> -----Original Message----- > From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Huawei at dpdk.org > Sent: Friday, December 11, 2015 12:08 AM > To: dev at dpdk.org > Subject: [dpdk-dev] [PATCH] virtio: fix virtio_net_hdr desc pointing to the > same buffer > > The virtio_net_hdr desc all pointed to the same buffer. It doesn't cause > issue because in the simple TX mode we don't use the header. This patch > makes the header desc point to different buffer. > > Signed-off-by: Huawei Xie <huawei.xie at intel.com> > --- > drivers/net/virtio/virtio_rxtx.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/net/virtio/virtio_rxtx.c > b/drivers/net/virtio/virtio_rxtx.c > index 74b39ef..6cfd315 100644 > --- a/drivers/net/virtio/virtio_rxtx.c > +++ b/drivers/net/virtio/virtio_rxtx.c > @@ -352,7 +352,7 @@ virtio_dev_vring_start(struct virtqueue *vq, int > queue_type) > vq->vq_ring.desc[i + mid_idx].next = i; > vq->vq_ring.desc[i + mid_idx].addr = > vq->virtio_net_hdr_mem + > - mid_idx * vq->hw- > >vtnet_hdr_size; > + i * vq->hw->vtnet_hdr_size; > vq->vq_ring.desc[i + mid_idx].len = > vq->hw->vtnet_hdr_size; > vq->vq_ring.desc[i + mid_idx].flags = > -- > 1.8.1.4
So in the case when header is not used, shall the way of pointing to all header bufs to one buf help improve the performance? At least, it saves some of cache lines. Thanks, Jianfeng
