On Monday, September 17, 2012 11:49:59 am Ryan Stone wrote: > I know that there have been a lot of discussions about fixing how > packets are handed off to ifnets due to the current methods being > extremely race-prone. Has there been any consensus on how the problem > is going to be solved? > > In my particular case, I've seen an if_bridge interface whose if_snd > queue is full, and once an ifnet reaches that point it will never > transmit anything ever again unless its driver manually calls the > start method somehow. > > As a short-term fix I'm temped to call to if_start in IFQ_HANDOFF_ADJ > even if IFQ_ENQUEUE returns an error, to ensure that the queue will be > drained eventually, but I'm wondering if people are actively working > on longer-term fixes.
I think for if_bridge the fix is that it no longer uses if_start. :) For real hardware you will get some sort of TX completion interrupt that will restart the transmit queue. Virtual software-only interfaces such as vlan(4) and if_bridge(4) don't have that luxury though, and the best bet for them is to probably have them use if_transmit instead. vlan(4) and if_bridge(4) are already fixed for that (if_bridge was only fixed a week or so ago in HEAD). -- John Baldwin _______________________________________________ freebsd-net@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org"
