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 6E4637D52; Fri, 8 Dec 2017 11:17:30 +0100 (CET) Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 835FB80B2A; Fri, 8 Dec 2017 10:17:29 +0000 (UTC) Received: from ktraynor.remote.csb (ovpn-116-183.ams2.redhat.com [10.36.116.183]) by smtp.corp.redhat.com (Postfix) with ESMTP id 054AA60BF3; Fri, 8 Dec 2017 10:17:24 +0000 (UTC) To: Tiwei Bie Cc: yliu@fridaylinux.org, maxime.coquelin@redhat.com, dev@dpdk.org, antonio.fischetti@intel.com, stable@dpdk.org, "Kavanagh, Mark B" References: <20171207053059.19487-1-tiwei.bie@intel.com> <20171207053059.19487-2-tiwei.bie@intel.com> <9407e2ce-8b2b-9a9d-a493-1757609184a9@redhat.com> <20171208023034.4f5u3fujmupraaia@debian-xvivbkq> From: Kevin Traynor Organization: Red Hat Message-ID: <180be858-0b4c-8d8c-ef84-3a2931df8cab@redhat.com> Date: Fri, 8 Dec 2017 10:17:22 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.0 MIME-Version: 1.0 In-Reply-To: <20171208023034.4f5u3fujmupraaia@debian-xvivbkq> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Fri, 08 Dec 2017 10:17:29 +0000 (UTC) Subject: Re: [dpdk-stable] [dpdk-dev] [PATCH 1/5] net/virtio: fix vector Rx break caused by rxq flushing X-BeenThere: stable@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches for DPDK stable branches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 08 Dec 2017 10:17:30 -0000 On 12/08/2017 02:30 AM, Tiwei Bie wrote: > On Thu, Dec 07, 2017 at 04:00:57PM +0000, Kevin Traynor wrote: >> On 12/07/2017 05:30 AM, Tiwei Bie wrote: >>> The vector Rx will be broken if backend has consumed all >>> the descs in the avail ring before the device is started. >>> Because in current implementation, vector Rx will return >>> immediately without refilling the avail ring if the used >>> ring is empty. So we have to refill the avail ring after >>> flushing the elements in the used ring for vector Rx. >>> >>> Besides, vector Rx has a different ring layout assumption >>> and mbuf management. So we need to handle it differently. >>> >> >> Hi Tiwei, does the issue only occur with the vector rx? How about if the >> simple rx is used because VIRTIO_NET_F_MRG_RXBUF is set? > > Hi Kevin, > > Yes, you are right! The issue only occurs with the vector > Rx. The vector Rx (i.e. the simple Rx) won't be used if > VIRTIO_NET_F_MRG_RXBUF is set. > > Best regards, > Tiwei Bie > Thanks for clarifying this Tiwei, Kevin.