Re: [PATCH v4 1/1] Documentation: real-time: Add kernel configuration guide

[John Ogness]

On 2026-07-21, Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> wrote:
>> +``CONFIG_DEBUG_FS``
>> +^^^^^^^^^^^^^^^^^^^
>> +
>> +This is safe to include in real-time kernels, *provided that debugfs is
>> +not accessed during production runtime*.
>
> It is safe to have as long as you don't use it.
>
> I would drop it. That filesystem is not dangerous on its own. It depends
> on the options you change and how this affect the system.
> We used to have it always enabled because you needed it for tracing.
> This is no longer the case as it has its own tracefs which has its own
> live outside of debugfs. So I don't think it is needed to mention it.

Unfortunately, debugfs is needed to configure the fair deadline server:

    /sys/kernel/debug/sched/fair_server/cpu*/runtime

John Ogness