From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756776Ab2IJB4K (ORCPT ); Sun, 9 Sep 2012 21:56:10 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:19495 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1756700Ab2IJB4C (ORCPT ); Sun, 9 Sep 2012 21:56:02 -0400 X-IronPort-AV: E=Sophos;i="4.80,396,1344182400"; d="scan'208";a="5810196" Message-ID: <504D4A08.7090602@cn.fujitsu.com> Date: Mon, 10 Sep 2012 10:01:44 +0800 From: Wen Congyang User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.9) Gecko/20100413 Fedora/3.0.4-2.fc13 Thunderbird/3.0.4 MIME-Version: 1.0 To: Yasuaki Ishimatsu CC: Andrew Morton , x86@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-acpi@vger.kernel.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, linux-ia64@vger.kernel.org, cmetcalf@tilera.com, sparclinux@vger.kernel.org, rientjes@google.com, liuj97@gmail.com, len.brown@intel.com, benh@kernel.crashing.org, paulus@samba.org, cl@linux.com, minchan.kim@gmail.com, kosaki.motohiro@jp.fujitsu.com Subject: Re: [RFC v8 PATCH 00/20] memory-hotplug: hot-remove physical memory References: <1346148027-24468-1-git-send-email-wency@cn.fujitsu.com> <20120831134956.fec0f681.akpm@linux-foundation.org> <504D467D.2080201@jp.fujitsu.com> In-Reply-To: <504D467D.2080201@jp.fujitsu.com> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/09/10 09:55:29, Serialize by Router on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/09/10 09:55:30, Serialize complete at 2012/09/10 09:55:30 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org At 09/10/2012 09:46 AM, Yasuaki Ishimatsu Wrote: > Hi Wen, > > 2012/09/01 5:49, Andrew Morton wrote: >> On Tue, 28 Aug 2012 18:00:07 +0800 >> wency@cn.fujitsu.com wrote: >> >>> This patch series aims to support physical memory hot-remove. >> >> Have you had much review and testing feedback yet? >> >>> The patches can free/remove the following things: >>> >>> - acpi_memory_info : [RFC PATCH 4/19] >>> - /sys/firmware/memmap/X/{end, start, type} : [RFC PATCH 8/19] >>> - iomem_resource : [RFC PATCH 9/19] >>> - mem_section and related sysfs files : [RFC PATCH 10-11, >>> 13-16/19] >>> - page table of removed memory : [RFC PATCH 12/19] >>> - node and related sysfs files : [RFC PATCH 18-19/19] >>> >>> If you find lack of function for physical memory hot-remove, please >>> let me >>> know. >> > >> I doubt if many people have hardware which permits physical memory >> removal? How would you suggest that people with regular hardware can >> test these chagnes? > > How do you test the patch? As Andrew says, for hot-removing memory, > we need a particular hardware. I think so too. So many people may want > to know how to test the patch. > If we apply following patch to kvm guest, can we hot-remove memory on > kvm guest? > > http://lists.gnu.org/archive/html/qemu-devel/2012-07/msg01389.html Yes, if we apply this patchset, we can test hot-remove memory on kvm guest. But that patchset doesn't implement _PS3, so there is some restriction. Thanks Wen Congyang > > Thanks, > Yasuaki Ishimatsu > >> >>> Known problems: >>> 1. memory can't be offlined when CONFIG_MEMCG is selected. >> >> That's quite a problem! Do you have a description of why this is the >> case, and a plan for fixing it? >> > > >