Re: RT scheduler config, suggestions and questions

[Max Krasnyanskiy <maxk@qualcomm.com>]

Peter Zijlstra wrote:
> On Wed, 2008-02-06 at 07:36 +0100, Peter Zijlstra wrote:
> 
>>> btw I can see "watchdog" being very useful to catch hard-RT tasks that exceed the deadline.
>>> But's it gotta be per thread.
>> It is.
>>
>>> Single setting per user is not enough. Unless a use has a single RT task.
>> ?
> 
> Ah, its starting to make sense, you want it configurable per thread, not
> process wide. Yes, I see how that is useful, just no idea how to expose
> that to user-space atm.
Yes. That's what I meant. I don't think overall per process setting is that useful.
Per thread though would be useful.

How to expose that to the user-space ? The best option in my opinion is to extend
struct sched_param. That way both sched_setparam() and pthread_attr_setschedparam() 
can be used to set new attributes and it's backwards compatible.
Something like:

struct sched_param {
	...
	unsigned int sched_rt_limit;
	unsigned int sched_rt_...;
};

Max