On Tue, Jul 12, 2016 at 11:03 AM, <nuclear...@nuclearcat.com> wrote: > On 2016-07-12 20:31, Cong Wang wrote: >> >> On Mon, Jul 11, 2016 at 12:45 PM, <nuclear...@nuclearcat.com> wrote: >>> >>> Hi >>> >>> On latest kernel i noticed kernel panic happening 1-2 times per day. It >>> is >>> also happening on older kernel (at least 4.5.3). >>> >> ... >>> >>> [42916.426463] Call Trace: >>> [42916.426658] <IRQ> >>> >>> [42916.426719] [<ffffffff81843786>] skb_push+0x36/0x37 >>> [42916.427111] [<ffffffffa00e8ce5>] ppp_start_xmit+0x10f/0x150 >>> [ppp_generic] >>> [42916.427314] [<ffffffff81853467>] dev_hard_start_xmit+0x25a/0x2d3 >>> [42916.427516] [<ffffffff818530f2>] ? >>> validate_xmit_skb.isra.107.part.108+0x11d/0x238 >>> [42916.427858] [<ffffffff8186dee3>] sch_direct_xmit+0x89/0x1b5 >>> [42916.428060] [<ffffffff8186e142>] __qdisc_run+0x133/0x170 >>> [42916.428261] [<ffffffff81850034>] net_tx_action+0xe3/0x148 >>> [42916.428462] [<ffffffff810c401a>] __do_softirq+0xb9/0x1a9 >>> [42916.428663] [<ffffffff810c4251>] irq_exit+0x37/0x7c >>> [42916.428862] [<ffffffff8102b8f7>] smp_apic_timer_interrupt+0x3d/0x48 >>> [42916.429063] [<ffffffff818cb15c>] apic_timer_interrupt+0x7c/0x90 >> >> >> Interesting, we call a skb_cow_head() before skb_push() in >> ppp_start_xmit(), >> I have no idea why this could happen. >> >> Do you have any tc qdisc, filter or actions on this ppp device? > > Yes, i have policing filters for incoming traffic (ingress), and also on > egress htb + pfifo + filters.
Does it make any difference if you remove the egress qdisc and/or filters? If yes, please share the `tc qd show...` and `tc filter show ...`? Thanks!
