Re: re. Spurious wakeup on a newly created kthread

From: Michal Hocko
Date: Mon Jun 27 2022 - 06:18:53 EST


On Mon 27-06-22 17:21:12, Tejun Heo wrote:
> Hello, Michal.
>
> On Mon, Jun 27, 2022 at 10:07:22AM +0200, Michal Hocko wrote:
> > So if somebody has woken up our thread from inside kthread() then it
> > doesn't have that pointer on the stack and I couldn't it find elsewhere
> > either. Maybe somebody has an idea where to look at.
>
> One way could be bpftrace'ing or printking __wake_up_common() and
> friends to dump backtrace if it's trying to wake a kthread whose comm
> starts with kworker/ and doesn't have (struct worker
> *)kthread_data(task)->pool set.

I am afraid I won't have a chance for a runtime debugging. All I have at
this stage is a crash dump.
--
Michal Hocko
SUSE Labs