From patchwork Wed Dec 23 14:47:36 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: wangyunjian X-Patchwork-Id: 352259 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham 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 78060C433E0 for ; Wed, 23 Dec 2020 14:48:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 308D92333B for ; Wed, 23 Dec 2020 14:48:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728259AbgLWOsb (ORCPT ); Wed, 23 Dec 2020 09:48:31 -0500 Received: from szxga04-in.huawei.com ([45.249.212.190]:9641 "EHLO szxga04-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728251AbgLWOsb (ORCPT ); Wed, 23 Dec 2020 09:48:31 -0500 Received: from DGGEMS409-HUB.china.huawei.com (unknown [172.30.72.58]) by szxga04-in.huawei.com (SkyGuard) with ESMTP id 4D1GJ50r8Hz15hxZ; Wed, 23 Dec 2020 22:47:01 +0800 (CST) Received: from localhost (10.174.243.127) by DGGEMS409-HUB.china.huawei.com (10.3.19.209) with Microsoft SMTP Server id 14.3.498.0; Wed, 23 Dec 2020 22:47:37 +0800 From: wangyunjian To: , , , CC: , , , , , Yunjian Wang Subject: [PATCH net v3 2/2] vhost_net: fix tx queue stuck when sendmsg fails Date: Wed, 23 Dec 2020 22:47:36 +0800 Message-ID: <1608734856-12516-1-git-send-email-wangyunjian@huawei.com> X-Mailer: git-send-email 1.9.5.msysgit.1 MIME-Version: 1.0 X-Originating-IP: [10.174.243.127] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Yunjian Wang Currently the driver don't drop a packet which can't be send by tun (e.g bad packet). In this case, the driver will always process the same packet lead to the tx queue stuck. To fix this issue: 1. in the case of persistent failure (e.g bad packet), the driver can skip this descriptior by ignoring the error. 2. in the case of transient failure (e.g -EAGAIN and -ENOMEM), the driver schedules the worker to try again. Signed-off-by: Yunjian Wang --- drivers/vhost/net.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index c8784dfafdd7..e49dd64d086a 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -827,9 +827,8 @@ static void handle_tx_copy(struct vhost_net *net, struct socket *sock) msg.msg_flags &= ~MSG_MORE; } - /* TODO: Check specific error and bomb out unless ENOBUFS? */ err = sock->ops->sendmsg(sock, &msg, len); - if (unlikely(err < 0)) { + if (unlikely(err == -EAGAIN || err == -ENOMEM)) { vhost_discard_vq_desc(vq, 1); vhost_net_enable_vq(net, vq); break; @@ -922,7 +921,6 @@ static void handle_tx_zerocopy(struct vhost_net *net, struct socket *sock) msg.msg_flags &= ~MSG_MORE; } - /* TODO: Check specific error and bomb out unless ENOBUFS? */ err = sock->ops->sendmsg(sock, &msg, len); if (unlikely(err < 0)) { if (zcopy_used) { @@ -931,9 +929,11 @@ static void handle_tx_zerocopy(struct vhost_net *net, struct socket *sock) nvq->upend_idx = ((unsigned)nvq->upend_idx - 1) % UIO_MAXIOV; } - vhost_discard_vq_desc(vq, 1); - vhost_net_enable_vq(net, vq); - break; + if (err == -EAGAIN || err == -ENOMEM) { + vhost_discard_vq_desc(vq, 1); + vhost_net_enable_vq(net, vq); + break; + } } if (err != len) pr_debug("Truncated TX packet: "