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=-9.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 7AE3DC56202 for ; Thu, 12 Nov 2020 13:39:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1CADF2224A for ; Thu, 12 Nov 2020 13:39:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Td2tVPjR" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728421AbgKLNjC (ORCPT ); Thu, 12 Nov 2020 08:39:02 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:48868 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728398AbgKLNi4 (ORCPT ); Thu, 12 Nov 2020 08:38:56 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1605188334; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=PkQpMojYRxFsLYxPlbZFOn8fec/qzZm0sDp3kHAbNA0=; b=Td2tVPjRvZRrTxFu+tOoke/ObskNorBnxFPzHxk1lcPqnHjtn0qf/p+bQrTmFGL7tRPlXf xWgUVz4R2sIhkOuBlCXZDacv8JpjeKYCL/7wIjITvVP0JhLf0TM0I5+tmchkLPWm1h6haC kyX5zSyokGynqkxibYXkJnL2uFWDoP0= 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-430-RXNbrCGMPiub07vAByCy4A-1; Thu, 12 Nov 2020 08:38:52 -0500 X-MC-Unique: RXNbrCGMPiub07vAByCy4A-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 73C641030988; Thu, 12 Nov 2020 13:38:51 +0000 (UTC) Received: from t480s.redhat.com (ovpn-115-61.ams2.redhat.com [10.36.115.61]) by smtp.corp.redhat.com (Postfix) with ESMTP id BAEE155765; Thu, 12 Nov 2020 13:38:49 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Cc: virtualization@lists.linux-foundation.org, linux-mm@kvack.org, "Michael S . Tsirkin" , David Hildenbrand , Wei Yang , Jason Wang , Pankaj Gupta Subject: [PATCH v2 09/29] virtio-mem: factor out handling of fake-offline pages in memory notifier Date: Thu, 12 Nov 2020 14:37:55 +0100 Message-Id: <20201112133815.13332-10-david@redhat.com> In-Reply-To: <20201112133815.13332-1-david@redhat.com> References: <20201112133815.13332-1-david@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Let's factor out the core pieces and place the implementation next to virtio_mem_fake_offline(). We'll reuse this functionality soon. Reviewed-by: Wei Yang Cc: "Michael S. Tsirkin" Cc: Jason Wang Cc: Pankaj Gupta Signed-off-by: David Hildenbrand --- drivers/virtio/virtio_mem.c | 73 +++++++++++++++++++++++++------------ 1 file changed, 50 insertions(+), 23 deletions(-) diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c index fedfea27967e..c24055248f9d 100644 --- a/drivers/virtio/virtio_mem.c +++ b/drivers/virtio/virtio_mem.c @@ -160,6 +160,10 @@ static DEFINE_MUTEX(virtio_mem_mutex); static LIST_HEAD(virtio_mem_devices); static void virtio_mem_online_page_cb(struct page *page, unsigned int order); +static void virtio_mem_fake_offline_going_offline(unsigned long pfn, + unsigned long nr_pages); +static void virtio_mem_fake_offline_cancel_offline(unsigned long pfn, + unsigned long nr_pages); /* * Register a virtio-mem device so it will be considered for the online_page @@ -586,27 +590,15 @@ static void virtio_mem_notify_going_offline(struct virtio_mem *vm, unsigned long mb_id) { const unsigned long nr_pages = PFN_DOWN(vm->subblock_size); - struct page *page; unsigned long pfn; - int sb_id, i; + int sb_id; for (sb_id = 0; sb_id < vm->nb_sb_per_mb; sb_id++) { if (virtio_mem_mb_test_sb_plugged(vm, mb_id, sb_id, 1)) continue; - /* - * Drop our reference to the pages so the memory can get - * offlined and add the unplugged pages to the managed - * page counters (so offlining code can correctly subtract - * them again). - */ pfn = PFN_DOWN(virtio_mem_mb_id_to_phys(mb_id) + sb_id * vm->subblock_size); - adjust_managed_page_count(pfn_to_page(pfn), nr_pages); - for (i = 0; i < nr_pages; i++) { - page = pfn_to_page(pfn + i); - if (WARN_ON(!page_ref_dec_and_test(page))) - dump_page(page, "unplugged page referenced"); - } + virtio_mem_fake_offline_going_offline(pfn, nr_pages); } } @@ -615,21 +607,14 @@ static void virtio_mem_notify_cancel_offline(struct virtio_mem *vm, { const unsigned long nr_pages = PFN_DOWN(vm->subblock_size); unsigned long pfn; - int sb_id, i; + int sb_id; for (sb_id = 0; sb_id < vm->nb_sb_per_mb; sb_id++) { if (virtio_mem_mb_test_sb_plugged(vm, mb_id, sb_id, 1)) continue; - /* - * Get the reference we dropped when going offline and - * subtract the unplugged pages from the managed page - * counters. - */ pfn = PFN_DOWN(virtio_mem_mb_id_to_phys(mb_id) + sb_id * vm->subblock_size); - adjust_managed_page_count(pfn_to_page(pfn), -nr_pages); - for (i = 0; i < nr_pages; i++) - page_ref_inc(pfn_to_page(pfn + i)); + virtio_mem_fake_offline_cancel_offline(pfn, nr_pages); } } @@ -814,6 +799,48 @@ static int virtio_mem_fake_offline(unsigned long pfn, unsigned long nr_pages) return 0; } +/* + * Handle fake-offline pages when memory is going offline - such that the + * pages can be skipped by mm-core when offlining. + */ +static void virtio_mem_fake_offline_going_offline(unsigned long pfn, + unsigned long nr_pages) +{ + struct page *page; + unsigned long i; + + /* + * Drop our reference to the pages so the memory can get offlined + * and add the unplugged pages to the managed page counters (so + * offlining code can correctly subtract them again). + */ + adjust_managed_page_count(pfn_to_page(pfn), nr_pages); + /* Drop our reference to the pages so the memory can get offlined. */ + for (i = 0; i < nr_pages; i++) { + page = pfn_to_page(pfn + i); + if (WARN_ON(!page_ref_dec_and_test(page))) + dump_page(page, "fake-offline page referenced"); + } +} + +/* + * Handle fake-offline pages when memory offlining is canceled - to undo + * what we did in virtio_mem_fake_offline_going_offline(). + */ +static void virtio_mem_fake_offline_cancel_offline(unsigned long pfn, + unsigned long nr_pages) +{ + unsigned long i; + + /* + * Get the reference we dropped when going offline and subtract the + * unplugged pages from the managed page counters. + */ + adjust_managed_page_count(pfn_to_page(pfn), -nr_pages); + for (i = 0; i < nr_pages; i++) + page_ref_inc(pfn_to_page(pfn + i)); +} + static void virtio_mem_online_page_cb(struct page *page, unsigned int order) { const unsigned long addr = page_to_phys(page); -- 2.26.2