On Wed, May 15, 2013 at 12:00:03PM +0100, Nicholas Thomas wrote: > Hi again, > > On Tue, 2013-05-14 at 15:49 +0100, Nicholas Thomas wrote: > > /sys/devices/virtual/net/t100/tun_flags is 0x5002 - so it looks like > > IFF_ONE_QUEUE was indeed unset by qemu (which is lacking the patch). It > > surprises me, but that's probably my fault, rather than qemu's. > > > I've rebuilt 1.4.1 with the IFF_ONE_QUEUE patch and tun_flags is now > 0x7002; unfortunately, I'm still seeing this bug, twice in five trials. > Symptoms in `ifconfig t100` now differ; overruns stays at 0, and > "dropped" increases monotonically as I send packets. Those packets do > appear if I tcpdump t100 on the host, but not if I tcpdump t100 on the > guest. > > I've turned off gro in the guest, which makes no difference, and tried > changing the queue sizes (post-hoc) in both guest and host, in the hope > of causing them to be emptied out, clearing the condition; again to no > effect. > > The VMs in question are bridged to a large (and busy) VLAN with no > ingress filtering to speak of; I guess what's happening is that the > transmit queue is filled up by that traffic while the guest is in ipxe, > and it never gets out of that state when it happens... so maybe there is > still an underlying problem? > > /Nick
Is this with or without vhost-net in host? -- MST
