diff options
author | Anton Blanchard <anton@samba.org> | 2010-02-10 18:07:54 +0000 |
---|---|---|
committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2010-02-17 14:03:16 +1100 |
commit | 63e6c5b8102af7df7a5e1cebbd865d711645886a (patch) | |
tree | 8dd79a95cf5265b6e1d88bed1493c0b952d23992 /arch/powerpc/lib/copypage_64.S | |
parent | 5a0e9b5718d921f5d8e17176d6b483f6b8f1844a (diff) | |
download | linux-63e6c5b8102af7df7a5e1cebbd865d711645886a.tar.bz2 |
powerpc: Pair loads and stores in copy_4k_page
A number of our chips like loads and stores to be paired. A small kernel
module testcase shows the improvement of pairing loads and stores in
copy_4k_page:
POWER6: +9%
POWER7: +1.5%
#include <linux/module.h>
#include <linux/mm.h>
#define ITERATIONS 10000000
static int __init copypage_init(void)
{
struct timespec before, after;
unsigned long i;
struct page *destpage, *srcpage;
char *dest, *src;
destpage = alloc_page(GFP_KERNEL);
srcpage = alloc_page(GFP_KERNEL);
dest = page_address(destpage);
src = page_address(srcpage);
getnstimeofday(&before);
for (i = 0; i < ITERATIONS; i++)
copy_4K_page(dest, src);
getnstimeofday(&after);
free_page((unsigned long)dest);
free_page((unsigned long)src);
printk(KERN_DEBUG "copy_4K_page loop took %lu ns\n",
(after.tv_sec - before.tv_sec) * NSEC_PER_SEC +
(after.tv_nsec - before.tv_nsec));
return 0;
}
static void __exit copypage_exit(void)
{
}
module_init(copypage_init)
module_exit(copypage_exit)
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Anton Blanchard");
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/lib/copypage_64.S')
-rw-r--r-- | arch/powerpc/lib/copypage_64.S | 28 |
1 files changed, 14 insertions, 14 deletions
diff --git a/arch/powerpc/lib/copypage_64.S b/arch/powerpc/lib/copypage_64.S index e68beac0a171..4d4eeb900486 100644 --- a/arch/powerpc/lib/copypage_64.S +++ b/arch/powerpc/lib/copypage_64.S @@ -43,62 +43,62 @@ END_FTR_SECTION_IFSET(CPU_FTR_CP_USE_DCBTZ) ld r7,16(r4) ldu r8,24(r4) 1: std r5,8(r3) - ld r9,8(r4) std r6,16(r3) + ld r9,8(r4) ld r10,16(r4) std r7,24(r3) - ld r11,24(r4) std r8,32(r3) + ld r11,24(r4) ld r12,32(r4) std r9,40(r3) - ld r5,40(r4) std r10,48(r3) + ld r5,40(r4) ld r6,48(r4) std r11,56(r3) - ld r7,56(r4) std r12,64(r3) + ld r7,56(r4) ld r8,64(r4) std r5,72(r3) - ld r9,72(r4) std r6,80(r3) + ld r9,72(r4) ld r10,80(r4) std r7,88(r3) - ld r11,88(r4) std r8,96(r3) + ld r11,88(r4) ld r12,96(r4) std r9,104(r3) - ld r5,104(r4) std r10,112(r3) + ld r5,104(r4) ld r6,112(r4) std r11,120(r3) - ld r7,120(r4) stdu r12,128(r3) + ld r7,120(r4) ldu r8,128(r4) bdnz 1b std r5,8(r3) - ld r9,8(r4) std r6,16(r3) + ld r9,8(r4) ld r10,16(r4) std r7,24(r3) - ld r11,24(r4) std r8,32(r3) + ld r11,24(r4) ld r12,32(r4) std r9,40(r3) - ld r5,40(r4) std r10,48(r3) + ld r5,40(r4) ld r6,48(r4) std r11,56(r3) - ld r7,56(r4) std r12,64(r3) + ld r7,56(r4) ld r8,64(r4) std r5,72(r3) - ld r9,72(r4) std r6,80(r3) + ld r9,72(r4) ld r10,80(r4) std r7,88(r3) - ld r11,88(r4) std r8,96(r3) + ld r11,88(r4) ld r12,96(r4) std r9,104(r3) std r10,112(r3) |