Re: [PATCH v10 0/2] kernel/fork: beware of __put_task_struct calling context

[Peter Zijlstra]

On Wed, Jun 14, 2023 at 09:23:20AM -0300, Wander Lairson Costa wrote:
> Under PREEMPT_RT, __put_task_struct() indirectly acquires sleeping
> locks. Therefore, it can't be called from an non-preemptible context.
> 
> Instead of calling __put_task_struct() directly, we defer it using
> call_rcu(). A more natural approach would use a workqueue, but since
> in PREEMPT_RT, we can't allocate dynamic memory from atomic context,
> the code would become more complex because we would need to put the
> work_struct instance in the task_struct and initialize it when we
> allocate a new task_struct.

> 
> Wander Lairson Costa (2):
>   kernel/fork: beware of __put_task_struct calling context
>   sched: avoid false lockdep splat in put_task_struct()

Thanks!