From fd76bab2fa6d8f3ef6b326a4c6ae442fa21d30a4 Mon Sep 17 00:00:00 2001 From: Pekka Enberg Date: Sun, 6 May 2007 14:48:40 -0700 Subject: 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 Acked-by: Matt Mackall Acked-by: Christoph Lameter Signed-off-by: Pekka Enberg Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/slob.c | 35 ++++++++++++++++++++++++++++++++++- 1 file changed, 34 insertions(+), 1 deletion(-) (limited to 'mm/slob.c') diff --git a/mm/slob.c b/mm/slob.c index 5adc29cb58dd..03cce3d3d986 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; -- cgit v1.2.1