From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761957AbXFRKMr (ORCPT ); Mon, 18 Jun 2007 06:12:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1762654AbXFRKFU (ORCPT ); Mon, 18 Jun 2007 06:05:20 -0400 Received: from qb-out-0506.google.com ([72.14.204.239]:25818 "EHLO qb-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1762640AbXFRKFR (ORCPT ); Mon, 18 Jun 2007 06:05:17 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:subject:from:to:cc:date:message-id; b=d9PSKMSmBDrSxGrfsD5CZP9xbAHx4mzyu27vquC9NvZeGrk0uyppJxCK05/ooq+0e/AXMoLnJpRDUkRnYnxwMeIY9Ae3c4zp3w4OeiYHWkdLOLY7km9MeoYzXRRn/iJNEL2rEUJcC2x7diAa0ex0MOR1QyixIDU570eRZxuJ0iY= Subject: [PATCH] trivial: the memset operation on a automatic array variable should be optimized out by data initialization From: Denis Cheng To: trivial@kernel.org Cc: linux-kernel@vger.kernel.org Date: Mon, 18 Jun 2007 03:05:15 -0700 (PDT) Message-ID: <467658db.0f98600a.5a55.ffffdd79@mx.google.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org From: Denis Cheng the explicit memset call could be optimized out by data initialization, thus all the fill working can be done by the compiler implicitly. Signed-off-by: Denis Cheng --- Is there some comments on this? --- arch/x86_64/mm/init.c.orig 2007-06-07 10:08:04.000000000 +0800 +++ arch/x86_64/mm/init.c 2007-06-18 14:43:15.000000000 +0800 @@ -406,8 +406,7 @@ void __cpuinit zap_low_mappings(int cpu) #ifndef CONFIG_NUMA void __init paging_init(void) { - unsigned long max_zone_pfns[MAX_NR_ZONES]; - memset(max_zone_pfns, 0, sizeof(max_zone_pfns)); + unsigned long max_zone_pfns[MAX_NR_ZONES] = { 0, }; max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN; max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN; max_zone_pfns[ZONE_NORMAL] = end_pfn;