From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 587101A0929 for ; Fri, 19 Sep 2014 09:40:28 +1000 (EST) From: Anton Blanchard To: benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au, amodra@gmail.com, torvalds@linux-foundation.org Subject: [PATCH 3/3] powerpc: Enable DCACHE_WORD_ACCESS on ppc64le Date: Fri, 19 Sep 2014 09:40:21 +1000 Message-Id: <1411083621-12064-4-git-send-email-anton@samba.org> In-Reply-To: <1411083621-12064-1-git-send-email-anton@samba.org> References: <1411083621-12064-1-git-send-email-anton@samba.org> Cc: linuxppc-dev@lists.ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 --- 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