slab: introduce krealloc

This introduce krealloc() that reallocates memory while keeping the contents
unchanged.  The allocator avoids reallocation if the new size fits the
currently used cache.  I also added a simple non-optimized version for
mm/slob.c for compatibility.

[akpm@linux-foundation.org: fix warnings]
Acked-by: Josef Sipek <jsipek@fsl.cs.sunysb.edu>
Acked-by: Matt Mackall <mpm@selenic.com>
Acked-by: Christoph Lameter <clameter@sgi.com>
Signed-off-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>
This commit is contained in:
Pekka Enberg
2007-05-06 14:48:40 -07:00
committed by Linus Torvalds
parent e3ebadd95c
commit fd76bab2fa
3 changed files with 84 additions and 3 deletions

View File

@@ -190,6 +190,39 @@ void *__kmalloc(size_t size, gfp_t gfp)
}
EXPORT_SYMBOL(__kmalloc);
/**
* 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)
{
bigblock_t *bb, **last = &bigblocks;
@@ -219,7 +252,7 @@ void kfree(const void *block)
EXPORT_SYMBOL(kfree);
unsigned int ksize(const void *block)
size_t ksize(const void *block)
{
bigblock_t *bb;
unsigned long flags;