Re: Interrupt storm

[Dima Veselov <kab00m%lich.phys.spbu.ru@localhost>]

On Thu, Oct 25, 2018 at 12:42:52PM -0400, Christos Zoulas wrote:
> | On Wed, Oct 24, 2018 at 06:01:53PM +0000, Christos Zoulas wrote:
> | > >> 
> | > >> I have two identical Dell R220 servers running NetBSD 8-STABLE
> | > >> and they are working fine, but I noticed permanent high CPU
> | > >> usage.
> | > >> 
> | > >> I think this is kind of a driver problem, but how can I identify
> | > >> which hardware cause that load?
> | > 
> | > If you switch to the "threads" display by typing "t" you'll see the thread
> | > that is using all the cpu. My guess is it is "ioflush".
> | 
> | No, it is sysmon. Everything down those 3 take 0%.
>
> Ok, I lose :-) So it must be some driver looping in sysmon events...
> 
> Perhaps you can use:
> 
> # crash
> crash> ps

I beleive these are ACPI calls.

crash> t /a fffffe825ddb84a0
trace: pid 0 lid 15 at 0xffff8000abb3af90
sleepq_block() at sleepq_block+0x97
AcpiEvFinishGpe() at AcpiEvFinishGpe+0x17
AcpiEvAsynchEnableGpe() at AcpiEvAsynchEnableGpe+0x21
sysmon_task_queue_thread() at sysmon_task_queue_thread+0x5d

crash> t /a fffffe825ddb84a0
trace: pid 0 lid 15 at 0xffffffff8023ebed
_KERNEL_OPT_ACPI_SCANPCI() at _KERNEL_OPT_ACPI_SCANPCI+0x7

crash> t /a fffffe825ddb84a0
trace: pid 0 lid 15 at 0xffff8000abb3afb0
mptramp_longmode() at mptramp_longmode+0x1f1c

crash> t /a fffffe825ddb84a0
trace: pid 0 lid 15 at 0xffff8000abb3af90
sleepq_block() at sleepq_block+0x97
cv_wait() at cv_wait+0x9e
sysmon_task_queue_thread() at sysmon_task_queue_thread+0x9a

-- 
Sincerely yours,
Dima Veselov
Physics R&D Establishment of Saint-Petersburg University