On 15/02/13 15:27, Peter Lieven wrote: > > Am 15.02.2013 um 14:32 schrieb Stefan Hajnoczi <stefa...@gmail.com>: > >> 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 > > i know. is qemu really using it on MACs? >
It has nothing todo with Apple products. Its about a linux kernel driver that provides a tap like interface that can be attached to an network interface with MAC-address filtering. http://virt.kernelnewbies.org/MacVTap Christian
