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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 E9479CA9EB9 for ; Tue, 22 Oct 2019 09:14:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C0449207FC for ; Tue, 22 Oct 2019 09:14:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1571735675; bh=xH0PBkt/EYM2XeUpTwcTDiKlAVw0oDtSEMxnc7Ve8fA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=12j1Ge47l73uMrdukYKZhgJkgiAqwwdkfZLl5he7MeTbDgao2HDLIHqrVjsxuvY4v kmmC0ZPYWHMml7g/r4/8CotDHHQUmjePKwnjWuK+boX4sUp2VLY0iLhxB3I5GgRFdd MwobsI/W6zXtGi/kg35jbyDfJJ9DPs9RMU1NesBA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388239AbfJVJOe (ORCPT ); Tue, 22 Oct 2019 05:14:34 -0400 Received: from mx2.suse.de ([195.135.220.15]:41958 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1731314AbfJVJOe (ORCPT ); Tue, 22 Oct 2019 05:14:34 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 360B2B954; Tue, 22 Oct 2019 09:14:32 +0000 (UTC) Date: Tue, 22 Oct 2019 11:14:31 +0200 From: Michal Hocko To: David Hildenbrand Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Alexander Duyck , Andrew Morton , Anshuman Khandual , Dan Williams , Mel Gorman , Mike Rapoport , Mike Rapoport , Oscar Salvador , Pavel Tatashin , Pavel Tatashin , Pingfan Liu , Qian Cai , Vlastimil Babka , Wei Yang Subject: Re: [PATCH v2 0/2] mm: Memory offlining + page isolation cleanups Message-ID: <20191022091431.GG9379@dhcp22.suse.cz> References: <20191021172353.3056-1-david@redhat.com> <25d3f071-3268-298b-e0c8-9c307d1015fe@redhat.com> <20191022080835.GZ9379@dhcp22.suse.cz> <1f56744d-2c22-6c12-8fe8-4a71e791c467@redhat.com> <20191022082131.GC9379@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue 22-10-19 10:32:11, David Hildenbrand wrote: [...] > E.g., arch/x86/kvm/mmu.c:kvm_is_mmio_pfn() Thanks for these references. I am not really familiar with kvm so I cannot really comment on the specific code but I am wondering why it simply doesn't check for ZONE_DEVICE explicitly? Also we do care about holes in RAM (from the early boot), those should be reserved already AFAIR. So we are left with hotplugged memory with holes and I am not really sure we should bother with this until there is a clear usecase in sight. -- Michal Hocko SUSE Labs