Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933006Ab2HXOe4 (ORCPT ); Fri, 24 Aug 2012 10:34:56 -0400 Received: from e28smtp04.in.ibm.com ([122.248.162.4]:60670 "EHLO e28smtp04.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932612Ab2HXOey (ORCPT ); Fri, 24 Aug 2012 10:34:54 -0400 From: Wanpeng Li To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, Michal Hocko , KAMEZAWA Hiroyuki , Minchan Kim , Andrew Morton , Gavin Shan , Wanpeng Li Subject: [PATCH 3/5] mm/memblock: reduce overhead in binary search Date: Fri, 24 Aug 2012 22:33:38 +0800 Message-Id: <1345818820-12102-3-git-send-email-liwanp@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.5.4 In-Reply-To: <1345818820-12102-1-git-send-email-liwanp@linux.vnet.ibm.com> References: <1345818820-12102-1-git-send-email-liwanp@linux.vnet.ibm.com> x-cbid: 12082414-5564-0000-0000-0000042C6034 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1217 Lines: 37 From: Wanpeng Li When checking the indicated address belongs to the memory or reserved region, the memory or reserved regions are checked one by one through binary search, which would be a little time consuming. If the indicated address isn't in memory region, then we needn't do the time-sonsuming search. The patch adds more check on the indicated address for that purpose. Signed-off-by: Wanpeng Li --- mm/memblock.c | 4 ++++ 1 files changed, 4 insertions(+), 0 deletions(-) diff --git a/mm/memblock.c b/mm/memblock.c index 2feff8d..880e461 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -871,6 +871,10 @@ static int __init_memblock memblock_search(struct memblock_type *type, phys_addr { unsigned int left = 0, right = type->cnt; + if (unlikely(addr < memblock_start_of_DRAM() || + addr >= memblock_end_of_DRAM())) + return 0; + do { unsigned int mid = (right + left) / 2; -- 1.7.5.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/