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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,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 3DDABC433DF for ; Fri, 5 Jun 2020 10:09:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 133AB207F9 for ; Fri, 5 Jun 2020 10:09:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726349AbgFEKJE (ORCPT ); Fri, 5 Jun 2020 06:09:04 -0400 Received: from out30-44.freemail.mail.aliyun.com ([115.124.30.44]:45717 "EHLO out30-44.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725926AbgFEKJD (ORCPT ); Fri, 5 Jun 2020 06:09:03 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R441e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e01355;MF=alex.shi@linux.alibaba.com;NM=1;PH=DS;RN=39;SR=0;TI=SMTPD_---0U-dqblm_1591351735; Received: from IT-FVFX43SYHV2H.local(mailfrom:alex.shi@linux.alibaba.com fp:SMTPD_---0U-dqblm_1591351735) by smtp.aliyun-inc.com(127.0.0.1); Fri, 05 Jun 2020 18:08:56 +0800 Subject: Re: [PATCH RFC v4 00/13] virtio-mem: paravirtualized memory To: David Hildenbrand , 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" , Sebastien Boeuf , Samuel Ortiz , Robert Bradford , Luiz Capitulino , Alexander Duyck , Alexander Potapenko , Alexander Viro , Anshuman Khandual , Anthony Yznaga , Dan Williams , Dave Young , Igor Mammedov , Jason Wang , Johannes Weiner , Juergen Gross , Konrad Rzeszutek Wilk , Len Brown , Mel Gorman , Michal Hocko , Mike Rapoport , Oscar Salvador , Oscar Salvador , Pavel Tatashin , Pavel Tatashin , Pingfan Liu , Qian Cai , "Rafael J. Wysocki" , Stefan Hajnoczi , Vlastimil Babka , Wei Yang References: <20191212171137.13872-1-david@redhat.com> <9acc5d04-c8e9-ef53-85e4-709030997ca6@redhat.com> <1cfa9edb-47ea-1495-4e28-4cf391eab44c@linux.alibaba.com> <6b4724bf-84b5-9880-5464-1908425d106d@redhat.com> From: Alex Shi Message-ID: <741e7d4b-4433-98fc-f849-cbb460d61a41@linux.alibaba.com> Date: Fri, 5 Jun 2020 18:08:55 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: <6b4724bf-84b5-9880-5464-1908425d106d@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 在 2020/6/5 下午5:36, David Hildenbrand 写道: > I guess I know what's happening here. In case we only have DMA memory > when booting, we don't reserve swiotlb buffers. Once we hotplug memory > and online ZONE_NORMAL, we don't have any swiotlb DMA bounce buffers to > map such PFNs (total 0 (slots), used 0 (slots)). > > Can you try with "swiotlb=force" on the kernel cmdline? Yes, it works fine with this cmdline. problems gone,