On Fri, Feb 15, 2013 at 10:32:31AM +0100, Peter Lieven wrote: > historically the kernel queues packets two times. once > at the device and second in qdisc. this is believed to cause > interface stalls if one of these queues overruns. > > setting IFF_ONE_QUEUE is the default in kernels >= 3.8. the > flag is ignored since then. see kernel commit > 5d097109257c03a71845729f8db6b5770c4bbedc > > v2: > - do only set the flag on linux as it breaks macvtap > - define IFF_ONE_QUEUE in tap-linux.h > > Signed-off-by: Peter Lieven <p...@kamp.de> > --- > net/tap-linux.c | 4 ++++ > net/tap-linux.h | 1 + > 2 files changed, 5 insertions(+) > > diff --git a/net/tap-linux.c b/net/tap-linux.c > index a953189..d49f2fd 100644 > --- a/net/tap-linux.c > +++ b/net/tap-linux.c > @@ -51,6 +51,10 @@ int tap_open(char *ifname, int ifname_size, int *vnet_hdr, > memset(&ifr, 0, sizeof(ifr)); > ifr.ifr_flags = IFF_TAP | IFF_NO_PI; > > +#ifdef __linux__ > + ifr.ifr_flags |= IFF_ONE_QUEUE; > +#endif
tap-linux.c <--- notice the filename Perhaps the solution is to try with IFF_ONE_QUEUE. If the result is -EINVAL, try without. Stefan
