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=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,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 450BCCA9EB9 for ; Tue, 22 Oct 2019 08:15:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1993721BE5 for ; Tue, 22 Oct 2019 08:15:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="CGUi+bZ+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388280AbfJVIPT (ORCPT ); Tue, 22 Oct 2019 04:15:19 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:42640 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2388061AbfJVIPT (ORCPT ); Tue, 22 Oct 2019 04:15:19 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1571732117; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=8AwgANZ9oDz6D4lqOk6X+wOo3w6oZWgeLO/Mbb7W20g=; b=CGUi+bZ+lYOUEzURb/nyM5w0RJ6OGF3sw3EKBu9ZiWGLGnm6NADY274NzG9xjT87gp7h2a mGHRqmIhLdAquq9PoB+OiMwfkBiNhnVd8PKoEjyLoEQBcRICRtRuciOKD1j3WxPL/9/LAX DUSLKI/oQfy8l8WAUPpfS95kgjMZPpk= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-220-TBXAxhgSMVScSIvfMbhVQQ-1; Tue, 22 Oct 2019 04:15:14 -0400 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 79DEB1800D6A; Tue, 22 Oct 2019 08:15:11 +0000 (UTC) Received: from [10.36.117.11] (ovpn-117-11.ams2.redhat.com [10.36.117.11]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2065819C4F; Tue, 22 Oct 2019 08:15:07 +0000 (UTC) Subject: Re: [PATCH v2 0/2] mm: Memory offlining + page isolation cleanups To: Michal Hocko 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 References: <20191021172353.3056-1-david@redhat.com> <25d3f071-3268-298b-e0c8-9c307d1015fe@redhat.com> <20191022080835.GZ9379@dhcp22.suse.cz> From: David Hildenbrand Organization: Red Hat GmbH Message-ID: <1f56744d-2c22-6c12-8fe8-4a71e791c467@redhat.com> Date: Tue, 22 Oct 2019 10:15:07 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.1.1 MIME-Version: 1.0 In-Reply-To: <20191022080835.GZ9379@dhcp22.suse.cz> Content-Language: en-US X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-MC-Unique: TBXAxhgSMVScSIvfMbhVQQ-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 22.10.19 10:08, Michal Hocko wrote: > On Tue 22-10-19 08:52:28, David Hildenbrand wrote: >> On 21.10.19 19:23, David Hildenbrand wrote: >>> Two cleanups that popped up while working on (and discussing) virtio-me= m: >>> https://lkml.org/lkml/2019/9/19/463 >>> >>> Tested with DIMMs on x86. >>> >>> As discussed with michal in v1, I'll soon look into removing the use >>> of PG_reserved during memory onlining completely - most probably >>> disallowing to offline memory blocks with holes, cleaning up the >>> onlining+offlining code. >> >> BTW, I remember that ZONE_DEVICE pages are still required to be set >> PG_reserved. That has to be sorted out first. >=20 > Do they? Yes, especially KVM code :/ >=20 >> I remember that somebody was >> working on it a while ago but didn't hear about that again. Will look in= to >> that as well - should be as easy as adding a zone check (if there isn't = a >> pfn_to_online_page() check already). But of course, there might be speci= al >> cases .... >=20 > I remember Alexander didn't want to change the PageReserved handling > because he was worried about unforeseeable side effects. I have a vague > recollection he (or maybe Dan) has promissed some follow up clean ups > which didn't seem to materialize. I'm looking into it right now, especially the KVM part. --=20 Thanks, David / dhildenb