From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ed1-f71.google.com (mail-ed1-f71.google.com [209.85.208.71]) by kanga.kvack.org (Postfix) with ESMTP id 722936B000E for ; Thu, 4 Oct 2018 13:50:17 -0400 (EDT) Received: by mail-ed1-f71.google.com with SMTP id x20-v6so5932777eda.21 for ; Thu, 04 Oct 2018 10:50:17 -0700 (PDT) Received: from mx1.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id n8si4211000edy.344.2018.10.04.10.50.16 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 04 Oct 2018 10:50:16 -0700 (PDT) Date: Thu, 4 Oct 2018 19:50:10 +0200 From: Michal =?UTF-8?B?U3VjaMOhbmVr?= Subject: Re: [PATCH RFC] mm/memory_hotplug: Introduce memory block types Message-ID: <20181004195010.3616fc40@kitsune.suse.cz> In-Reply-To: <14992b68-5402-9168-0050-b3c6ac4a8c90@redhat.com> References: <20181001084038.GD18290@dhcp22.suse.cz> <20181002134734.GT18290@dhcp22.suse.cz> <98fb8d65-b641-2225-f842-8804c6f79a06@redhat.com> <8736tndubn.fsf@vitty.brq.redhat.com> <20181003134444.GH4714@dhcp22.suse.cz> <87zhvvcf3b.fsf@vitty.brq.redhat.com> <49456818-238e-2d95-9df6-d1934e9c8b53@linux.intel.com> <87tvm3cd5w.fsf@vitty.brq.redhat.com> <06a35970-e478-18f8-eae6-4022925a5192@redhat.com> <20181004061938.GB22173@dhcp22.suse.cz> <20181004172807.1eef3a6b@kitsune.suse.cz> <14992b68-5402-9168-0050-b3c6ac4a8c90@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org List-ID: To: David Hildenbrand Cc: Kate Stewart , Rich Felker , linux-ia64@vger.kernel.org, linux-sh@vger.kernel.org, Peter Zijlstra , Dave Hansen , Heiko Carstens , Michal Hocko , linux-mm@kvack.org, Paul Mackerras , "H. Peter Anvin" , Rashmica Gupta , Boris Ostrovsky , Stephen Rothwell , Michael Neuling , Stephen Hemminger , Yoshinori Sato , Vitaly Kuznetsov , 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?SsOpcsO0?= =?UTF-8?B?bWU=?= Glisse , Mike Rapoport , Borislav Petkov , Andy Lutomirski , Dan Williams , Andrew Morton , 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, Joonsoo Kim , linuxppc-dev@lists.ozlabs.org, "Kirill A. Shutemov" On Thu, 4 Oct 2018 17:45:13 +0200 David Hildenbrand wrote: > On 04/10/2018 17:28, Michal Such=C3=A1nek wrote: > >=20 > > The state of the art is to determine what to do with hotplugged > > memory in userspace based on platform and virtualization type. =20 >=20 > Exactly. >=20 > >=20 > > Changing the default to depend on the driver that added the memory > > rather than platform type should solve the issue of VMs growing > > different types of memory device emulation. =20 >=20 > Yes, my original proposal (this patch) was to handle it in the kernel > for known types. But as we learned, there might be some use cases that > might still require to make a decision in user space. >=20 > So providing the user space either with some type hint (auto-online > vs. standby) or the driver that added it (system vs. hyper-v ...) > would solve the issue. Is that not available in the udev event? Thanks Michal