From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Hildenbrand Subject: Re: [PATCH RFC] mm/memory_hotplug: Introduce memory block types Date: Thu, 4 Oct 2018 09:40:56 +0200 Message-ID: <060bd891-f88e-13e1-2bb3-26d96f6d28cb@redhat.com> References: <20180928150357.12942-1-david@redhat.com> <20181001084038.GD18290@dhcp22.suse.cz> <20181002134734.GT18290@dhcp22.suse.cz> <98fb8d65-b641-2225-f842-8804c6f79a06@redhat.com> <20181003135407.GI4714@dhcp22.suse.cz> <9fef1f7d-2d7c-03f1-00e3-5fa657eda019@redhat.com> <20181004062811.GC22173@dhcp22.suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20181004062811.GC22173@dhcp22.suse.cz> Content-Language: en-US List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: driverdev-devel-bounces@linuxdriverproject.org Sender: "devel" To: Michal Hocko Cc: Kate Stewart , Rich Felker , linux-ia64@vger.kernel.org, linux-sh@vger.kernel.org, Peter Zijlstra , Benjamin Herrenschmidt , Balbir Singh , Dave Hansen , Heiko Carstens , linux-mm@kvack.org, Pavel Tatashin , Paul Mackerras , "H. Peter Anvin" , Rashmica Gupta , Boris Ostrovsky , linux-s390@vger.kernel.org, Michael Neuling , Stephen Hemminger , Yoshinori Sato , Michael Ellerman , linux-acpi@vger.kernel.org, Ingo Molnar , xen-devel@lists.xenproject.org, Rob Herring List-Id: linux-acpi@vger.kernel.org On 04/10/2018 08:28, Michal Hocko wrote: > On Wed 03-10-18 19:00:29, David Hildenbrand wrote: > [...] >> Let me rephrase: You state that user space has to make the decision and >> that user should be able to set/reconfigure rules. That is perfectly fine. >> >> But then we should give user space access to sufficient information to >> make a decision. This might be the type of memory as we learned (what >> some part of this patch proposes), but maybe later more, e.g. to which >> physical device memory belongs (e.g. to hotplug it all movable or all >> normal) ... > > I am pretty sure that user knows he/she wants to use ballooning in > HyperV or Xen, or that the memory hotplug should be used as a "RAS" > feature to allow add and remove DIMMs for reliability. Why shouldn't we > have a package to deploy an appropriate set of udev rules for each of > those usecases? I am pretty sure you need some other plumbing to enable > them anyway (e.g. RAS would require to have movable_node kernel > parameters, ballooning a kernel module etc.). > > Really, one udev script to rule them all will simply never work. > I am on your side. We will need multiple ones. But we need sane defaults. And a default rule will always exist. And users will expect that the defaults somewhat match their expectation unless they really have some special use cases. All I am saying is, again, that if user space is to make decisions, it should get sufficient information to make sane decision. And in my point of view, the type of memory allows us to make these decision and to provide a "single udev script to rule them all" with sane defaults. I at least think the distinction between "auto-online" and "standby" is required (what Dave suggested). The we can make a simple rule if (auto-online memory) { if (virtual environment) { "online" } else { "online_movable" } } /* standby memory not onlined as default */ We are able to provide sane defaults. -- Thanks, David / dhildenb From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt1-f200.google.com (mail-qt1-f200.google.com [209.85.160.200]) by kanga.kvack.org (Postfix) with ESMTP id E6BA06B0269 for ; Thu, 4 Oct 2018 03:41:12 -0400 (EDT) Received: by mail-qt1-f200.google.com with SMTP id k10-v6so7453843qtb.8 for ; Thu, 04 Oct 2018 00:41:12 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id