From a75c380c7129c432f8ac9d42ebc170e5f7d9d31e Mon Sep 17 00:00:00 2001 From: Anton Blanchard Date: Fri, 19 Sep 2014 09:40:21 +1000 Subject: [PATCH] powerpc: Enable DCACHE_WORD_ACCESS on ppc64le Enable on DCACHE_WORD_ACCESS on ppc64le. It should work on ppc64 and ppc32 but we need to do some testing first. A somewhat reasonable testcase used to show the performance improvement - a repeated stat of a 33 byte filename that doesn't exist: #include #include #include #define ITERATIONS 10000000 #define PATH "123456781234567812345678123456781" int main(void) { unsigned long i; struct stat buf; for (i = 0; i < ITERATIONS; i++) stat(PATH, &buf); return 0; } runs 27% faster on POWER8. Signed-off-by: Anton Blanchard Signed-off-by: Michael Ellerman --- arch/powerpc/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index ece1c01..56da472 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -147,6 +147,7 @@ config PPC select ARCH_USE_CMPXCHG_LOCKREF if PPC64 select HAVE_ARCH_AUDITSYSCALL select ARCH_SUPPORTS_ATOMIC_RMW + select DCACHE_WORD_ACCESS if PPC64 && CPU_LITTLE_ENDIAN config GENERIC_CSUM def_bool CPU_LITTLE_ENDIAN -- 2.7.4