The patch titled
slab: introduce krealloc
has been added to the -mm tree. Its filename is
slab-introduce-krealloc.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: slab: introduce krealloc
From: Pekka Enberg <penberg@xxxxxxxxxxxxxx>
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.
Acked-by: Josef Sipek <jsipek@xxxxxxxxxxxxxxxxx>
Acked-by: Matt Mackall <mpm@xxxxxxxxxxx>
Acked-by: Christoph Lameter <clameter@xxxxxxx>
Signed-off-by: Pekka Enberg <penberg@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/slab.h | 1
mm/slab.c | 47 +++++++++++++++++++++++++++++++++++++++++
mm/slob.c | 33 ++++++++++++++++++++++++++++
3 files changed, 81 insertions(+)
diff -puN include/linux/slab.h~slab-introduce-krealloc include/linux/slab.h
--- a/include/linux/slab.h~slab-introduce-krealloc
+++ a/include/linux/slab.h
@@ -72,6 +72,7 @@ static inline void *kmem_cache_alloc_nod
*/
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 *);
diff -puN mm/slab.c~slab-introduce-krealloc mm/slab.c
--- a/mm/slab.c~slab-introduce-krealloc
+++ a/mm/slab.c
@@ -3737,6 +3737,53 @@ 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.
diff -puN mm/slob.c~slab-introduce-krealloc mm/slob.c
--- a/mm/slob.c~slab-introduce-krealloc
+++ a/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;
_
Patches currently in -mm which might be from penberg@xxxxxxxxxxxxxx are
slab-introduce-krealloc.patch
unionfs-fix-slab-abuses-with-krealloc.patch
slab-ensure-cache_alloc_refill-terminates.patch
slab-remove-colouroff-from-struct-slab.patch
module-use-krealloc.patch
slab-use-cpu_lock_.patch
slab-leaks3-default-y.patch
-
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