i15-v6si1525031qvk.86.2018.10.04.00.41.11 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 04 Oct 2018 00:41:11 -0700 (PDT) Subject: Re: [PATCH RFC] mm/memory_hotplug: Introduce memory block types References: <20180928150357.12942-1-david@redhat.com> <20181001084038.GD18290@dhcp22.suse.cz> <20181002134734.GT18290@dhcp22.suse.cz> <98fb8d65-b641-2225-f842-8804c6f79a06@redhat.com> <20181003135407.GI4714@dhcp22.suse.cz> <9fef1f7d-2d7c-03f1-00e3-5fa657eda019@redhat.com> <20181004062811.GC22173@dhcp22.suse.cz> From: David Hildenbrand Message-ID: <060bd891-f88e-13e1-2bb3-26d96f6d28cb@redhat.com> Date: Thu, 4 Oct 2018 09:40:56 +0200 MIME-Version: 1.0 In-Reply-To: <20181004062811.GC22173@dhcp22.suse.cz> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: linux-mm@kvack.org, xen-devel@lists.xenproject.org, devel@linuxdriverproject.org, linux-acpi@vger.kernel.org, linux-sh@vger.kernel.org, linux-s390@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org, Tony Luck , Fenghua Yu , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Martin Schwidefsky , Heiko Carstens , Yoshinori Sato , Rich Felker , Dave Hansen , Andy Lutomirski , Peter Zijlstra , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , "Rafael J. Wysocki" , Len Brown , Greg Kroah-Hartman , "K. Y. Srinivasan" , Haiyang Zhang , Stephen Hemminger , Boris Ostrovsky , Juergen Gross , =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= , Andrew Morton , Mike Rapoport , Dan Williams , Stephen Rothwell , "Kirill A. Shutemov" , Nicholas Piggin , =?UTF-8?Q?Jonathan_Neusch=c3=a4fer?= , Joe Perches , Michael Neuling , Mauricio Faria de Oliveira , Balbir Singh , Rashmica Gupta , Pavel Tatashin , Rob Herring , Philippe Ombredanne , Kate Stewart , "mike.travis@hpe.com" , Joonsoo Kim , Oscar Salvador , Mathieu Malaterre On 04/10/2018 08:28, Michal Hocko wrote: > On Wed 03-10-18 19:00:29, David Hildenbrand wrote: > [...] >> Let me rephrase: You state that user space has to make the decision and >> that user should be able to set/reconfigure rules. That is perfectly fine. >> >> But then we should give user space access to sufficient information to >> make a decision. This might be the type of memory as we learned (what >> some part of this patch proposes), but maybe later more, e.g. to which >> physical device memory belongs (e.g. to hotplug it all movable or all >> normal) ... > > I am pretty sure that user knows he/she wants to use ballooning in > HyperV or Xen, or that the memory hotplug should be used as a "RAS" > feature to allow add and remove DIMMs for reliability. Why shouldn't we > have a package to deploy an appropriate set of udev rules for each of > those usecases? I am pretty sure you need some other plumbing to enable > them anyway (e.g. RAS would require to have movable_node kernel > parameters, ballooning a kernel module etc.). > > Really, one udev script to rule them all will simply never work. > I am on your side. We will need multiple ones. But we need sane defaults. And a default rule will always exist. And users will expect that the defaults somewhat match their expectation unless they really have some special use cases. All I am saying is, again, that if user space is to make decisions, it should get sufficient information to make sane decision. And in my point of view, the type of memory allows us to make these decision and to provide a "single udev script to rule them all" with sane defaults. I at least think the distinction between "auto-online" and "standby" is required (what Dave suggested). The we can make a simple rule if (auto-online memory) { if (virtual environment) { "online" } else { "online_movable" } } /* standby