Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760976AbaGRJRq (ORCPT ); Fri, 18 Jul 2014 05:17:46 -0400 Received: from cn.fujitsu.com ([59.151.112.132]:50410 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1755451AbaGRJRn (ORCPT ); Fri, 18 Jul 2014 05:17:43 -0400 X-IronPort-AV: E=Sophos;i="5.00,914,1396972800"; d="scan'208";a="33451710" Message-ID: <53C8E602.1060301@cn.fujitsu.com> Date: Fri, 18 Jul 2014 17:16:50 +0800 From: Zhang Yanfei User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20131030 Thunderbird/17.0.10 MIME-Version: 1.0 To: Wang Nan CC: Ingo Molnar , Yinghai Lu , Mel Gorman , Andrew Morton , Pei Feiyue , , , , , , Subject: Re: [PATCH 0/5] memory-hotplug: suitable memory should go to ZONE_MOVABLE References: <1405670163-53747-1-git-send-email-wangnan0@huawei.com> In-Reply-To: <1405670163-53747-1-git-send-email-wangnan0@huawei.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.167.225.89] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On 07/18/2014 03:55 PM, Wang Nan wrote: > This series of patches fix a problem when adding memory in bad manner. > For example: for a x86_64 machine booted with "mem=400M" and with 2GiB > memory installed, following commands cause problem: > > # echo 0x40000000 > /sys/devices/system/memory/probe > [ 28.613895] init_memory_mapping: [mem 0x40000000-0x47ffffff] > # echo 0x48000000 > /sys/devices/system/memory/probe > [ 28.693675] init_memory_mapping: [mem 0x48000000-0x4fffffff] > # echo online_movable > /sys/devices/system/memory/memory9/state > # echo 0x50000000 > /sys/devices/system/memory/probe > [ 29.084090] init_memory_mapping: [mem 0x50000000-0x57ffffff] > # echo 0x58000000 > /sys/devices/system/memory/probe > [ 29.151880] init_memory_mapping: [mem 0x58000000-0x5fffffff] > # echo online_movable > /sys/devices/system/memory/memory11/state > # echo online> /sys/devices/system/memory/memory8/state > # echo online> /sys/devices/system/memory/memory10/state > # echo offline> /sys/devices/system/memory/memory9/state > [ 30.558819] Offlined Pages 32768 > # free > total used free shared buffers cached > Mem: 780588 18014398509432020 830552 0 0 51180 > -/+ buffers/cache: 18014398509380840 881732 > Swap: 0 0 0 > > This is because the above commands probe higher memory after online a > section with online_movable, which causes ZONE_HIGHMEM (or ZONE_NORMAL > for systems without ZONE_HIGHMEM) overlaps ZONE_MOVABLE. Yeah, this is rare in reality but can happen. Could you please also include the free result and zoneinfo after applying your patch? Thanks. > > After the second online_movable, the problem can be observed from > zoneinfo: > > # cat /proc/zoneinfo > ... > Node 0, zone Movable > pages free 65491 > min 250 > low 312 > high 375 > scanned 0 > spanned 18446744073709518848 > present 65536 > managed 65536 > ... > > This series of patches solve the problem by checking ZONE_MOVABLE when > choosing zone for new memory. If new memory is inside or higher than > ZONE_MOVABLE, makes it go there instead. > > > Wang Nan (5): > memory-hotplug: x86_64: suitable memory should go to ZONE_MOVABLE > memory-hotplug: x86_32: suitable memory should go to ZONE_MOVABLE > memory-hotplug: ia64: suitable memory should go to ZONE_MOVABLE > memory-hotplug: sh: suitable memory should go to ZONE_MOVABLE > memory-hotplug: powerpc: suitable memory should go to ZONE_MOVABLE > > arch/ia64/mm/init.c | 7 +++++++ > arch/powerpc/mm/mem.c | 6 ++++++ > arch/sh/mm/init.c | 13 ++++++++----- > arch/x86/mm/init_32.c | 6 ++++++ > arch/x86/mm/init_64.c | 10 ++++++++-- > 5 files changed, 35 insertions(+), 7 deletions(-) > -- Thanks. Zhang Yanfei -- 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/