From mboxrd@z Thu Jan 1 00:00:00 1970 From: Willem de Bruijn Subject: [PATCH net-next RFC 1/4] virtio-net: napi helper functions Date: Fri, 3 Mar 2017 09:39:06 -0500 Message-ID: <20170303143909.80001-2-willemdebruijn.kernel@gmail.com> References: <20170303143909.80001-1-willemdebruijn.kernel@gmail.com> Cc: jasowang@redhat.com, mst@redhat.com, Willem de Bruijn To: netdev@vger.kernel.org Return-path: Received: from mail-qk0-f195.google.com ([209.85.220.195]:35770 "EHLO mail-qk0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751637AbdCCOpo (ORCPT ); Fri, 3 Mar 2017 09:45:44 -0500 Received: by mail-qk0-f195.google.com with SMTP id n127so27523010qkf.2 for ; Fri, 03 Mar 2017 06:45:42 -0800 (PST) In-Reply-To: <20170303143909.80001-1-willemdebruijn.kernel@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Willem de Bruijn Prepare virtio-net for tx napi by converting existing napi code to use helper functions. This also deduplicates some logic. Signed-off-by: Willem de Bruijn --- drivers/net/virtio_net.c | 65 ++++++++++++++++++++++++++---------------------- 1 file changed, 35 insertions(+), 30 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index bf95016f442a..8c21e9a4adc7 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -239,6 +239,26 @@ static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask) return p; } +static void virtqueue_napi_schedule(struct napi_struct *napi, + struct virtqueue *vq) +{ + if (napi_schedule_prep(napi)) { + virtqueue_disable_cb(vq); + __napi_schedule(napi); + } +} + +static void virtqueue_napi_complete(struct napi_struct *napi, + struct virtqueue *vq, int processed) +{ + int opaque; + + opaque = virtqueue_enable_cb_prepare(vq); + if (napi_complete_done(napi, processed) && + unlikely(virtqueue_poll(vq, opaque))) + virtqueue_napi_schedule(napi, vq); +} + static void skb_xmit_done(struct virtqueue *vq) { struct virtnet_info *vi = vq->vdev->priv; @@ -936,27 +956,20 @@ static void skb_recv_done(struct virtqueue *rvq) struct virtnet_info *vi = rvq->vdev->priv; struct receive_queue *rq = &vi->rq[vq2rxq(rvq)]; - /* Schedule NAPI, Suppress further interrupts if successful. */ - if (napi_schedule_prep(&rq->napi)) { - virtqueue_disable_cb(rvq); - __napi_schedule(&rq->napi); - } + virtqueue_napi_schedule(&rq->napi, rvq); } -static void virtnet_napi_enable(struct receive_queue *rq) +static void virtnet_napi_enable(struct virtqueue *vq, struct napi_struct *napi) { - napi_enable(&rq->napi); + napi_enable(napi); /* If all buffers were filled by other side before we napi_enabled, we - * won't get another interrupt, so process any outstanding packets - * now. virtnet_poll wants re-enable the queue, so we disable here. - * We synchronize against interrupts via NAPI_STATE_SCHED */ - if (napi_schedule_prep(&rq->napi)) { - virtqueue_disable_cb(rq->vq); - local_bh_disable(); - __napi_schedule(&rq->napi); - local_bh_enable(); - } + * won't get another interrupt, so process any outstanding packets now. + * Call local_bh_enable after to trigger softIRQ processing. + */ + local_bh_disable(); + virtqueue_napi_schedule(napi, vq); + local_bh_enable(); } static void refill_work(struct work_struct *work) @@ -971,7 +984,7 @@ static void refill_work(struct work_struct *work) napi_disable(&rq->napi); still_empty = !try_fill_recv(vi, rq, GFP_KERNEL); - virtnet_napi_enable(rq); + virtnet_napi_enable(rq->vq, &rq->napi); /* In theory, this can happen: if we don't get any buffers in * we will *never* try to fill again. @@ -1011,21 +1024,13 @@ static int virtnet_poll(struct napi_struct *napi, int budget) { struct receive_queue *rq = container_of(napi, struct receive_queue, napi); - unsigned int r, received; + unsigned int received; received = virtnet_receive(rq, budget); /* Out of packets? */ - if (received < budget) { - r = virtqueue_enable_cb_prepare(rq->vq); - if (napi_complete_done(napi, received)) { - if (unlikely(virtqueue_poll(rq->vq, r)) && - napi_schedule_prep(napi)) { - virtqueue_disable_cb(rq->vq); - __napi_schedule(napi); - } - } - } + if (received < budget) + virtqueue_napi_complete(napi, rq->vq, received); return received; } @@ -1040,7 +1045,7 @@ static int virtnet_open(struct net_device *dev) /* Make sure we have some buffers: if oom use wq. */ if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL)) schedule_delayed_work(&vi->refill, 0); - virtnet_napi_enable(&vi->rq[i]); + virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi); } return 0; @@ -1737,7 +1742,7 @@ static int virtnet_restore_up(struct virtio_device *vdev) schedule_delayed_work(&vi->refill, 0); for (i = 0; i < vi->max_queue_pairs; i++) - virtnet_napi_enable(&vi->rq[i]); + virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi); } netif_device_attach(vi->dev); -- 2.12.0.rc1.440.g5b76565f74-goog