From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754760Ab2DIQ4P (ORCPT ); Mon, 9 Apr 2012 12:56:15 -0400 Received: from nat28.tlf.novell.com ([130.57.49.28]:36957 "EHLO nat28.tlf.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753142Ab2DIQ4N convert rfc822-to-8bit (ORCPT ); Mon, 9 Apr 2012 12:56:13 -0400 Message-Id: <4F8322BB020000780008229D@nat28.tlf.novell.com> X-Mailer: Novell GroupWise Internet Agent 12.0.0 Date: Mon, 09 Apr 2012 17:56:11 +0100 From: "Jan Beulich" To: , Cc: , Subject: Re: [Xen-devel] [PATCH 6/7] xen/setup: Make dom0_mem=XGB behavior be similar to classic Xen kernels. References: <1333139850-28456-1-git-send-email-konrad.wilk@oracle.com> <1333139850-28456-7-git-send-email-konrad.wilk@oracle.com> <4F7ABBC4.4050106@citrix.com> <20120406205909.GA26309@phenom.dumpdata.com> In-Reply-To: <20120406205909.GA26309@phenom.dumpdata.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8BIT Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >>> Konrad Rzeszutek Wilk 04/06/12 11:04 PM >>> >> With your new behaviour it will no longer possible to specify an >> unlimited balloon but a limited number of initial pages. This is >> behaviour that Jan said he used. > >I am not sure I see the problem - I mean if one uses: > >dom0_mem=min:8G,max:16G > >I understand that we want to start at 8GB and if the user >choose to - balloon up to 16GB. > >But doing this: > >dom0_mem=8G > >and allocating pagetables up to .. say 32GB, seems counter-intuive >as the effect is similar to having no 'dom0_mem' except that the initial >size is smaller. What's counter intuitive here? There may not be a need - from the perspective of the kernel - for a hard upper limit enforced by Xen (i.e. the pseudo infinity we have right now may be quite fine). Anyway, as said in the other reply already - unless this is to address a bug, I don't see the point in changing behavior that has been that way for a pretty long time. Jan