From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-130.freemail.mail.aliyun.com (out30-130.freemail.mail.aliyun.com [115.124.30.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D73581A9FB0; Sat, 28 Feb 2026 01:52:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.130 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772243576; cv=none; b=CZ4xxxuCX9qVDPiCpJODXjQNae1+Nf0bc63LlrNWDrVXJ63pxHM0IHa96zTihFdRB4jyueR7W6hD3hxeFuumUQxjw9E1mAXeh9tILvhwAqyCDcmRM5JURWjulU5NAOIcaQjEoEd6bcUfwUdjfTT1+cpRU7OHR9j4v+NaHkhtxi0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772243576; c=relaxed/simple; bh=B2YeU3WjsCqsveIQvxStrCLJ4S5p9Q/sC2ikaUwYSI0=; h=Message-ID:Subject:Date:From:To:Cc:References:In-Reply-To; b=h21/mFlwIbaxsnhU0+niZR9CL3xJmj3a+VQxSYx7KGyh/os29KtLT8tYQ7FCgrzjNnbSnrIdH6qzvdSKx3pwXUBTMEgo3Qdwsnrrbgk5SsrGy+c7V/oztTY73d3hrvDCOMqrgf83e4v50OcdL23vHpQhuPQ7im8n9Le5xfS08jw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=sexU8DDT; arc=none smtp.client-ip=115.124.30.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="sexU8DDT" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1772243567; h=Message-ID:Subject:Date:From:To; bh=W8d6Bh+HP5EteTq+o9ULWf8DeN2EtdjRgF0wir3dN90=; b=sexU8DDTo0zqcgyxJhhmmHjhZgfbUwXRVB3C3hz72LKKeGbncCD5a52SPjBnX4fgxORtgl2XoRN1w0pbC0VymFVXTwz9txUDvlcu4a3beCA5IdQY2Z3SWXJlBqoW8Ry4P0/M84VoCv35jTEQQ+1mZRoTlmrz6KcdhjcV2J/5LvE= Received: from localhost(mailfrom:xuanzhuo@linux.alibaba.com fp:SMTPD_---0WzvnDMh_1772243566 cluster:ay36) by smtp.aliyun-inc.com; Sat, 28 Feb 2026 09:52:46 +0800 Message-ID: <1772243553.11669-1-xuanzhuo@linux.alibaba.com> Subject: Re: [PATCH net-next] virtio-net: xsk: Support wakeup on RX side Date: Sat, 28 Feb 2026 09:52:33 +0800 From: Xuan Zhuo To: Bui Quang Minh Cc: "Michael S. Tsirkin" , Jason Wang , =?utf-8?q?Eugenio_P=C3=A9rez?= , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , virtualization@lists.linux.dev, linux-kernel@vger.kernel.org, Bui Quang Minh , netdev@vger.kernel.org References: <20260227150949.13089-1-minhquangbui99@gmail.com> In-Reply-To: <20260227150949.13089-1-minhquangbui99@gmail.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: On Fri, 27 Feb 2026 22:09:49 +0700, Bui Quang Minh wrote: > When XDP_USE_NEED_WAKEUP is used and the fill ring is empty so no buffer > is allocated on RX side, allow RX NAPI to be descheduled. This avoids > wasting CPU cycles on polling. Users will be notified and they need to > make a wakeup call after refilling the ring. > > Signed-off-by: Bui Quang Minh LGTM Reviewed-by: Xuan Zhuo > --- > drivers/net/virtio_net.c | 38 ++++++++++++++++++++++++++++++-------- > 1 file changed, 30 insertions(+), 8 deletions(-) > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index db88dcaefb20..494acc904b2c 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -1454,8 +1454,19 @@ static int virtnet_add_recvbuf_xsk(struct virtnet_info *vi, struct receive_queue > xsk_buffs = rq->xsk_buffs; > > num = xsk_buff_alloc_batch(pool, xsk_buffs, rq->vq->num_free); > - if (!num) > + if (!num) { > + if (xsk_uses_need_wakeup(pool)) { > + xsk_set_rx_need_wakeup(pool); > + /* Return 0 instead of -ENOMEM so that NAPI is > + * descheduled. > + */ > + return 0; > + } > + > return -ENOMEM; > + } else { > + xsk_clear_rx_need_wakeup(pool); > + } > > len = xsk_pool_get_rx_frame_size(pool) + vi->hdr_len; > > @@ -1588,20 +1599,21 @@ static bool virtnet_xsk_xmit(struct send_queue *sq, struct xsk_buff_pool *pool, > return sent; > } > > -static void xsk_wakeup(struct send_queue *sq) > +static void xsk_wakeup(struct napi_struct *napi, struct virtqueue *vq) > { > - if (napi_if_scheduled_mark_missed(&sq->napi)) > + if (napi_if_scheduled_mark_missed(napi)) > return; > > local_bh_disable(); > - virtqueue_napi_schedule(&sq->napi, sq->vq); > + virtqueue_napi_schedule(napi, vq); > local_bh_enable(); > } > > static int virtnet_xsk_wakeup(struct net_device *dev, u32 qid, u32 flag) > { > struct virtnet_info *vi = netdev_priv(dev); > - struct send_queue *sq; > + struct napi_struct *napi; > + struct virtqueue *vq; > > if (!netif_running(dev)) > return -ENETDOWN; > @@ -1609,9 +1621,19 @@ static int virtnet_xsk_wakeup(struct net_device *dev, u32 qid, u32 flag) > if (qid >= vi->curr_queue_pairs) > return -EINVAL; > > - sq = &vi->sq[qid]; > + if (flag == XDP_WAKEUP_TX) { > + struct send_queue *sq = &vi->sq[qid]; > + > + napi = &sq->napi; > + vq = sq->vq; > + } else { > + struct receive_queue *rq = &vi->rq[qid]; > + > + napi = &rq->napi; > + vq = rq->vq; > + } > > - xsk_wakeup(sq); > + xsk_wakeup(napi, vq); > return 0; > } > > @@ -1623,7 +1645,7 @@ static void virtnet_xsk_completed(struct send_queue *sq, int num) > * wakeup the tx napi to consume the xsk tx queue, because the tx > * interrupt may not be triggered. > */ > - xsk_wakeup(sq); > + xsk_wakeup(&sq->napi, sq->vq); > } > > static int __virtnet_xdp_xmit_one(struct virtnet_info *vi, > -- > 2.43.0 >