From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758035AbZCMFhd (ORCPT ); Fri, 13 Mar 2009 01:37:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757909AbZCMFhK (ORCPT ); Fri, 13 Mar 2009 01:37:10 -0400 Received: from hera.kernel.org ([140.211.167.34]:46001 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757852AbZCMFhJ (ORCPT ); Fri, 13 Mar 2009 01:37:09 -0400 Message-ID: <49B9F0C1.10402@kernel.org> Date: Thu, 12 Mar 2009 22:36:01 -0700 From: Yinghai Lu User-Agent: Thunderbird 2.0.0.19 (X11/20081227) MIME-Version: 1.0 To: Ingo Molnar , Thomas Gleixner , "H. Peter Anvin" CC: jbeulich@novell.com, "linux-kernel@vger.kernel.org" Subject: [PATCH] x86: make e820_update_range to handle small range update References: <49B9E286.502@kernel.org> In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Impact: enhance to handle more case. try to handle new range could be covered by one entry. Signed-off-by: Yinghai Lu --- arch/x86/kernel/e820.c | 23 +++++++++++++++++++---- 1 file changed, 19 insertions(+), 4 deletions(-) Index: linux-2.6/arch/x86/kernel/e820.c =================================================================== --- linux-2.6.orig/arch/x86/kernel/e820.c +++ linux-2.6/arch/x86/kernel/e820.c @@ -427,6 +427,7 @@ static u64 __init __e820_update_range(st u64 size, unsigned old_type, unsigned new_type) { + u64 end; unsigned int i; u64 real_updated_size = 0; @@ -435,21 +436,35 @@ static u64 __init __e820_update_range(st if (size > (ULLONG_MAX - start)) size = ULLONG_MAX - start; + end = start + size; for (i = 0; i < e820x->nr_map; i++) { struct e820entry *ei = &e820x->map[i]; u64 final_start, final_end; + u64 ei_end; + if (ei->type != old_type) continue; - /* totally covered? */ - if (ei->addr >= start && - (ei->addr + ei->size) <= (start + size)) { + + ei_end = ei->addr + ei->size; + /* totally covered by new range? */ + if (ei->addr >= start && ei_end <= end) { ei->type = new_type; real_updated_size += ei->size; continue; } + + /* new range is totally covered? */ + if (ei->addr < start && ei_end > end) { + __e820_add_region(e820x, start, size, new_type); + __e820_add_region(e820x, end, ei_end - end, ei->type); + ei->size = start - ei->addr; + real_updated_size += size; + continue; + } + /* partially covered */ final_start = max(start, ei->addr); - final_end = min(start + size, ei->addr + ei->size); + final_end = min(end, ei_end); if (final_start >= final_end) continue;