On 5/30/19 10:39 PM, Karl Johnson wrote:
> Hello,
>
> It's always related to swapper and ksoftirqd:
"swapper" is idle thread, it is called if CPU does not have any active tasks
it would be interesting to look at state of "ksoftirqd" processes several
times, to see any changes.
In provided example I see that this process was captured during processing of
top-level function handles soft interrupts:
do_softirq()-> call_softirq(). Usually these function handles network packets
and I expected your example will contain more deep calltraces.
Probably this happen next time.
Anyway, these calltraces shows that CPUs are NOT 100% busy by processing of
timer interrupts,
so in general the situation looks like expected: in current theory ksoftirq
processes handles network traffic.
Thank you,
Vasily Averin
> Some examples here: https://pastebin.com/wn0nCwce
>
> Karl
>
> On Thu, May 30, 2019 at 3:11 PM Vasily Averin <v...@virtuozzo.com
> <mailto:v...@virtuozzo.com>> wrote:
>
> Dear Karl,
> thank you for reporting the problem.
>
> no, it is not known issue.
> moreover, I doubt it is related to real hardware interrupts,
> soft-interrupts handles delayed procedures like processing of network
> packets.
>
> For troubleshooting is to look at stack of affected running processes via
> /proc/<pid>/stack
> alternatively you can use magic sysrq key
> # echo l > /proc/sysrq-trigger
> it should dump current state of all running processors.
> you can do it few times to monitor state of affected processes.
>
> Thank you,
> Vasily Averin
>
>
> On 5/30/19 7:54 PM, Karl Johnson wrote:
> > Hello,
> >
> > I've upgraded from 2.6.32-042stab133.2 to 2.6.32-042stab138.1 and since
> boot, 2 cores are using 100% cpu on ksoftirqd:
> >
> > root 21 99.9 0.0 0 0 ? R May29 1178:07 \_
> [ksoftirqd/4]
> > root 25 99.9 0.0 0 0 ? R May29 1177:51 \_
> [ksoftirqd/5]
> >
> > From /proc/interrupts I can see that it's caused by IR-IO-APIC-edge
> timer:
> >
> > CPU0 CPU1 CPU2 CPU3 CPU4 CPU5
> CPU6 CPU7
> > 0: 136922 103603 26928 27528 112318229 71888343
> 73755 285735 IR-IO-APIC-edge timer
> >
> > kernel /vmlinuz-2.6.32-042stab138.1 ro
> root=UUID=7367aa0f-8216-44ca-9cc4-affed22bbd9c rd_NO_LUKS rd_NO_LVM
> LANG=en_US.UTF-8 rd_NO_MD SYSFONT=latarcyrheb-sun16 crashkernel=auto
> KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM nohz=off nopti
> >
> > Any way to troubleshoot this? Is it a known issue?
> >
> > Karl
> >
> >
> > _______________________________________________
> > Users mailing list
> > Users@openvz.org <mailto:Users@openvz.org>
> > https://lists.openvz.org/mailman/listinfo/users
> >
>
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