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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 AD87DC2BB1D for ; Wed, 15 Apr 2020 00:30:50 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 520F620737 for ; Wed, 15 Apr 2020 00:30:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="GPwWVfeC" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 520F620737 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 9B3F18E0003; Tue, 14 Apr 2020 20:30:49 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 964B48E0001; Tue, 14 Apr 2020 20:30:49 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 87A268E0003; Tue, 14 Apr 2020 20:30:49 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0037.hostedemail.com [216.40.44.37]) by kanga.kvack.org (Postfix) with ESMTP id 6E1B18E0001 for ; Tue, 14 Apr 2020 20:30:49 -0400 (EDT) Received: from smtpin04.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 36780585F for ; Wed, 15 Apr 2020 00:30:49 +0000 (UTC) X-FDA: 76708209018.04.trick44_5e68cdb2cec4d X-HE-Tag: trick44_5e68cdb2cec4d X-Filterd-Recvd-Size: 3516 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf33.hostedemail.com (Postfix) with ESMTP for ; Wed, 15 Apr 2020 00:30:48 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 47F11206D9; Wed, 15 Apr 2020 00:30:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586910647; bh=jL66d2F3DmKs1s6SQQ+Gk7nBbbPMhZl6+fmVjYGZYK0=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=GPwWVfeCcSD4sp5mVFr9IDu41iwT/UEGE8CbjSF8HXKFDMv2LZp0R1EFTLZgTmfUY zrOhhvSS14vBZ2sye+oSCqGDhCp6DL1Qpf4iwi6WkQ2uEl5MsgOEAOo4LyS5RLvbLI RXpCxCZiweqq9m236ZzG6mYodR5MV59j5S5v24eU= Date: Tue, 14 Apr 2020 17:30:46 -0700 From: Andrew Morton To: "Michael S. Tsirkin" Cc: David Hildenbrand , linux-kernel@vger.kernel.org, linux-mm@kvack.org, virtio-dev@lists.oasis-open.org, virtualization@lists.linux-foundation.org, kvm@vger.kernel.org, Michal Hocko , Oscar Salvador , Michal Hocko , Pavel Tatashin , Wei Yang , Dan Williams , Qian Cai Subject: Re: [PATCH v2 07/10] mm/memory_hotplug: Introduce offline_and_remove_memory() Message-Id: <20200414173046.dc097faf7062f76a8c68f580@linux-foundation.org> In-Reply-To: <20200414123438-mutt-send-email-mst@kernel.org> References: <20200311171422.10484-1-david@redhat.com> <20200311171422.10484-8-david@redhat.com> <156601a9-e919-b88f-2278-97ecee554d21@redhat.com> <20200414123438-mutt-send-email-mst@kernel.org> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, 14 Apr 2020 12:35:02 -0400 "Michael S. Tsirkin" wrote: > On Wed, Mar 11, 2020 at 06:19:04PM +0100, David Hildenbrand wrote: > > 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 > > > Andrew, could you pls ack merging this through the vhost tree, > with the rest of the patchset? I wish the device_offline() return value was documented :( Yes, please go ahead and merge. Acked-by: Andrew Morton