From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by dpdk.org (Postfix) with ESMTP id 472E11B1A3 for ; Wed, 6 Dec 2017 12:23:25 +0100 (CET) Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 8BFD5C0568F9; Wed, 6 Dec 2017 11:23:24 +0000 (UTC) Received: from [10.36.112.55] (ovpn-112-55.ams2.redhat.com [10.36.112.55]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 58B4B61781; Wed, 6 Dec 2017 11:23:23 +0000 (UTC) To: "Wang, Wei 5. (NSB - CN/Hangzhou)" , "dev@dpdk.org" References: From: Maxime Coquelin Cc: Yuanhan Liu Message-ID: <85be48c8-4d6a-225d-3451-2d9509d96135@redhat.com> Date: Wed, 6 Dec 2017 12:23:19 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.4.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Wed, 06 Dec 2017 11:23:24 +0000 (UTC) Subject: Re: [dpdk-dev] The limitation of VHOST_MEMORY_MAX_NREGIONS in virtio-user with vhost-user backend X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 06 Dec 2017 11:23:25 -0000 Hi, On 12/05/2017 07:58 AM, Wang, Wei 5. (NSB - CN/Hangzhou) wrote: > > > Hi, all > > In DPDK document, it it described that Virtio in containers Cannot work when there are more than VHOST_MEMORY_MAX_NREGIONS(8) hugepages. In another word, do not use 2MB hugepage so far. Do you know the reason of this limitation? What document are you referring to? Actually, a single region is composed of several hugepages, be it 1G or 2M. I use 2M hugepages daily without issues. The limitation comes from the Vhost-user protocol spec. I know there are discussions to enlarge it, but it would require a new protocol flag not to break existing implementations, so no workaround possible. > In my envirionment, the pdpe1gb is not set in cpu flag, so hugepage can't be set to 1GB size. The hugepage number shall be more than 8 > > > So is there any solution or workaround to fix this limitation? Or change dpdk code to fix this limitation? Have you tried to use 2MB pages and faced the NREGIONS > 8 case? If so, could you tell us more about your setup (QEMU version, VM RAM size, etc...)? Cheers, Maxime > > > Vivian > seat: 19009 > phone: 13738006921 > > >