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=-0.9 required=3.0 tests=FROM_EXCESS_BASE64, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 CC17DC43441 for ; Mon, 26 Nov 2018 14:22:44 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 2F6E920855 for ; Mon, 26 Nov 2018 14:22:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2F6E920855 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 433Tdt1VpmzDqHH for ; Tue, 27 Nov 2018 01:22:42 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: lists.ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=suse.de (client-ip=195.135.220.15; helo=mx1.suse.de; envelope-from=msuchanek@suse.de; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=suse.de Received: from mx1.suse.de (mx2.suse.de [195.135.220.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 433TbH3mj5zDqNS for ; Tue, 27 Nov 2018 01:20:26 +1100 (AEDT) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id C7B4FB02B; Mon, 26 Nov 2018 14:20:22 +0000 (UTC) Date: Mon, 26 Nov 2018 15:20:15 +0100 From: Michal =?UTF-8?B?U3VjaMOhbmVr?= To: David Hildenbrand Subject: Re: [PATCH RFC] mm/memory_hotplug: Introduce memory block types Message-ID: <20181126152015.7464c786@naga> In-Reply-To: References: <20180928150357.12942-1-david@redhat.com> <20181123190653.6da91461@kitsune.suse.cz> X-Mailer: Claws Mail 3.17.1 (GTK+ 2.24.32; x86_64-suse-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kate Stewart , Rich Felker , linux-ia64@vger.kernel.org, linux-sh@vger.kernel.org, Peter Zijlstra , Dave Hansen , Heiko Carstens , linux-mm@kvack.org, Michal Hocko , Paul Mackerras , "H. Peter Anvin" , Rashmica Gupta , "K. Y. Srinivasan" , Boris Ostrovsky , Stephen Rothwell , Michael Neuling , Stephen Hemminger , Yoshinori Sato , linux-acpi@vger.kernel.org, Ingo Molnar , xen-devel@lists.xenproject.org, Rob Herring , Len Brown , Pavel Tatashin , linux-s390@vger.kernel.org, "mike.travis@hpe.com" , Haiyang Zhang , Jonathan =?UTF-8?B?TmV1c2Now6Rm?= =?UTF-8?B?ZXI=?= , Nicholas Piggin , Joe Perches , =?UTF-8?B?SsOpcsO0bWU=?= Glisse , Mike Rapoport , Borislav Petkov , Andy Lutomirski , Dan Williams , Joonsoo Kim , Oscar Salvador , Juergen Gross , Tony Luck , Mathieu Malaterre , Greg Kroah-Hartman , "Rafael J. Wysocki" , linux-kernel@vger.kernel.org, Fenghua Yu , Mauricio Faria de Oliveira , Thomas Gleixner , Philippe Ombredanne , Martin Schwidefsky , devel@linuxdriverproject.org, Andrew Morton , linuxppc-dev@lists.ozlabs.org, "Kirill A. Shutemov" Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Mon, 26 Nov 2018 14:33:29 +0100 David Hildenbrand wrote: > On 26.11.18 13:30, David Hildenbrand wrote: > > On 23.11.18 19:06, Michal Such=C3=A1nek wrote: =20 > >> > >> If we are going to fake the driver information we may as well add the > >> type attribute and be done with it. > >> > >> I think the problem with the patch was more with the semantic than the > >> attribute itself. > >> > >> What is normal, paravirtualized, and standby memory? > >> > >> I can understand DIMM device, baloon device, or whatever mechanism for > >> adding memory you might have. > >> > >> I can understand "memory designated as standby by the cluster > >> administrator". > >> > >> However, DIMM vs baloon is orthogonal to standby and should not be > >> conflated into one property. > >> > >> paravirtualized means nothing at all in relationship to memory type and > >> the desired online policy to me. =20 > >=20 > > Right, so with whatever we come up, it should allow to make a decision > > in user space about > > - if memory is to be onlined automatically =20 >=20 > And I will think about if we really should model standby memory. Maybe > it is really better to have in user space something like (as Dan noted) If it is possible to designate the memory as standby or online in the s390 admin interface and the kernel does have access to this information it makes sense to forward it to userspace (as separate s390-specific property). If not then you need to make some kind of assumption like below and the user can tune the script according to their usecase. >=20 > if (isS390x() && type =3D=3D "dimm") { > /* don't online, on s390x system DIMMs are standby memory */ > } Thanks Michal