On 2016-07-12 21:05, Cong Wang wrote:
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!
It is not easy, because it is NAS with approx 5000 users connected (and
they are constantly connecting/disconnecting), and crash can't be
reproduced easily. If i will remove qdisc/filters users will get
unlimited speed and this will cause serious service degradation.
But maybe i can add some debug lines and run some test kernel if
necessary (if it will not cause serious performance overhead).
