From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx152.postini.com [74.125.245.152]) by kanga.kvack.org (Postfix) with SMTP id 32CA16B006C for ; Sun, 26 Aug 2012 05:00:50 -0400 (EDT) Received: from /spool/local by e28smtp03.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Sun, 26 Aug 2012 14:30:46 +0530 Received: from d28av05.in.ibm.com (d28av05.in.ibm.com [9.184.220.67]) by d28relay01.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q7Q90jxg53411842 for ; Sun, 26 Aug 2012 14:30:45 +0530 Received: from d28av05.in.ibm.com (loopback [127.0.0.1]) by d28av05.in.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q7Q90iN7012105 for ; Sun, 26 Aug 2012 19:00:45 +1000 From: Wanpeng Li Subject: [PATCH v2 1/4] mm/memblock: reduce overhead in binary search Date: Sun, 26 Aug 2012 17:00:23 +0800 Message-Id: <1345971626-17090-1-git-send-email-liwanp@linux.vnet.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Michal Hocko , KAMEZAWA Hiroyuki , Minchan Kim , Gavin Shan , Wanpeng Li "v1 -> v2": * move check from memblock_search to memblock_is_memory * modify changelog When checking the indicated address belongs to the memory region, the memory 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 | 5 +++++ 1 files changed, 5 insertions(+), 0 deletions(-) diff --git a/mm/memblock.c b/mm/memblock.c index 4d9393c..258e81d 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -888,6 +888,11 @@ int __init memblock_is_reserved(phys_addr_t addr) int __init_memblock memblock_is_memory(phys_addr_t addr) { + + if (unlikely(addr < memblock_start_of_DRAM() || + addr >= memblock_end_of_DRAM())) + return 0; + return memblock_search(&memblock.memory, addr) != -1; } -- 1.7.5.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org