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 <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#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 <an...@samba.org>
---
arch/powerpc/Kconfig | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 90fe77a..7992f35 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -148,6 +148,7 @@ config PPC
select HAVE_ARCH_AUDITSYSCALL
select ARCH_SUPPORTS_ATOMIC_RMW
select HAVE_PERF_EVENTS_NMI if PPC64
+ select DCACHE_WORD_ACCESS if PPC64 && CPU_LITTLE_ENDIAN
config GENERIC_CSUM
def_bool CPU_LITTLE_ENDIAN
--
1.9.1
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