Pete Heist <p...@heistp.net> writes: > Ok, the lockup goes away if you use no-split-gso on the cake qdiscs for the > default traffic (noted below in the drr and hfsc cases with "!!! must use > no-split-gso here !!!"). Only I’d like my 600 μs back. :) > > This smells of a bug Toke fixed on Sep 12, 2018 in > 42e87f12ea5c390bf5eeb658c942bc810046160a, but then reverted in the next > commit because it was fixed upstream. However, if I re-apply that commit, it > still doesn’t fix it. > > Perhaps there are more cases where skb_reset_mac_len(skb) needs to be called > somewhere for VLAN support? > > I managed to capture some output from what happens to hfsc: > > [ 683.864456] ------------[ cut here ]------------ > [ 683.869116] WARNING: CPU: 1 PID: 11 at net/sched/sch_hfsc.c:1427 > 0xf9ced4ef()
So this seems to be this line: WARN_ON(next_time == 0); See https://elixir.bootlin.com/linux/v3.16.7/source/net/sched/sch_hfsc.c#L1427 Which seems to indicate that HFSC can't find the next class to schedule. Not entirely sure why, nor why this only happens with CAKE as a qdisc. But I don't think it's actually an infinite loop that's causing it... -Toke _______________________________________________ Cake mailing list Cake@lists.bufferbloat.net https://lists.bufferbloat.net/listinfo/cake