Gitweb:
http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=fd76bab2fa6d8f3ef6b326a4c6ae442fa21d30a4
Commit: fd76bab2fa6d8f3ef6b326a4c6ae442fa21d30a4
Parent: e3ebadd95cb621e2c7436f3d3646447ac9d5c16d
Author: Pekka Enberg <[EMAIL PROTECTED]>
AuthorDate: Sun May 6 14:48:40 2007 -0700
Committer: Linus Torvalds <[EMAIL PROTECTED]>
CommitDate: Mon May 7 12:12:50 2007 -0700
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.
[EMAIL PROTECTED]: fix warnings]
Acked-by: Josef Sipek <[EMAIL PROTECTED]>
Acked-by: Matt Mackall <[EMAIL PROTECTED]>
Acked-by: Christoph Lameter <[EMAIL PROTECTED]>
Signed-off-by: Pekka Enberg <[EMAIL PROTECTED]>
Signed-off-by: Andrew Morton <[EMAIL PROTECTED]>
Signed-off-by: Linus Torvalds <[EMAIL PROTECTED]>
---
include/linux/slab.h | 3 ++-
mm/slab.c | 49 ++++++++++++++++++++++++++++++++++++++++++++++++-
mm/slob.c | 35 ++++++++++++++++++++++++++++++++++-
3 files changed, 84 insertions(+), 3 deletions(-)
diff --git a/include/linux/slab.h b/include/linux/slab.h
index 1ef822e..2f8f60f 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -72,8 +72,9 @@ static inline void *kmem_cache_alloc_node(struct kmem_cache
*cachep,
*/
void *__kmalloc(size_t, gfp_t);
void *__kzalloc(size_t, gfp_t);
+void * __must_check krealloc(const void *, size_t, gfp_t);
void kfree(const void *);
-unsigned int ksize(const void *);
+size_t ksize(const void *);
/**
* kcalloc - allocate memory for an array. The memory is set to zero.
diff --git a/mm/slab.c b/mm/slab.c
index 168bfe9..8b71a9c 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -3740,6 +3740,53 @@ 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.
* @objp: The previously allocated object.
@@ -4481,7 +4528,7 @@ const struct seq_operations slabstats_op = {
* allocated with either kmalloc() or kmem_cache_alloc(). The object
* must not be freed during the duration of the call.
*/
-unsigned int ksize(const void *objp)
+size_t ksize(const void *objp)
{
if (unlikely(objp == NULL))
return 0;
diff --git a/mm/slob.c b/mm/slob.c
index 5adc29c..03cce3d 100644
--- a/mm/slob.c
+++ b/mm/slob.c
@@ -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;
-
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