) {

		kfree(p);

		return ZERO_SIZE_PTR;

	}



	ks = ksize(p);

	if (ks >= new_size)

		return (void *)p;



	ret = kmalloc(new_size, flags);

	if (ret) {

		memcpy(ret, p, min(new_size, ks));

		kfree(p);

	}

	return ret;

}

EXPORT_SYMBOL(krealloc);



/********************************************************************

 *			Basic setup of slabs

 *******************************************************************/

mm/util.c

+34 −0
Original line number Diff line number Diff line
@@ -58,6 +58,40 @@ void *kmemdup(const void *src, size_t len, gfp_t gfp) 
}

EXPORT_SYMBOL(kmemdup);



/**

 * krealloc - reallocate memory. The contents will remain unchanged.

 * @p: object to reallocate memory for.

 * @new_size: how many bytes of memory are required.

 * @flags: the type of memory to allocate.

 *

 * The contents of the object pointed to are preserved up to the

 * lesser of the new and old sizes.  If @p is %NULL, krealloc()

 * behaves exactly like kmalloc().  If @size is 0 and @p is not a

 * %NULL pointer, the object pointed to is freed.

 */

void *krealloc(const void *p, size_t new_size, gfp_t flags)

{

	void *ret;

	size_t ks;



	if (unlikely(!new_size)) {

		kfree(p);

		return NULL;

	}



	ks = ksize(p);

	if (ks >= new_size)

		return (void *)p;



	ret = kmalloc_track_caller(new_size, flags);

	if (ret) {

		memcpy(ret, p, min(new_size, ks));

		kfree(p);

	}

	return ret;

}

EXPORT_SYMBOL(krealloc);



/*

 * strndup_user - duplicate an existing string from user space

 *