From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by dpdk.org (Postfix) with ESMTP id E1BA4F04 for ; Fri, 21 Sep 2018 14:28:11 +0200 (CEST) X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 21 Sep 2018 05:28:10 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.54,285,1534834800"; d="scan'208";a="85448432" Received: from btwcube1.sh.intel.com (HELO debian) ([10.67.104.151]) by orsmga003.jf.intel.com with ESMTP; 21 Sep 2018 05:28:03 -0700 Date: Fri, 21 Sep 2018 20:26:58 +0800 From: Tiwei Bie To: Jens Freimann Cc: dev@dpdk.org, maxime.coquelin@redhat.com, Gavin.Hu@arm.com, zhihong.wang@intel.com Message-ID: <20180921122658.GA24906@debian> References: <20180921103308.16357-1-jfreimann@redhat.com> <20180921103308.16357-7-jfreimann@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20180921103308.16357-7-jfreimann@redhat.com> User-Agent: Mutt/1.10.1 (2018-07-13) Subject: Re: [dpdk-dev] [PATCH v6 06/11] net/virtio: implement transmit path for packed queues X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 21 Sep 2018 12:28:12 -0000 On Fri, Sep 21, 2018 at 12:33:03PM +0200, Jens Freimann wrote: [...] > > static inline int > -desc_is_used(struct vring_desc_packed *desc, struct vring *vr) > +_desc_is_used(struct vring_desc_packed *desc) > { > uint16_t used, avail; > > used = !!(desc->flags & VRING_DESC_F_USED(1)); > avail = !!(desc->flags & VRING_DESC_F_AVAIL(1)); > > - return used == avail && used == vr->used_wrap_counter; > + return used == avail; > + > +} > + > +static inline int > +desc_is_used(struct vring_desc_packed *desc, struct vring *vr) > +{ > + uint16_t used; > + > + used = !!(desc->flags & VRING_DESC_F_USED(1)); > + > + return _desc_is_used(desc) && used == vr->used_wrap_counter; > } > > /* The standard layout for the ring is a continuous chunk of memory which > diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c > index eb891433e..ea6300563 100644 > --- a/drivers/net/virtio/virtio_rxtx.c > +++ b/drivers/net/virtio/virtio_rxtx.c > @@ -38,6 +38,7 @@ > #define VIRTIO_DUMP_PACKET(m, len) do { } while (0) > #endif > > + > int > virtio_dev_rx_queue_done(void *rxq, uint16_t offset) > { > @@ -165,6 +166,31 @@ virtqueue_dequeue_rx_inorder(struct virtqueue *vq, > #endif > > /* Cleanup from completed transmits. */ > +static void > +virtio_xmit_cleanup_packed(struct virtqueue *vq) > +{ > + uint16_t idx; > + uint16_t size = vq->vq_nentries; > + struct vring_desc_packed *desc = vq->vq_ring.desc_packed; > + struct vq_desc_extra *dxp; > + > + idx = vq->vq_used_cons_idx; > + while (_desc_is_used(&desc[idx]) && We can't just compare the AVAIL bit and USED bit to check whether a desc is used. > + vq->vq_free_cnt < size) { > + dxp = &vq->vq_descx[idx]; The code is still assuming the descs will be written back by device in order. The vq->vq_descx[] needs to be managed e.g. as a list to support the out-of-order processing. IOW, we can't assume vq->vq_descx[idx] is corresponding to desc[idx] when device may write back the descs out of order. > + vq->vq_free_cnt += dxp->ndescs; > + idx += dxp->ndescs; > + idx = idx >= size ? idx - size : idx; > + if (idx == 0) { > + vq->vq_ring.used_wrap_counter ^= 1; > + } > + if (dxp->cookie != NULL) { > + rte_pktmbuf_free(dxp->cookie); > + dxp->cookie = NULL; > + } > + } > +} [...]