From 7b21e34fd1c272e3a8c3846168f2f6287a4cd72b Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Thu, 12 Jan 2012 15:44:42 +1030 Subject: virtio: harsher barriers for rpmsg. We were cheating with our barriers; using the smp ones rather than the real device ones. That was fine, until rpmsg came along, which is used to talk to a real device (a non-SMP CPU). Unfortunately, just putting back the real barriers (reverting d57ed95d) causes a performance regression on virtio-pci. In particular, Amos reports netbench's TCP_RR over virtio_net CPU utilization increased up to 35% while throughput went down by up to 14%. By comparison, this branch is in the noise. Reference: https://lkml.org/lkml/2011/12/11/22 Signed-off-by: Rusty Russell --- drivers/virtio/virtio_pci.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/virtio/virtio_pci.c') diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c index baabb7937ec..688b42d28da 100644 --- a/drivers/virtio/virtio_pci.c +++ b/drivers/virtio/virtio_pci.c @@ -414,8 +414,8 @@ static struct virtqueue *setup_vq(struct virtio_device *vdev, unsigned index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN); /* create the vring */ - vq = vring_new_virtqueue(info->num, VIRTIO_PCI_VRING_ALIGN, - vdev, info->queue, vp_notify, callback, name); + vq = vring_new_virtqueue(info->num, VIRTIO_PCI_VRING_ALIGN, vdev, + true, info->queue, vp_notify, callback, name); if (!vq) { err = -ENOMEM; goto out_activate_queue; -- cgit v1.2.3-70-g09d2