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=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 1E762C10F27 for ; Tue, 10 Mar 2020 11:20:51 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id C2D9624684 for ; Tue, 10 Mar 2020 11:20:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Uo/FcNWI" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C2D9624684 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 6C7436B0005; Tue, 10 Mar 2020 07:20:50 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 651006B0006; Tue, 10 Mar 2020 07:20:50 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 519466B0007; Tue, 10 Mar 2020 07:20:50 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0168.hostedemail.com [216.40.44.168]) by kanga.kvack.org (Postfix) with ESMTP id 3544F6B0005 for ; Tue, 10 Mar 2020 07:20:50 -0400 (EDT) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 33BD72478 for ; Tue, 10 Mar 2020 11:20:50 +0000 (UTC) X-FDA: 76579210260.23.pigs89_245983885d75c X-HE-Tag: pigs89_245983885d75c X-Filterd-Recvd-Size: 9671 Received: from us-smtp-delivery-1.mimecast.com (us-smtp-2.mimecast.com [207.211.31.81]) by imf25.hostedemail.com (Postfix) with ESMTP for ; Tue, 10 Mar 2020 11:20:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1583839248; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=GdVuc9bDDGHvyHDl3iZh6HgXHzBZaac/Yra+QM5W/hE=; b=Uo/FcNWI4IvH/RIAW6QakCfTyCFs+usq2aozgkfKgTB3D06wblbw7fWOGIllzm3UvAjxyJ GJIRvCb5lUnuZGATDb29omXqZN0saNc9YV43paZy/MpoaCXoISfnD5g4piCLaEDmWhaaGt E1jYn5xEBMHQVZmcHT2eNdEkrSMwPds= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-121-FCPBD8E8NIODu9xpGVJgJw-1; Tue, 10 Mar 2020 07:20:45 -0400 X-MC-Unique: FCPBD8E8NIODu9xpGVJgJw-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 5CD1E10120DD; Tue, 10 Mar 2020 11:20:42 +0000 (UTC) Received: from [10.36.118.8] (unknown [10.36.118.8]) by smtp.corp.redhat.com (Postfix) with ESMTP id 389DF10013A1; Tue, 10 Mar 2020 11:20:37 +0000 (UTC) Subject: Re: [PATCH v2] virtio-balloon: Switch back to OOM handler for VIRTIO_BALLOON_F_DEFLATE_ON_OOM To: "Michael S. Tsirkin" Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, virtualization@lists.linux-foundation.org, Jason Wang , Stephen Rothwell , Tyler Sanderson , Wei Wang , Alexander Duyck , David Rientjes , Nadav Amit , Michal Hocko , Andrew Morton References: <20200310103903.6014-1-david@redhat.com> <20200310070413-mutt-send-email-mst@kernel.org> <78427916-fc17-b081-6b1e-cbcb00d51752@redhat.com> <20200310071844-mutt-send-email-mst@kernel.org> From: David Hildenbrand Autocrypt: addr=david@redhat.com; prefer-encrypt=mutual; keydata= mQINBFXLn5EBEAC+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 B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABtCREYXZpZCBIaWxk ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT6JAlgEEwEIAEICGwMFCQlmAYAGCwkIBwMCBhUI AgkKCwQWAgMBAh4BAheAFiEEG9nKrXNcTDpGDfzKTd4Q9wD/g1oFAl3pImkCGQEACgkQTd4Q 