redonkable/alistair23-linux
redonkable/alistair23-linux
1
0
Fork 0
Code Releases Activity
alistair23-linux/arch
History
Anton Blanchard 63e6c5b810 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>
2010-02-17 14:03:16 +11:00
..
alpha alpha: cpumask_of_node() should handle -1 as a node 2010-01-14 13:21:35 -05:00
arm OMAP: hsmmc: fix memory leak 2010-02-10 09:20:33 -08:00
avr32
blackfin blackfin,kgdb: Do not put PC in gdb_regs into retx. 2010-01-07 11:58:37 -06:00
cris
frv FDPIC: Respect PT_GNU_STACK exec protection markings when creating NOMMU stack 2010-01-06 18:16:02 -08:00
h8300
ia64 [IA64] preserve personality flag bits across exec 2010-02-12 08:17:58 -08:00
m32r
m68k m68knommu: fix definitions of __pa() and __va() 2010-01-12 20:51:45 -08:00
m68knommu m68knommu: fix invalid flags on coldfire pit clocksource 2010-01-16 12:15:38 -08:00
microblaze microblaze: Invalidate dcache before enabling it 2010-02-08 11:39:18 +01:00
mips MIPS: Don't probe reserved EntryHi bits. 2010-02-10 22:15:46 +01:00
mn10300 mn10300: update the ASB2303 defconfig 2010-01-11 09:34:10 -08:00
parisc parisc: fix tracing of signals 2010-02-12 08:51:58 -08:00
powerpc powerpc: Pair loads and stores in copy_4k_page 2010-02-17 14:03:16 +11:00
s390 [S390] Fix struct _lowcore layout. 2010-02-09 09:46:23 +01:00
score mm: make totalhigh_pages unsigned long 2010-01-11 09:34:03 -08:00
sh sh64: fix tracing of signals. 2010-02-15 14:17:45 +09:00
sparc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6 2010-02-11 14:00:27 -08:00
um Unrot uml mconsole a bit 2010-01-14 09:05:26 -05:00
x86 x86: ELF_PLAT_INIT() shouldn't worry about TIF_IA32 2010-02-16 08:51:49 -08:00
xtensa
.gitignore
Kconfig