From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [PATCH net] vhost_net: don't continue to call the recvmsg when meet errors Date: Wed, 30 Nov 2016 15:40:51 +0200 Message-ID: <20161130152004-mutt-send-email-mst@kernel.org> References: <1480507857-22976-1-git-send-email-wangyunjian@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: jasowang@redhat.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, caihe@huawei.com To: Yunjian Wang Return-path: Received: from mx1.redhat.com ([209.132.183.28]:60644 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753106AbcK3Nk4 (ORCPT ); Wed, 30 Nov 2016 08:40:56 -0500 Content-Disposition: inline In-Reply-To: <1480507857-22976-1-git-send-email-wangyunjian@huawei.com> Sender: netdev-owner@vger.kernel.org List-ID: On Wed, Nov 30, 2016 at 08:10:57PM +0800, Yunjian Wang wrote: > When we meet an error(err=-EBADFD) recvmsg, How do you get EBADFD? Won't vhost_net_rx_peek_head_len return 0 in this case, breaking the loop? > the error handling in vhost > handle_rx() will continue. This will cause a soft CPU lockup in vhost thread. > > Signed-off-by: Yunjian Wang > --- > drivers/vhost/net.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c > index 5dc128a..edc470b 100644 > --- a/drivers/vhost/net.c > +++ b/drivers/vhost/net.c > @@ -717,6 +717,9 @@ static void handle_rx(struct vhost_net *net) > pr_debug("Discarded rx packet: " > " len %d, expected %zd\n", err, sock_len); > vhost_discard_vq_desc(vq, headcount); > + /* Don't continue to do, when meet errors. */ > + if (err < 0) > + goto out; You might get e.g. EAGAIN and I think you need to retry in this case. > continue; > } > /* Supply virtio_net_hdr if VHOST_NET_F_VIRTIO_NET_HDR */ > -- > 1.9.5.msysgit.1 >