memory not onlined as default */ We are able to provide sane defaults. -- Thanks, David / dhildenb 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=-0.8 required=3.0 tests=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 D785EC64EB8 for ; Thu, 4 Oct 2018 07:43:11 +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 45FE22098A for ; Thu, 4 Oct 2018 07:43:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 45FE22098A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com 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 42QlHK25wVzF3Hd for ; Thu, 4 Oct 2018 17:43:09 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: lists.ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=redhat.com (client-ip=209.132.183.28; helo=mx1.redhat.com; envelope-from=david@redhat.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=redhat.com Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 42QlF61DXHzF3BS for ; Thu, 4 Oct 2018 17:41:13 +1000 (AEST) Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 6DA7E4E91C; Thu, 4 Oct 2018 07:41:09 +0000 (UTC) Received: from [10.36.117.44] (ovpn-117-44.ams2.redhat.com [10.36.117.44]) by smtp.corp.redhat.com (Postfix) with ESMTP id 194861823E; Thu, 4 Oct 2018 07:40:56 +0000 (UTC) Subject: Re: [PATCH RFC] mm/memory_hotplug: Introduce memory block types To: Michal Hocko References: <20180928150357.12942-1-david@redhat.com> <20181001084038.GD18290@dhcp22.suse.cz> <20181002134734.GT18290@dhcp22.suse.cz> <98fb8d65-b641-2225-f842-8804c6f79a06@redhat.com> <20181003135407.GI4714@dhcp22.suse.cz> <9fef1f7d-2d7c-03f1-00e3-5fa657eda019@redhat.com> <20181004062811.GC22173@dhcp22.suse.cz> From: David Hildenbrand Openpgp: preference=signencrypt Autocrypt: addr=david@redhat.com; prefer-encrypt=mutual; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzSREYXZpZCBIaWxk ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT7CwX4EEwECACgFAljj9eoCGwMFCQlmAYAGCwkI BwMCBhUIAgkKCwQWAgMBAh4BAheAAAoJEE3eEPcA/4Na5IIP/3T/FIQMxIfNzZshIq687qgG 8UbspuE/YSUDdv7r5szYTK6KPTlqN8NAcSfheywbuYD9A4ZeSBWD3/NAVUdrCaRP2IvFyELj xoMvfJccbq45BxzgEspg/bVahNbyuBpLBVjVWwRtFCUEXkyazksSv8pdTMAs9IucChvFmmq3 jJ2vlaz9lYt/lxN246fIVceckPMiUveimngvXZw21VOAhfQ+/sofXF8JCFv2mFcBDoa7eYob s0FLpmqFaeNRHAlzMWgSsP80qx5nWWEvRLdKWi533N2vC/EyunN3HcBwVrXH4hxRBMco3jvM m8VKLKao9wKj82qSivUnkPIwsAGNPdFoPbgghCQiBjBe6A75Z2xHFrzo7t1jg7nQfIyNC7ez MZBJ59sqA9EDMEJPlLNIeJmqslXPjmMFnE7Mby/+335WJYDulsRybN+W5rLT5aMvhC6x6POK z55fMNKrMASCzBJum2Fwjf/VnuGRYkhKCqqZ8gJ3OvmR50tInDV2jZ1DQgc3i550T5JDpToh dPBxZocIhzg+MBSRDXcJmHOx/7nQm3iQ6iLuwmXsRC6f5FbFefk9EjuTKcLMvBsEx+2DEx0E UnmJ4hVg7u1PQ+2Oy+Lh/opK/BDiqlQ8Pz2jiXv5xkECvr/3Sv59hlOCZMOaiLTTjtOIU7Tq 7ut6OL64oAq+zsFNBFXLn5EBEADn1959INH2cwYJv0tsxf5MUCghCj/CA/lc/LMthqQ773ga uB9mN+F1rE9cyyXb6jyOGn+GUjMbnq1o121Vm0+neKHUCBtHyseBfDXHA6m4B3mUTWo13nid 0e4AM71r0DS8+KYh6zvweLX/LL5kQS9GQeT+QNroXcC1NzWbitts6TZ+IrPOwT1hfB4WNC+X 2n4AzDqp3+ILiVST2DT4VBc11Gz6jijpC/KI5Al8ZDhRwG47LUiuQmt3yqrmN63V9wzaPhC+ xbwIsNZlLUvuRnmBPkTJwwrFRZvwu5GPHNndBjVpAfaSTOfppyKBTccu2AXJXWAE1Xjh6GOC 8mlFjZwLxWFqdPHR1n2aPVgoiTLk34LR/bXO+e0GpzFXT7enwyvFFFyAS0Nk1q/7EChPcbRb hJqEBpRNZemxmg55zC3GLvgLKd5A09MOM2BrMea+l0FUR+PuTenh2YmnmLRTro6eZ/qYwWkC u8FFIw4pT0OUDMyLgi+GI1aMpVogTZJ70FgV0pUAlpmrzk/bLbRkF3TwgucpyPtcpmQtTkWS gDS50QG9DR/1As3LLLcNkwJBZzBG6PWbvcOyrwMQUF1nl4SSPV0LLH63+BrrHasfJzxKXzqg rW28CTAE2x8qi7e/6M/+XXhrsMYG+uaViM7n2je3qKe7ofum3s4vq7oFCPsOgwARAQABwsFl BBgBAgAPBQJVy5+RAhsMBQkJZgGAAAoJEE3eEPcA/4NagOsP/jPoIBb/iXVbM+fmSHOjEshl KMwEl/m5iLj3iHnHPVLBUWrXPdS7iQijJA/VLxjnFknhaS60hkUNWexDMxVVP/6lbOrs4bDZ NEWDMktAeqJaFtxackPszlcpRVkAs6Msn9tu8hlvB517pyUgvuD7ZS9gGOMmYwFQDyytpepo YApVV00P0u3AaE0Cj/o71STqGJKZxcVhPaZ+LR+UCBZOyKfEyq+ZN311VpOJZ1IvTExf+S/5 