From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755787Ab3KVR2l (ORCPT ); Fri, 22 Nov 2013 12:28:41 -0500 Received: from pegase1.c-s.fr ([93.17.236.30]:43852 "EHLO mailhub1.si.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755413Ab3KVR2k (ORCPT ); Fri, 22 Nov 2013 12:28:40 -0500 From: Christophe Leroy To: Benjamin Herrenschmidt , Paul Mackerras CC: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Joakim Tjernlund , scottwood@freescale.com Subject: [PATCH v2] powerpc 8xx: defconfig: slice by 4 is more efficient than the default slice by 8 on Powerpc 8xx. Message-Id: <20131122172829.CC8EE1A4DE7@localhost.localdomain> Date: Fri, 22 Nov 2013 18:28:29 +0100 (CET) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On PPC_8xx, CRC32_SLICEBY4 is more efficient (almost twice) than CRC32_SLICEBY8, as shown below: With CRC32_SLICEBY8: [ 1.109204] crc32: CRC_LE_BITS = 64, CRC_BE BITS = 64 [ 1.114401] crc32: self tests passed, processed 225944 bytes in 15118910 nsec [ 1.130655] crc32c: CRC_LE_BITS = 64 [ 1.134235] crc32c: self tests passed, processed 225944 bytes in 4479879 nsec With CRC32_SLICEBY4: [ 1.097129] crc32: CRC_LE_BITS = 32, CRC_BE BITS = 32 [ 1.101878] crc32: self tests passed, processed 225944 bytes in 8616242 nsec [ 1.116298] crc32c: CRC_LE_BITS = 32 [ 1.119607] crc32c: self tests passed, processed 225944 bytes in 3289576 nsec Signed-off-by: Christophe Leroy diff -ur a/arch/powerpc/configs/adder875_defconfig b/arch/powerpc/configs.new/adder875_defconfig --- a/arch/powerpc/configs/adder875_defconfig 2013-11-22 18:20:10.342968268 +0100 +++ b/arch/powerpc/configs.new/adder875_defconfig 2013-11-22 18:17:46.499686457 +0100 @@ -70,3 +70,4 @@ CONFIG_DETECT_HUNG_TASK=y CONFIG_DEBUG_INFO=y # CONFIG_RCU_CPU_STALL_DETECTOR is not set +CONFIG_CRC32_SLICEBY4=y diff -ur a/arch/powerpc/configs/ep88xc_defconfig b/arch/powerpc/configs.new/ep88xc_defconfig --- a/arch/powerpc/configs/ep88xc_defconfig 2013-11-22 18:20:10.286961148 +0100 +++ b/arch/powerpc/configs.new/ep88xc_defconfig 2013-11-22 18:17:41.992113565 +0100 @@ -72,3 +72,4 @@ CONFIG_DETECT_HUNG_TASK=y CONFIG_DEBUG_INFO=y # CONFIG_RCU_CPU_STALL_DETECTOR is not set +CONFIG_CRC32_SLICEBY4=y diff -ur a/arch/powerpc/configs/mpc866_ads_defconfig b/arch/powerpc/configs.new/mpc866_ads_defconfig --- a/arch/powerpc/configs/mpc866_ads_defconfig 2013-11-22 18:20:10.323965853 +0100 +++ b/arch/powerpc/configs.new/mpc866_ads_defconfig 2013-11-22 18:17:32.480904735 +0100 @@ -55,3 +55,4 @@ CONFIG_CRC_CCITT=y # CONFIG_RCU_CPU_STALL_DETECTOR is not set # CONFIG_CRYPTO_ANSI_CPRNG is not set +CONFIG_CRC32_SLICEBY4=y diff -ur a/arch/powerpc/configs/mpc885_ads_defconfig b/arch/powerpc/configs.new/mpc885_ads_defconfig --- a/arch/powerpc/configs/mpc885_ads_defconfig 2013-11-22 18:20:10.326966235 +0100 +++ b/arch/powerpc/configs.new/mpc885_ads_defconfig 2013-11-22 18:17:25.760050546 +0100 @@ -78,3 +78,4 @@ CONFIG_DETECT_HUNG_TASK=y CONFIG_DEBUG_INFO=y # CONFIG_RCU_CPU_STALL_DETECTOR is not set +CONFIG_CRC32_SLICEBY4=y diff -ur a/arch/powerpc/configs/tqm8xx_defconfig b/arch/powerpc/configs.new/tqm8xx_defconfig --- a/arch/powerpc/configs/tqm8xx_defconfig 2013-11-22 18:20:10.317965090 +0100 +++ b/arch/powerpc/configs.new/tqm8xx_defconfig 2013-11-22 18:17:14.926673681 +0100 @@ -84,3 +84,4 @@ CONFIG_DETECT_HUNG_TASK=y CONFIG_DEBUG_INFO=y # CONFIG_RCU_CPU_STALL_DETECTOR is not set +CONFIG_CRC32_SLICEBY4=y