From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F1B7BC433DF for ; Thu, 13 Aug 2020 07:33:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AFE242078B for ; Thu, 13 Aug 2020 07:33:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="ewJyWfwn" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726623AbgHMHdp (ORCPT ); Thu, 13 Aug 2020 03:33:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34778 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726048AbgHMHdo (ORCPT ); Thu, 13 Aug 2020 03:33:44 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A2EE3C061757 for ; Thu, 13 Aug 2020 00:33:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=n009f/kUZMBxeE9pa5fT61XhvAWtOw5mBgdxS83PReo=; b=ewJyWfwnC0ik8H5uYBiEUgc8qw K63WWJCeQW4URaGKnP3bJMPhOeNmCl2r9HBvMuBF5dnPSDi8IguASNmb9WnUMfX35v7tUdKgFGFCW Dtj3+9pGtaUNV1A0c9hR3AuKvEvmwPsTGz7CdUiiK72F1NKLNVYLne0AFgg3IxB84iFmDaBPPqdCN 98A2cAaqK05f0BcTc/VKFvGqXMkJDnpSnL0u8/j7l7/KKtWqcE/WeKXf9jtab+8IXs8AoM2QX86Rw M7XZhcIHa7215LpMf+9bwNqMSJV4NC2heYZc0INb8N2zFJgS3OXmU9ZX71SIlSr+dz2hYCatmYO7x NvJ0/4jQ==; Received: from hch by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1k67k1-0004FT-VS; Thu, 13 Aug 2020 07:33:38 +0000 Date: Thu, 13 Aug 2020 08:33:37 +0100 From: Christoph Hellwig To: Roger Pau Monne Cc: linux-kernel@vger.kernel.org, Oleksandr Andrushchenko , David Airlie , Daniel Vetter , Boris Ostrovsky , Juergen Gross , Stefano Stabellini , Dan Carpenter , Wei Liu , Yan Yankovskyi , dri-devel@lists.freedesktop.org, xen-devel@lists.xenproject.org, linux-mm@kvack.org, David Hildenbrand , Michal Hocko , Dan Williams Subject: Re: [PATCH v4 2/2] xen: add helpers to allocate unpopulated memory Message-ID: <20200813073337.GA16160@infradead.org> References: <20200811094447.31208-1-roger.pau@citrix.com> <20200811094447.31208-3-roger.pau@citrix.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200811094447.31208-3-roger.pau@citrix.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Aug 11, 2020 at 11:44:47AM +0200, Roger Pau Monne wrote: > If enabled (because ZONE_DEVICE is supported) the usage of the new > functionality untangles Xen balloon and RAM hotplug from the usage of > unpopulated physical memory ranges to map foreign pages, which is the > correct thing to do in order to avoid mappings of foreign pages depend > on memory hotplug. So please just select ZONE_DEVICE if this is so much better rather than maintaining two variants.