From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f45.google.com (mail-pa0-f45.google.com [209.85.220.45]) by kanga.kvack.org (Postfix) with ESMTP id 2F8DB6B0254 for ; Wed, 26 Aug 2015 03:20:55 -0400 (EDT) Received: by pabzx8 with SMTP id zx8so60931547pab.1 for ; Wed, 26 Aug 2015 00:20:54 -0700 (PDT) Received: from heian.cn.fujitsu.com ([59.151.112.132]) by mx.google.com with ESMTP id w7si37030482pbt.197.2015.08.26.00.20.53 for ; Wed, 26 Aug 2015 00:20:54 -0700 (PDT) Message-ID: <55DD6877.6080709@cn.fujitsu.com> Date: Wed, 26 Aug 2015 15:19:19 +0800 From: Tang Chen MIME-Version: 1.0 Subject: Re: [PATCH 2/2] memory-hotplug: remove reset_node_managed_pages() and reset_node_managed_pages() in hotadd_new_pgdat() References: <55C9A3A9.5090300@huawei.com> <55C9A554.4090509@huawei.com> <55D9A036.7060506@cn.fujitsu.com> <55DAE113.20503@huawei.com> <55DAE666.5020302@cn.fujitsu.com> <55DAFEEB.4050601@huawei.com> In-Reply-To: <55DAFEEB.4050601@huawei.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Xishi Qiu Cc: Andrew Morton , Yasuaki Ishimatsu , Kamezawa Hiroyuki , izumi.taku@jp.fujitsu.com, Linux MM , LKML , Yasuaki Ishimatsu On 08/24/2015 07:24 PM, Xishi Qiu wrote: > ...... >>>> [ 2007.584000] On node 5 totalpages: 0 >>>> [ 2007.585000] Built 5 zonelists in Node order, mobility grouping on. Total pages: 32588823 >>>> [ 2007.594000] Policy zone: Normal >>>> [ 2007.598000] init_memory_mapping: [mem 0x60000000000-0x607ffffffff] >>>> >>>> >>>> And also, if we merge this patch, /sys/devices/system/node/nodeX/meminfo will break. >>>> >>> trigger call trace? >> No. There is no error output. But if you see /sys/devices/system/node/nodeX/meminfo, >> memory size will double because totalpages is calculated once here, and one more time >> when onlining memory. >> > Hi Tang, > > Do you mean si_meminfo_node() -> val->totalram = managed_pages; will be added double? > But my patch will keep it 0 in hotadd_new_pgdat(), so it will not be double, right? > Hi, I mean this: online_pages() |--> zone->zone_pgdat->node_present_pages += onlined_pages; It will be double. Since meminfo data is retrieved from these kernel structures, /proc/meminfo will be broken. Actually speaking, reset it when hot-adding memory is not a good idea. We should make the memory init code be suitable for both boot code and memory hot-plug code. 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