9wD/g1o+VA//SFvIHUAvul05u6wKv/pIR6aICPdpF9EIgEU448g+7FfDgQwcEny1pbEzAmiw zAXIQ9H0NZh96lcq+yDLtONnXk/bEYWHHUA014A1wqcYNRY8RvY1+eVHb0uu0KYQoXkzvu+s Dncuguk470XPnscL27hs8PgOP6QjG4jt75K2LfZ0eAqTOUCZTJxA8A7E9+XTYuU0hs7QVrWJ jQdFxQbRMrYz7uP8KmTK9/Cnvqehgl4EzyRaZppshruKMeyheBgvgJd5On1wWq4ZUV5PFM4x II3QbD3EJfWbaJMR55jI9dMFa+vK7MFz3rhWOkEx/QR959lfdRSTXdxs8V3zDvChcmRVGN8U Vo93d1YNtWnA9w6oCW1dnDZ4kgQZZSBIjp6iHcA08apzh7DPi08jL7M9UQByeYGr8KuR4i6e RZI6xhlZerUScVzn35ONwOC91VdYiQgjemiVLq1WDDZ3B7DIzUZ4RQTOaIWdtXBWb8zWakt/ ztGhsx0e39Gvt3391O1PgcA7ilhvqrBPemJrlb9xSPPRbaNAW39P8ws/UJnzSJqnHMVxbRZC Am4add/SM+OCP0w3xYss1jy9T+XdZa0lhUvJfLy7tNcjVG/sxkBXOaSC24MFPuwnoC9WvCVQ ZBxouph3kqc4Dt5X1EeXVLeba+466P1fe1rC8MbcwDkoUo65Ag0EVcufkQEQAOfX3n0g0fZz Bgm/S2zF/kxQKCEKP8ID+Vz8sy2GpDvveBq4H2Y34XWsT1zLJdvqPI4af4ZSMxuerWjXbVWb T6d4odQIG0fKx4F8NccDqbgHeZRNajXeeJ3R7gAzvWvQNLz4piHrO/B4tf8svmRBL0ZB5P5A 2uhdwLU3NZuK22zpNn4is87BPWF8HhY0L5fafgDMOqnf4guJVJPYNPhUFzXUbPqOKOkL8ojk CXxkOFHAbjstSK5Ca3fKquY3rdX3DNo+EL7FvAiw1mUtS+5GeYE+RMnDCsVFm/C7kY8c2d0G NWkB9pJM5+mnIoFNxy7YBcldYATVeOHoY4LyaUWNnAvFYWp08dHWfZo9WCiJMuTfgtH9tc75 7QanMVdPt6fDK8UUXIBLQ2TWr/sQKE9xtFuEmoQGlE1l6bGaDnnMLcYu+Asp3kDT0w4zYGsx 5r6XQVRH4+5N6eHZiaeYtFOujp5n+pjBaQK7wUUjDilPQ5QMzIuCL4YjVoylWiBNknvQWBXS lQCWmavOT9sttGQXdPCC5ynI+1ymZC1ORZKANLnRAb0NH/UCzcsstw2TAkFnMEbo9Zu9w7Kv AxBQXWeXhJI9XQssfrf4Gusdqx8nPEpfOqCtbbwJMATbHyqLt7/oz/5deGuwxgb65pWIzufa N7eop7uh+6bezi+rugUI+w6DABEBAAGJAiUEGAECAA8FAlXLn5ECGwwFCQlmAYAACgkQTd4Q 9wD/g1qA6w/+M+ggFv+JdVsz5+ZIc6MSyGUozASX+bmIuPeIecc9UsFRatc91LuJCKMkD9Uv GOcWSeFpLrSGRQ1Z7EMzFVU//qVs6uzhsNk0RYMyS0B6oloW3FpyQ+zOVylFWQCzoyyf227y GW8HnXunJSC+4PtlL2AY4yZjAVAPLK2l6mhgClVXTQ/S7cBoTQKP+jvVJOoYkpnFxWE9pn4t H5QIFk7Ip8TKr5k3fXVWk4lnUi9MTF/5L/mWqdyIO1s7cjharQCstfWCzWrVeVctpVoDfJWp 4LwTuQ5yEM2KcPeElLg5fR7WB2zH97oI6/Ko2DlovmfQqXh9xWozQt0iGy5tWzh6I0JrlcxJ ileZWLccC4XKD1037Hy2FLAjzfoWgwBLA6ULu0exOOdIa58H4PsXtkFPrUF980EEibUp0zFz GotRVekFAceUaRvAj7dh76cToeZkfsjAvBVb4COXuhgX6N4pofgNkW2AtgYu1nUsPAo+NftU CxrhjHtLn4QEBpkbErnXQyMjHpIatlYGutVMS91XTQXYydCh5crMPs7hYVsvnmGHIaB9ZMfB njnuI31KBiLUks+paRkHQlFcgS2N3gkRBzH7xSZ+t7Re3jvXdXEzKBbQ+dC3lpJB0wPnyMcX FOTT3aZT7IgePkt5iC/BKBk3hqKteTnJFeVIT7EC+a6YUFg= Organization: Red Hat GmbH Message-ID: Date: Tue, 10 Mar 2020 12:20:36 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0 MIME-Version: 1.0 In-Reply-To: <20200310071844-mutt-send-email-mst@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 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 10.03.20 12:19, Michael S. Tsirkin wrote: > On Tue, Mar 10, 2020 at 12:12:50PM +0100, David Hildenbrand wrote: >>>> static void virtio_balloon_unregister_shrinker(struct virtio_balloon *vb) >>>> @@ -971,7 +950,22 @@ static int virtballoon_probe(struct virtio_device *vdev) >>>> VIRTIO_BALLOON_CMD_ID_STOP); >>>> spin_lock_init(&vb->free_page_list_lock); >>>> INIT_LIST_HEAD(&vb->free_page_list); >>>> + /* >>>> + * We're allowed to reuse any free pages, even if they are >>>> + * still to be processed by the host. >>>> + */ >>>> + err = virtio_balloon_register_shrinker(vb); >>>> + if (err) >>>> + goto out_del_balloon_wq; >>>> } >>>> + if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_DEFLATE_ON_OOM)) { >>>> + vb->oom_nb.notifier_call = virtio_balloon_oom_notify; >>>> + vb->oom_nb.priority = VIRTIO_BALLOON_OOM_NOTIFY_PRIORITY; >>>> + err = register_oom_notifier(&vb->oom_nb); >>>> + if (err < 0) >>>> + goto out_unregister_shrinker; >>>> + } >>>> + >>> >>> >>> Let's decide whether we want an empty line after }, or not, and stick to >>> it. I prefer an empty line but no biggie as long as we are consistent. >> >> Can add one. >> >>> >>>> if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_PAGE_POISON)) { >>>> /* Start with poison val of 0 representing general init */ >>>> __u32 poison_val = 0; >>>> @@ -986,15 +980,6 @@ static int virtballoon_probe(struct virtio_device *vdev) >>>> virtio_cwrite(vb->vdev, struct virtio_balloon_config, >>>> poison_val, &poison_val); >>>> } >>>> - /* >>>> - * We continue to use VIRTIO_BALLOON_F_DEFLATE_ON_OOM to decide if a >>>> - * shrinker needs to be registered to relieve memory pressure. >>>> - */ >>>> - if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_DEFLATE_ON_OOM)) { >>>> - err = virtio_balloon_register_shrinker(vb); >>>> - if (err) >>>> - goto out_del_balloon_wq; >>>> - } >>>> >>>> vb->pr_dev_info.report = virtballoon_free_page_report; >>>> if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_REPORTING)) { >>>> @@ -1003,12 +988,12 @@ static int virtballoon_probe(struct virtio_device *vdev) >>>> capacity = virtqueue_get_vring_size(vb->reporting_vq); >>>> if (capacity < PAGE_REPORTING_CAPACITY) { >>>> err = -ENOSPC; >>>> - goto out_unregister_shrinker; >>>> + goto out_unregister_oom; >>>> } >>>> >>>> err = page_reporting_register(&vb->pr_dev_info); >>>> if (err) >>>> - goto out_unregister_shrinker; >>>> + goto out_unregister_oom; >>>> } >>>> >>>> virtio_device_ready(vdev); >>>> @@ -1017,8 +1002,11 @@ static int virtballoon_probe(struct virtio_device *vdev) >>>> virtballoon_changed(vdev); >>>> return 0; >>>> >>>> +out_unregister_oom: >>>> + if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_DEFLATE_ON_OOM)) >>>> + unregister_oom_notifier(&vb->oom_nb); >>>> out_unregister_shrinker: >>>> - if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_DEFLATE_ON_OOM)) >>>> + if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT)) >>>> virtio_balloon_unregister_shrinker(vb); >>> >>> >>> What's with vdev versus vb->vdev here? >>> I suggest we keep using vb->vdev to make the patch minimal if we can. >>> Same elsewhere. >> >> As we touch this line either way, does it really make a difference? No >> strong opinion. Can just do a vb->vdev and clean this up globally later. >> > > Let's just be consistent. I guess that means keep using vb->vdev > everywhere. It's already really inconsistent, so I'll use vb->vdev in this patch and cleanup the other users later. -- Thanks, David / dhildenb