From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Hildenbrand Subject: Re: [PATCH v2 07/10] mm/memory_hotplug: Introduce offline_and_remove_memory() Date: Wed, 11 Mar 2020 18:19:04 +0100 Message-ID: <156601a9-e919-b88f-2278-97ecee554d21@redhat.com> References: <20200311171422.10484-1-david@redhat.com> <20200311171422.10484-8-david@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20200311171422.10484-8-david@redhat.com> Content-Language: en-US Sender: kvm-owner@vger.kernel.org To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, virtio-dev@lists.oasis-open.org, virtualization@lists.linux-foundation.org, kvm@vger.kernel.org, Michal Hocko , Andrew Morton , "Michael S . Tsirkin" , Oscar Salvador , Michal Hocko , Pavel Tatashin , Wei Yang , Dan Williams , Qian Cai List-Id: virtualization@lists.linuxfoundation.org On 11.03.20 18:14, David Hildenbrand wrote: > virtio-mem wants to offline and remove a memory block once it unplugged > all subblocks (e.g., using alloc_contig_range()). Let's provide > an interface to do that from a driver. virtio-mem already supports to > offline partially unplugged memory blocks. Offlining a fully unplugged > memory block will not require to migrate any pages. All unplugged > subblocks are PageOffline() and have a reference count of 0 - so > offlining code will simply skip them. > > All we need is an interface to offline and remove the memory from kernel > module context, where we don't have access to the memory block devices > (esp. find_memory_block() and device_offline()) and the device hotplug > lock. > > To keep things simple, allow to only work on a single memory block. > Lost the ACK from Michael Acked-by: Michal Hocko [1] [1] https://lkml.kernel.org/r/20200302142737.GP4380@dhcp22.suse.cz -- Thanks, David / dhildenb