Re: [PATCH V6 1/7] Sched: Scheduler time slice extension

[Thomas Gleixner <tglx@linutronix.de>]

On Thu, Jul 03 2025 at 05:38, Prakash Sangappa wrote:
>> On Jul 1, 2025, at 5:36 AM, Thomas Gleixner <tglx@linutronix.de> wrote:
>>
>> Also if we go there and allow non-RT tasks to delay scheduling, then we
>> need a control mechanism to enable/disable this mechanism on a per task
>> or process basis. That way a RT system designer can prevent random
>> user space tasks, which think they are the most important piece, from
>> interfering with truly relevant RT tasks w/o going to chase down source
>> code and hack it into submission.
>
> Could the per task  control mechanism be thru /proc?

Is that a serious question?

> Wonder how easy it will be to administer such control.

Obviously it's horrible.

That's what prctl() is for. Plus a proper inheritance mechanism on
fork/exec along with a system wide default which can be controlled via
the kernel command line.

> Alternatively, can we have a config option to apply to LAZY only?
> This will not provide the finer  control as you suggested. 

A config option is not solving anything; it's just a lazy hack to avoid
the hard work of a proper and future proof ABI design.

Thanks,

        tglx