From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dor Laor Subject: [PATCH] Increase the tx queue to 512 descriptors to fix performance problem. Date: Wed, 09 Jan 2008 15:23:36 +0200 Message-ID: <1199885016.4382.22.camel@localhost.localdomain> Reply-To: dor.laor-atKUWr5tajBWk0Htik3J/w@public.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: kvm-devel , Anthony Liguori , Rusty Russell , "virtualization-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org Now that we have a host timer based tx wakeup it waits for 64 packets or timeout before processing them. This might cause the guest to run out of tx buffers while the host holds them up. This is a temporal solution to quickly bring back performance to 800mbps. But a better fix will soon be sent (its not the only problem). Signed-off-by: Dor Laor --- qemu/hw/virtio-net.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/qemu/hw/virtio-net.c b/qemu/hw/virtio-net.c index 777fe2c..3d07b65 100644 --- a/qemu/hw/virtio-net.c +++ b/qemu/hw/virtio-net.c @@ -293,7 +293,7 @@ void *virtio_net_init(PCIBus *bus, NICInfo *nd, int devfn) n->vdev.update_config = virtio_net_update_config; n->vdev.get_features = virtio_net_get_features; n->rx_vq = virtio_add_queue(&n->vdev, 512, virtio_net_handle_rx); - n->tx_vq = virtio_add_queue(&n->vdev, 128, virtio_net_handle_tx); + n->tx_vq = virtio_add_queue(&n->vdev, 512, virtio_net_handle_tx); n->can_receive = 0; memcpy(n->mac, nd->macaddr, 6); n->vc = qemu_new_vlan_client(nd->vlan, virtio_net_receive, -- 1.5.3.7 ------------------------------------------------------------------------- Check out the new SourceForge.net Marketplace. It's the best place to buy or sell services for just about anything Open Source. http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace