mlx4en, timer irq @100%...

[Hans Petter Selasky]

On 08/07/17 19:19, Ben RUBSON wrote:
> 
>> On 07 Aug 2017, at 18:19, Matt Joras <mjoras at FreeBSD.org> wrote:
>>
>> On 08/07/2017 09:11, Hans Petter Selasky wrote:
>>> Hi,
>>>
>>> Try to enter "kgdb" and run:
>>>
>>> thread apply all bt
>>>
>>> Look for the callout function in question.
>>>
>>> --HPS
>>>
>> If you don't have a way to attach kgdb handy you could also break into
>> ddb(4) and run "alltrace". Though gdb would be more useful for an
>> ongoing session if we need more than the backtrace since you could
>> switch to that thread and investigate it directly.
>>
> 
> Hi Hans & Matt,
> 
> Thank you for your answers, glad to hear from you :)
> 
> So here is the full kgdb(thread apply all bt) command log :
> https://benrubson.github.io/kgdb.log
> 
> We found the faulty thread :
> 
> # procstat -ak | grep "swi4.*tcp"
>     12 100029 intr             swi4: clock (0)  tcp_tw_2msl_scan pfslowtimo softclock_call_cc softclock intr_event_execute_handlers ithread_loop fork_exit fork_trampoline
> 
> # kgdb
> (...)
> Thread 747 (Thread 100029):
> #0  sched_switch (td=0xfffff8000f337500, newtd=0xfffff8010e144000, flags=<value optimized out>) at /usr/src/sys/kern/sched_ule.c:1973
> #1  0xfffffe1000f92d80 in ?? ()
> #2  0xfffffe0f8f74b6e0 in ?? ()
> #3  0xffffffff810bd274 in handleevents (now=<value optimized out>, fake=Error accessing memory address 0xffffffffffffffcc: Bad address.
> ) at /usr/src/sys/kern/kern_clocksource.c:223
> Previous frame inner to this frame (corrupt stack?)
> (...)
> 
> Of course let me know if you need further info.
> 

Can you try to dump "td":

set print pretty on
thread 747
frame 0
print *td

It might give some more clues.

--HPS