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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 76812C43334 for ; Fri, 15 Jul 2022 08:37:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232804AbiGOIhL (ORCPT ); Fri, 15 Jul 2022 04:37:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58884 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231569AbiGOIhJ (ORCPT ); Fri, 15 Jul 2022 04:37:09 -0400 Received: from out30-45.freemail.mail.aliyun.com (out30-45.freemail.mail.aliyun.com [115.124.30.45]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0877781491; Fri, 15 Jul 2022 01:37:06 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R121e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04400;MF=xuanzhuo@linux.alibaba.com;NM=1;PH=DS;RN=36;SR=0;TI=SMTPD_---0VJOcj-v_1657874219; Received: from localhost(mailfrom:xuanzhuo@linux.alibaba.com fp:SMTPD_---0VJOcj-v_1657874219) by smtp.aliyun-inc.com; Fri, 15 Jul 2022 16:37:00 +0800 Message-ID: <1657874178.9766078-2-xuanzhuo@linux.alibaba.com> Subject: Re: [PATCH v11 38/40] virtio_net: support rx queue resize Date: Fri, 15 Jul 2022 16:36:18 +0800 From: Xuan Zhuo To: Jason Wang Cc: Richard Weinberger , Anton Ivanov , Johannes Berg , "Michael S. Tsirkin" , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Hans de Goede , Mark Gross , Vadim Pasternak , Bjorn Andersson , Mathieu Poirier , Cornelia Huck , Halil Pasic , Eric Farman , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Alexei Starovoitov , Daniel Borkmann , Jesper Dangaard Brouer , John Fastabend , Vincent Whitchurch , linux-um@lists.infradead.org, netdev , platform-driver-x86@vger.kernel.org, linux-remoteproc@vger.kernel.org, linux-s390@vger.kernel.org, kvm , "open list:XDP (eXpress Data Path)" , kangjie.xu@linux.alibaba.com, virtualization References: <20220629065656.54420-1-xuanzhuo@linux.alibaba.com> <20220629065656.54420-39-xuanzhuo@linux.alibaba.com> <1656986375.3420787-1-xuanzhuo@linux.alibaba.com> In-Reply-To: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-s390@vger.kernel.org On Fri, 8 Jul 2022 14:20:52 +0800, Jason Wang wrote: > On Tue, Jul 5, 2022 at 10:00 AM Xuan Zhuo wr= ote: > > > > On Mon, 4 Jul 2022 11:44:12 +0800, Jason Wang wro= te: > > > > > > =E5=9C=A8 2022/6/29 14:56, Xuan Zhuo =E5=86=99=E9=81=93: > > > > This patch implements the resize function of the rx queues. > > > > Based on this function, it is possible to modify the ring num of the > > > > queue. > > > > > > > > Signed-off-by: Xuan Zhuo > > > > --- > > > > drivers/net/virtio_net.c | 22 ++++++++++++++++++++++ > > > > 1 file changed, 22 insertions(+) > > > > > > > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > > > > index 9fe222a3663a..6ab16fd193e5 100644 > > > > --- a/drivers/net/virtio_net.c > > > > +++ b/drivers/net/virtio_net.c > > > > @@ -278,6 +278,8 @@ struct padded_vnet_hdr { > > > > char padding[12]; > > > > }; > > > > > > > > +static void virtnet_rq_free_unused_buf(struct virtqueue *vq, void = *buf); > > > > + > > > > static bool is_xdp_frame(void *ptr) > > > > { > > > > return (unsigned long)ptr & VIRTIO_XDP_FLAG; > > > > @@ -1846,6 +1848,26 @@ static netdev_tx_t start_xmit(struct sk_buff= *skb, struct net_device *dev) > > > > return NETDEV_TX_OK; > > > > } > > > > > > > > +static int virtnet_rx_resize(struct virtnet_info *vi, > > > > + struct receive_queue *rq, u32 ring_num) > > > > +{ > > > > + int err, qindex; > > > > + > > > > + qindex =3D rq - vi->rq; > > > > + > > > > + napi_disable(&rq->napi); > > > > > > > > > Do we need to cancel the refill work here? > > > > > > I think no, napi_disable is mutually exclusive, which ensures that ther= e will be > > no conflicts between them. > > So this sounds similar to what I've fixed recently. > > 1) NAPI schedule delayed work. > 2) we disable NAPI here > 3) delayed work get schedule and call NAPI again > > ? Yes, but I don't think there are any negative effects. Thanks. > > Thanks > > > > > Thanks. > > > > > > > > Thanks > > > > > > > > > > + > > > > + err =3D virtqueue_resize(rq->vq, ring_num, virtnet_rq_free_unus= ed_buf); > > > > + if (err) > > > > + netdev_err(vi->dev, "resize rx fail: rx queue index: %d= err: %d\n", qindex, err); > > > > + > > > > + if (!try_fill_recv(vi, rq, GFP_KERNEL)) > > > > + schedule_delayed_work(&vi->refill, 0); > > > > + > > > > + virtnet_napi_enable(rq->vq, &rq->napi); > > > > + return err; > > > > +} > > > > + > > > > /* > > > > * Send command via the control virtqueue and check status. Comm= ands > > > > * supported by the hypervisor, as indicated by feature bits, sho= uld > > > > > >