From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35333) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z7NNO-0007gQ-2P for qemu-devel@nongnu.org; Tue, 23 Jun 2015 08:32:30 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Z7NNK-0002Iz-TV for qemu-devel@nongnu.org; Tue, 23 Jun 2015 08:32:30 -0400 Received: from mail.iv.net.pl ([195.191.233.10]:33289) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z7NNK-0002I2-40 for qemu-devel@nongnu.org; Tue, 23 Jun 2015 08:32:26 -0400 References: CABYiri9GzWLrqmQXphoKziS3pdGF+vRcGAo=ibv5k9sE_8QurA@mail.gmail.com From: Piotr Rybicki Message-ID: <558951D4.1010603@innervision.pl> Date: Tue, 23 Jun 2015 14:32:20 +0200 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] incorrect memory size inside vm List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: andrey@xdel.ru Cc: qemu-devel@nongnu.org > Thanks Piotr, the lack of the host-side memory shrinkage after balloon > deflation is interesting anyway, hopefully you may share guest` dmesg > bits from compiled-in balloon to check visible signs of the issue It is really hard to see dmesg output via vnc console, when kernel is sending so many messages looped :( > (balloon should be initialized *before* DIMMs are being onlined, so > the behavior of the balloon itself it not clear at least for me). Why balloon should be initialized before DIMMs onlined? DIMMS are onlined as soon as udev starts (i have udev rule to online mem, cpu), so system has to start init process. I don't see any option to online DIMMs before booting reaches init process. With balloon compiled-in, it starts to shrink memmory (for example to shrink 8GB, when 1GB 'base' mem is defined, and 10GB in DIMMs), when there is only 1GB 'base' memory. This leads to problem With balloon loaded as a module, shrinking starts after init has begun (because system has to at least mount filesystem where balloon module is placed to load) Well, i can't proove this with dmesg, but with balloon as module - system is booting and working as expected. With balloon compiled-in - system does not boot saying there is no free mem for balloon to shrink it. Best regards Piotr Rybicki