lqnciDtbO3I4Wq0ArLX1gs1q1XlXLaVaA3yVqeC8E7kOchDNinD3hJS4OX0e1gdsx/e6COvy qNg5aL5n0Kl4fcVqM0LdIhsubVs4eiNCa5XMSYpXmVi3HAuFyg9dN+x8thSwI836FoMASwOl C7tHsTjnSGufB+D7F7ZBT61BffNBBIm1KdMxcxqLUVXpBQHHlGkbwI+3Ye+nE6HmZH7IwLwV W+Ajl7oYF+jeKaH4DZFtgLYGLtZ1LDwKPjX7VAsa4Yx7S5+EBAaZGxK510MjIx6SGrZWBrrV TEvdV00F2MnQoeXKzD7O4WFbL55hhyGgfWTHwZ457iN9SgYi1JLPqWkZB0JRXIEtjd4JEQcx +8Umfre0Xt4713VxMygW0PnQt5aSQdMD58jHFxTk092mU+yIHj5LeYgvwSgZN4airXk5yRXl SE+xAvmumFBY Organization: Red Hat GmbH Message-ID: <060bd891-f88e-13e1-2bb3-26d96f6d28cb@redhat.com> Date: Thu, 4 Oct 2018 09:40:56 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.0 MIME-Version: 1.0 In-Reply-To: <20181004062811.GC22173@dhcp22.suse.cz> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Thu, 04 Oct 2018 07:41:11 +0000 (UTC) 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, Pavel Tatashin , Paul Mackerras , "H. Peter Anvin" , Rashmica Gupta , "K. Y. Srinivasan" , Boris Ostrovsky , linux-s390@vger.kernel.org, Michael Neuling , Stephen Hemminger , Yoshinori Sato , linux-acpi@vger.kernel.org, Ingo Molnar , xen-devel@lists.xenproject.org, Rob Herring , Len Brown , Fenghua Yu , Stephen Rothwell , "mike.travis@hpe.com" , Haiyang Zhang , Dan Williams , =?UTF-8?Q?Jonathan_Neusch=c3=a4fer?= , Nicholas Piggin , Joe Perches , =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= , Mike Rapoport , Borislav Petkov , Andy Lutomirski , Thomas Gleixner , Joonsoo Kim , Oscar Salvador , Juergen Gross , Tony Luck , Mathieu Malaterre , Greg Kroah-Hartman , "Rafael J. Wysocki" , linux-kernel@vger.kernel.org, Mauricio Faria de Oliveira , 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 04/10/2018 08:28, Michal Hocko wrote: > On Wed 03-10-18 19:00:29, David Hildenbrand wrote: > [...] >> Let me rephrase: You state that user space has to make the decision and >> that user should be able to set/reconfigure rules. That is perfectly fine. >> >> But then we should give user space access to sufficient information to >> make a decision. This might be the type of memory as we learned (what >> some part of this patch proposes), but maybe later more, e.g. to which >> physical device memory belongs (e.g. to hotplug it all movable or all >> normal) ... > > I am pretty sure that user knows he/she wants to use ballooning in > HyperV or Xen, or that the memory hotplug should be used as a "RAS" > feature to allow add and remove DIMMs for reliability. Why shouldn't we > have a package to deploy an appropriate set of udev rules for each of > those usecases? I am pretty sure you need some other plumbing to enable > them anyway (e.g. RAS would require to have movable_node kernel > parameters, ballooning a kernel module etc.). > > Really, one udev script to rule them all will simply never work. > I am on your side. We will need multiple ones. But we need sane defaults. And a default rule will always exist. And users will expect that the defaults somewhat match their expectation unless they really have some special use cases. All I am saying is, again, that if user space is to make decisions, it should get sufficient information to make sane decision. And in my point of view, the type of memory allows us to make these decision and to provide a "single udev script to rule them all" with sane defaults. I at least think the distinction between "auto-online" and "standby" is required (what Dave suggested). The we can make a simple rule if (auto-online memory) { if (virtual environment) { "online" } else { "online_movable" } } /* standby memory not onlined as default */ We are able to provide sane defaults. -- Thanks, David / dhildenb