From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: automatic memory ballooning? Date: Mon, 17 Aug 2009 15:46:46 +0300 Message-ID: <4A895136.1060300@redhat.com> References: <200908160355.46652.tfjellstrom@shaw.ca> <200908170449.40945.tfjellstrom@shaw.ca> <4A894070.9080402@redhat.com> <200908170632.11428.tfjellstrom@shaw.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org, dlaor@redhat.com To: tfjellstrom@shaw.ca Return-path: Received: from mx2.redhat.com ([66.187.237.31]:34634 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753829AbZHQMqs (ORCPT ); Mon, 17 Aug 2009 08:46:48 -0400 In-Reply-To: <200908170632.11428.tfjellstrom@shaw.ca> Sender: kvm-owner@vger.kernel.org List-ID: On 08/17/2009 03:32 PM, Thomas Fjellstrom wrote: > On Mon August 17 2009, Avi Kivity wrote: > >> On 08/17/2009 01:49 PM, Thomas Fjellstrom wrote: >> >>> One thing I found odd about kvm's ballooning is that it actually seems to >>> change how much ram the guest has. I really didn't expect "free -m" to >>> report that the guest only had 64M ram after I manually ballooned the >>> ram. I was however expecting it just to free ram it wasn't using in the >>> host. To me, it just doesn't seem to be the same thing. now it'll start >>> swapping at 64M ram instead of just reallocating the ram it used to have. >>> >> You expectations aren't realistic. kvm never allocates the ram the >> guest doesn't use in the first place. >> > Really? So htop is lying to me then? Of course not. > I gave 1G ram to a kvm linux guest using > virtio (disk, net, ballooning), and RES clearly said 1G, and VIRT actually > said somewhere around 1.3 to 1.6G. It stayed that way for over a day, and the > guest did nothing the entire time. > VIRT size is pointless, it includes tons of shared libraries which don't really affect memory usage. Try cat /proc/$pid/maps (or pmap $pid) on a qemu instance and see. -- error compiling committee.c: too many arguments to function