From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx201.postini.com [74.125.245.201]) by kanga.kvack.org (Postfix) with SMTP id 1D1646B0031 for ; Thu, 5 Sep 2013 23:10:27 -0400 (EDT) Message-ID: <52294758.7030801@cn.fujitsu.com> Date: Fri, 06 Sep 2013 11:09:12 +0800 From: Tang Chen MIME-Version: 1.0 Subject: Re: [PATCH 10/11] x86, mem-hotplug: Support initialize page tables from low to high. References: <1377596268-31552-1-git-send-email-tangchen@cn.fujitsu.com> <1377596268-31552-11-git-send-email-tangchen@cn.fujitsu.com> <20130905133027.GA23038@hacker.(null)> <52293118.8080707@cn.fujitsu.com> <20130906021653.GA1062@hacker.(null)> In-Reply-To: <20130906021653.GA1062@hacker.(null)> Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=ISO-8859-1; format=flowed Sender: owner-linux-mm@kvack.org List-ID: To: Wanpeng Li Cc: rjw@sisk.pl, lenb@kernel.org, tglx@linutronix.de, mingo@elte.hu, hpa@zytor.com, akpm@linux-foundation.org, tj@kernel.org, trenn@suse.de, yinghai@kernel.org, jiang.liu@huawei.com, wency@cn.fujitsu.com, laijs@cn.fujitsu.com, isimatu.yasuaki@jp.fujitsu.com, izumi.taku@jp.fujitsu.com, mgorman@suse.de, minchan@kernel.org, mina86@mina86.com, gong.chen@linux.intel.com, vasilis.liaskovitis@profitbricks.com, lwoodman@redhat.com, riel@redhat.com, jweiner@redhat.com, prarit@redhat.com, zhangyanfei@cn.fujitsu.com, x86@kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-acpi@vger.kernel.org Hi Wanpeng, On 09/06/2013 10:16 AM, Wanpeng Li wrote: ...... >>>> +#ifdef CONFIG_MOVABLE_NODE >>>> + unsigned long kernel_end; >>>> + >>>> + if (movablenode_enable_srat&& >>>> + memblock.current_order == MEMBLOCK_ORDER_LOW_TO_HIGH) { >>> >>> I think memblock.current_order == MEMBLOCK_ORDER_LOW_TO_HIGH is always >>> true if config MOVABLE_NODE and movablenode_enable_srat == true if PATCH >>> 11/11 is applied. >> >> memblock.current_order == MEMBLOCK_ORDER_LOW_TO_HIGH is true here if >> MOVABLE_NODE >> is configured, and it will be reset after SRAT is parsed. But >> movablenode_enable_srat >> could only be true when users specify movablenode boot option in the >> kernel commandline. > > You are right. > > I mean the change should be: > > +#ifdef CONFIG_MOVABLE_NODE > + unsigned long kernel_end; > + > + if (movablenode_enable_srat) { > > The is unnecessary to check memblock.current_order since it is always true > if movable_node is configured and movablenode_enable_srat is true. > But I think, memblock.current_order is set outside init_mem_mapping(). And the path in the if statement could only be run when current order is from low to high. So I think it is safe to check it here. I prefer to keep it at least in the next version patch-set. If others also think it is unnecessary, I'm OK with removing the checking. :) Thanks. :) -- 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