From mboxrd@z Thu Jan 1 00:00:00 1970 From: Luiz Capitulino Subject: Re: [BUG] Balloon malfunctions with memory hotplug Date: Mon, 2 Mar 2015 14:04:54 -0500 Message-ID: <20150302140454.70a2006b@redhat.com> References: <20150226142629.749f4f1f@redhat.com> <54EFEDF0.10803@huawei.com> <20150302062234.GG26196@grmbl.mre> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: zhanghailiang , qemu-devel@nongnu.org, hangaohuai@huawei.com, peter.huangpeng@huawei.com, kvm@vger.kernel.org, imammedo@redhat.com, pkrempa@redhat.com, eblake@redhat.com, mst@redhat.com To: Amit Shah Return-path: Received: from mx1.redhat.com ([209.132.183.28]:33341 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754148AbbCBTFE (ORCPT ); Mon, 2 Mar 2015 14:05:04 -0500 In-Reply-To: <20150302062234.GG26196@grmbl.mre> Sender: kvm-owner@vger.kernel.org List-ID: On Mon, 2 Mar 2015 11:52:34 +0530 Amit Shah wrote: > > >Another important detail is that, I *suspect* that a very similar > > >bug already exists with 32-bit guests even without memory > > >hotplug: what happens if you assign 6GB to a 32-bit without PAE > > >support? I think the same problem we're seeing with memory > > >hotplug will happen and solution 1 won't fix this, although > > >no one seems to care about 32-bit guests... > > Not just 32-bit guests; even 64-bit guests restricted with mem= on the > cmdline. You're right. So, it's an already existing issue that becomes very apparent with memory hotplug. > I know we've discussed this in the past, and I recall > virtio-balloon v2 was going to address this all; sadly I've not kept > uptodate with it. Me neither :( From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59246) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YSVeK-0005zg-P6 for qemu-devel@nongnu.org; Mon, 02 Mar 2015 14:05:05 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YSVeJ-0003cJ-Vh for qemu-devel@nongnu.org; Mon, 02 Mar 2015 14:05:04 -0500 Received: from mx1.redhat.com ([209.132.183.28]:56488) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YSVeJ-0003aF-Oo for qemu-devel@nongnu.org; Mon, 02 Mar 2015 14:05:03 -0500 Date: Mon, 2 Mar 2015 14:04:54 -0500 From: Luiz Capitulino Message-ID: <20150302140454.70a2006b@redhat.com> In-Reply-To: <20150302062234.GG26196@grmbl.mre> References: <20150226142629.749f4f1f@redhat.com> <54EFEDF0.10803@huawei.com> <20150302062234.GG26196@grmbl.mre> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [BUG] Balloon malfunctions with memory hotplug List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Amit Shah Cc: hangaohuai@huawei.com, pkrempa@redhat.com, zhanghailiang , kvm@vger.kernel.org, mst@redhat.com, peter.huangpeng@huawei.com, qemu-devel@nongnu.org, imammedo@redhat.com On Mon, 2 Mar 2015 11:52:34 +0530 Amit Shah wrote: > > >Another important detail is that, I *suspect* that a very similar > > >bug already exists with 32-bit guests even without memory > > >hotplug: what happens if you assign 6GB to a 32-bit without PAE > > >support? I think the same problem we're seeing with memory > > >hotplug will happen and solution 1 won't fix this, although > > >no one seems to care about 32-bit guests... > > Not just 32-bit guests; even 64-bit guests restricted with mem= on the > cmdline. You're right. So, it's an already existing issue that becomes very apparent with memory hotplug. > I know we've discussed this in the past, and I recall > virtio-balloon v2 was going to address this all; sadly I've not kept > uptodate with it. Me neither :(