diff options
Diffstat (limited to 'crypto/xor.c')
| -rw-r--r-- | crypto/xor.c | 32 |
1 files changed, 23 insertions, 9 deletions
diff --git a/crypto/xor.c b/crypto/xor.c index b2e6db075e4..35d6b3adf23 100644 --- a/crypto/xor.c +++ b/crypto/xor.c @@ -18,8 +18,10 @@ #define BH_TRACE 0 #include <linux/module.h> -#include <linux/raid/md.h> +#include <linux/gfp.h> #include <linux/raid/xor.h> +#include <linux/jiffies.h> +#include <linux/preempt.h> #include <asm/xor.h> /* The xor routines to use. */ @@ -54,20 +56,22 @@ xor_blocks(unsigned int src_count, unsigned int bytes, void *dest, void **srcs) EXPORT_SYMBOL(xor_blocks); /* Set of all registered templates. */ -static struct xor_block_template *template_list; +static struct xor_block_template *__initdata template_list; #define BENCH_SIZE (PAGE_SIZE) -static void +static void __init do_xor_speed(struct xor_block_template *tmpl, void *b1, void *b2) { int speed; - unsigned long now; + unsigned long now, j; int i, count, max; tmpl->next = template_list; template_list = tmpl; + preempt_disable(); + /* * Count the number of XORs done during a whole jiffy, and use * this to calculate the speed of checksumming. We use a 2-page @@ -75,9 +79,11 @@ do_xor_speed(struct xor_block_template *tmpl, void *b1, void *b2) */ max = 0; for (i = 0; i < 5; i++) { - now = jiffies; + j = jiffies; count = 0; - while (jiffies == now) { + while ((now = jiffies) == j) + cpu_relax(); + while (time_before(jiffies, now + 1)) { mb(); /* prevent loop optimzation */ tmpl->do_2(BENCH_SIZE, b1, b2); mb(); @@ -88,6 +94,8 @@ do_xor_speed(struct xor_block_template *tmpl, void *b1, void *b2) max = count; } + preempt_enable(); + speed = max * (HZ * BENCH_SIZE / 1024); tmpl->speed = speed; @@ -101,7 +109,12 @@ calibrate_xor_blocks(void) void *b1, *b2; struct xor_block_template *f, *fastest; - b1 = (void *) __get_free_pages(GFP_KERNEL, 2); + /* + * Note: Since the memory is not actually used for _anything_ but to + * test the XOR speed, we don't really want kmemcheck to warn about + * reading uninitialized bytes here. + */ + b1 = (void *) __get_free_pages(GFP_KERNEL | __GFP_NOTRACK, 2); if (!b1) { printk(KERN_WARNING "xor: Yikes! No memory available.\n"); return -ENOMEM; @@ -123,9 +136,9 @@ calibrate_xor_blocks(void) if (fastest) { printk(KERN_INFO "xor: automatically using best " - "checksumming function: %s\n", - fastest->name); + "checksumming function:\n"); xor_speed(fastest); + goto out; } else { printk(KERN_INFO "xor: measuring software checksum speed\n"); XOR_TRY_TEMPLATES; @@ -140,6 +153,7 @@ calibrate_xor_blocks(void) #undef xor_speed + out: free_pages((unsigned long)b1, 2); active_template = fastest; |