From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965710AbbLPD2N (ORCPT ); Tue, 15 Dec 2015 22:28:13 -0500 Received: from szxga02-in.huawei.com ([119.145.14.65]:30926 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933916AbbLPD2L (ORCPT ); Tue, 15 Dec 2015 22:28:11 -0500 Message-ID: <5670D83E.9040407@huawei.com> Date: Wed, 16 Dec 2015 11:19:26 +0800 From: Xishi Qiu User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:12.0) Gecko/20120428 Thunderbird/12.0.1 MIME-Version: 1.0 To: Vitaly Kuznetsov CC: , , , Jonathan Corbet , "Greg Kroah-Hartman" , Daniel Kiper , Dan Williams , Tang Chen , David Vrabel , "David Rientjes" , Andrew Morton , Naoya Horiguchi , Gu Zheng , Mel Gorman , "K. Y. Srinivasan" , yanxiaofeng , Changsheng Liu Subject: Re: [PATCH RFC] memory-hotplug: add automatic onlining policy for the newly added memory References: <1450202753-5556-1-git-send-email-vkuznets@redhat.com> In-Reply-To: <1450202753-5556-1-git-send-email-vkuznets@redhat.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.25.179] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020202.5670D84C.014B,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2013-06-18 04:22:30, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 90dddc4c0bccef5934d2d54a30e1dd94 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2015/12/16 2:05, Vitaly Kuznetsov wrote: > Currently, all newly added memory blocks remain in 'offline' state unless > someone onlines them, some linux distributions carry special udev rules > like: > > SUBSYSTEM=="memory", ACTION=="add", ATTR{state}=="offline", ATTR{state}="online" > > to make this happen automatically. This is not a great solution for virtual > machines where memory hotplug is being used to address high memory pressure > situations as such onlining is slow and a userspace process doing this > (udev) has a chance of being killed by the OOM killer as it will probably > require to allocate some memory. > > Introduce default policy for the newly added memory blocks in > /sys/devices/system/memory/hotplug_autoonline file with two possible > values: "offline" (the default) which preserves the current behavior and > "online" which causes all newly added memory blocks to go online as > soon as they're added. > > Cc: Jonathan Corbet > Cc: Greg Kroah-Hartman > Cc: Daniel Kiper > Cc: Dan Williams > Cc: Tang Chen > Cc: David Vrabel > Cc: David Rientjes > Cc: Andrew Morton > Cc: Naoya Horiguchi > Cc: Gu Zheng > Cc: Xishi Qiu > Cc: Mel Gorman > Cc: "K. Y. Srinivasan" > Signed-off-by: Vitaly Kuznetsov > --- > - I was able to find previous attempts to fix the issue, e.g.: > http://marc.info/?l=linux-kernel&m=137425951924598&w=2 > http://marc.info/?l=linux-acpi&m=127186488905382 > but I'm not completely sure why it didn't work out and the solution > I suggest is not 'smart enough', thus 'RFC'. + CC: yanxiaofeng@inspur.com liuchangsheng@inspur.com Hi Vitaly, Why not use udev rule? I think it can online pages automatically. Thanks, Xishi Qiu