Commit 2408c550 authored by Satyam Sharma's avatar Satyam Sharma Committed by Linus Torvalds
Browse files

{slub, slob}: use unlikely() for kfree(ZERO_OR_NULL_PTR) check 



Considering kfree(NULL) would normally occur only in error paths and
kfree(ZERO_SIZE_PTR) is uncommon as well, so let's use unlikely() for the
condition check in SLUB's and SLOB's kfree() to optimize for the common
case.  SLAB has this already.

Signed-off-by: default avatarSatyam Sharma <satyam@infradead.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent c92ff1bd

mm/slob.c

+3 −3
Original line number Diff line number Diff line
@@ -360,7 +360,7 @@ static void slob_free(void *block, int size) 
	slobidx_t units;

	unsigned long flags;



	if (ZERO_OR_NULL_PTR(block))

	if (unlikely(ZERO_OR_NULL_PTR(block)))

		return;

	BUG_ON(!size);
@@ -466,7 +466,7 @@ void kfree(const void *block) 
{

	struct slob_page *sp;



	if (ZERO_OR_NULL_PTR(block))

	if (unlikely(ZERO_OR_NULL_PTR(block)))

		return;



	sp = (struct slob_page *)virt_to_page(block);
@@ -484,7 +484,7 @@ size_t ksize(const void *block) 
{

	struct slob_page *sp;



	if (ZERO_OR_NULL_PTR(block))

	if (unlikely(ZERO_OR_NULL_PTR(block)))

		return 0;



	sp = (struct slob_page *)virt_to_page(block);

mm/slub.c

+4 −4
Original line number Diff line number Diff line
@@ -2449,7 +2449,7 @@ size_t ksize(const void *object) 
	struct page *page;

	struct kmem_cache *s;



	if (ZERO_OR_NULL_PTR(object))

	if (unlikely(ZERO_OR_NULL_PTR(object)))

		return 0;



	page = get_object_page(object);
@@ -2483,7 +2483,7 @@ void kfree(const void *x) 
{

	struct page *page;



	if (ZERO_OR_NULL_PTR(x))

	if (unlikely(ZERO_OR_NULL_PTR(x)))

		return;



	page = virt_to_head_page(x);
@@ -2800,7 +2800,7 @@ void *__kmalloc_track_caller(size_t size, gfp_t gfpflags, void *caller) 
							get_order(size));

	s = get_slab(size, gfpflags);



	if (ZERO_OR_NULL_PTR(s))

	if (unlikely(ZERO_OR_NULL_PTR(s)))

		return s;



	return slab_alloc(s, gfpflags, -1, caller);
@@ -2816,7 +2816,7 @@ void *__kmalloc_node_track_caller(size_t size, gfp_t gfpflags, 
							get_order(size));

	s = get_slab(size, gfpflags);



	if (ZERO_OR_NULL_PTR(s))

	if (unlikely(ZERO_OR_NULL_PTR(s)))

		return s;



	return slab_alloc(s, gfpflags, node, caller);

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