[OpenAFS] OpenAFS client softlockup on highly concurrential file-system patterns (100% CPU in kernel mode)

Ciprian Dorin Craciun ciprian.craciun@gmail.com
Tue, 19 Nov 2019 17:10:40 +0200


On Tue, Nov 19, 2019 at 5:06 PM Mark Vitale <mvitale@sinenomine.net> wrote:
> If you had a true soft lockup, there should be some information in the syslog.

I don't think it was a "softlokup" as per Linux kernel terminology, as
it would have been detected by the kernel.  (But still it took all my
cores to 100% in kernel space as mentioned.)


> If you don't see anything there, you could try this while the hang is occurring:

There wasn't anything in either `journald` (i.e. the syslog
replacement) nor in `dmesg`.  (And the system was freshly rebooted
after each occurrence.)


> # echo t > /proc/sysrq-trigger

I'll try to re-trigger that issue later today, and report back the findings.

Thanks,
Ciprian.