Re: [PATCH v2 1/4] sched/task: Add the put_task_struct_atomic_safe function

luca abeni
2023-02-17T19:04:53Z

Hi all,

On Fri, 17 Feb 2023 14:35:22 -0300
Daniel Bristot de Oliveira <bristot@redhat.com> wrote:

> On 1/30/23 08:49, Wander Lairson Costa wrote:
> >> Another thing, if you look at release_task_stack(), it either
> >> caches the outgoing stack for later use, or frees it via RCU
> >> (regardless of PREEMPT_RT). Perhaps we could follow that and just
> >> always punt the freeing of the task struct to RCU?
> >>
> > That's a point. Do you mean doing that even for !PREEMPT_RT?
> >
>
> It seems that Luca Abeni (in Cc) is hitting the bug in the non-rt
> kernel with SCHED_DEADLINE...
>
> adding him to the thread.

Thanks Daniel for adding me.

I triggered this "BUG: Invalid wait context" with a 5.15.76 kernel,
without PREEMPT_RT. I can reproduce it easily on a KVM-based VM; if
more information or tests are needed, let me know.

Luca