Commit a75c380c authored by Anton Blanchard's avatar Anton Blanchard Committed by Michael Ellerman

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 <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: default avatarAnton Blanchard <anton@samba.org>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 8989aa4a
...@@ -147,6 +147,7 @@ config PPC ...@@ -147,6 +147,7 @@ config PPC
select ARCH_USE_CMPXCHG_LOCKREF if PPC64 select ARCH_USE_CMPXCHG_LOCKREF if PPC64
select HAVE_ARCH_AUDITSYSCALL select HAVE_ARCH_AUDITSYSCALL
select ARCH_SUPPORTS_ATOMIC_RMW select ARCH_SUPPORTS_ATOMIC_RMW
select DCACHE_WORD_ACCESS if PPC64 && CPU_LITTLE_ENDIAN
config GENERIC_CSUM config GENERIC_CSUM
def_bool CPU_LITTLE_ENDIAN def_bool CPU_LITTLE_ENDIAN
......
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