From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750775AbWEQQI0 (ORCPT ); Wed, 17 May 2006 12:08:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750789AbWEQQI0 (ORCPT ); Wed, 17 May 2006 12:08:26 -0400 Received: from mx1.redhat.com ([66.187.233.31]:29603 "EHLO mx1.redhat.com") by vger.kernel.org with ESMTP id S1750775AbWEQQI0 (ORCPT ); Wed, 17 May 2006 12:08:26 -0400 Date: Wed, 17 May 2006 09:06:45 -0700 From: Pete Zaitcev To: Chris Wright Cc: linux-kernel@vger.kernel.org, virtualization@lists.osdl.org, Christian.Limpach@cl.cam.ac.uk, xen-devel@lists.xensource.com, ian.pratt@xensource.com, zaitcev@redhat.com Subject: Re: [RFC PATCH 08/35] Add Xen-specific memory management definitions Message-Id: <20060517090645.0b72bd2d.zaitcev@redhat.com> In-Reply-To: <20060509085151.047254000@sous-sol.org> References: <20060509084945.373541000@sous-sol.org> <20060509085151.047254000@sous-sol.org> Organization: Red Hat, Inc. X-Mailer: Sylpheed version 2.2.3 (GTK+ 2.8.17; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 09 May 2006 00:00:08 -0700, Chris Wright wrote: > +static inline unsigned long pfn_to_mfn(unsigned long pfn) > +{ > +#ifndef CONFIG_XEN_SHADOW_MODE > + if (xen_feature(XENFEAT_auto_translated_physmap)) > + return pfn; > + return phys_to_machine_mapping[(unsigned int)(pfn)] & > + ~FOREIGN_FRAME_BIT; > +#else > + return pfn; > +#endif > +} Why do we need several modes in Linux guests? If a significant tradeoff exists (for example, between performance and maximum addressable memory), then we need to think about the real issue instead of throwing config options into the pot. -- Pete