From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f44.google.com (mail-wm0-f44.google.com [74.125.82.44]) by kanga.kvack.org (Postfix) with ESMTP id A49D36B0038 for ; Tue, 15 Dec 2015 22:28:07 -0500 (EST) Received: by mail-wm0-f44.google.com with SMTP id n186so53024813wmn.0 for ; Tue, 15 Dec 2015 19:28:07 -0800 (PST) Received: from szxga02-in.huawei.com (szxga02-in.huawei.com. [119.145.14.65]) by mx.google.com with ESMTPS id iq7si6681021wjb.143.2015.12.15.19.28.03 for (version=TLS1 cipher=AES128-SHA bits=128/128); Tue, 15 Dec 2015 19:28:06 -0800 (PST) Message-ID: <5670D83E.9040407@huawei.com> Date: Wed, 16 Dec 2015 11:19:26 +0800 From: Xishi Qiu MIME-Version: 1.0 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 Sender: owner-linux-mm@kvack.org List-ID: To: Vitaly Kuznetsov Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, 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 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 -- 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