2007-08-13 15:17:36

by vignesh babu

[permalink] [raw]
Subject: [kj] is_power_of_2 in mm/slub.c

Replacing n & (n - 1) for power of 2 check by is_power_of_2(n)

Signed-off-by: vignesh babu <[email protected]>
---
diff --git a/mm/slub.c b/mm/slub.c
index 69d02e3..1241d14 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -20,6 +20,7 @@
#include <linux/mempolicy.h>
#include <linux/ctype.h>
#include <linux/kallsyms.h>
+#include <linux/log2.h>

/*
* Lock order:
@@ -2606,7 +2607,7 @@ void __init kmem_cache_init(void)
* around with ARCH_KMALLOC_MINALIGN
*/
BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 ||
- (KMALLOC_MIN_SIZE & (KMALLOC_MIN_SIZE - 1)));
+ !is_power_of_2(KMALLOC_MIN_SIZE));

for (i = 8; i < KMALLOC_MIN_SIZE; i += 8)
size_index[(i - 1) / 8] = KMALLOC_SHIFT_LOW;

--
Vignesh Babu BM
_____________________________________________________________
"Why is it that every time I'm with you, makes me believe in magic?"


2007-08-13 20:48:50

by Christoph Lameter

[permalink] [raw]
Subject: Re: [kj] is_power_of_2 in mm/slub.c

Acked-by: Christoph Lameter <[email protected]>