[RFC] sched: low latency feedback to userspace

[Maximilian KrÃger]

I am planning to extend the CFS as part of my master thesis. I want 
user-threads to allow to decide whether to enter a critical section or 
call sched_yield()
For tight synchronized workloads it might be useful, to only start 
certain short tasks, when they still can be completed in the current 
time slice without being interrupted by the scheduler.
Since low latency is key, my current plan is to use a shared-mapped page 
for signaling and only use a syscall for the setup. I'd be curious, if 
you might find this useful in general and if there is a chance for 
getting this accepted upstream, given my benchmarks can prove gives the 
intended benefits.

While these are very general questions, I have one detail question 
concerning how good the chances for getting this upstream are. Would you 
prefer, if I implemented the setup with an additional syscall, or as an 
extensions of existing syscalls (probably sched_setattr, sched_getattr).
greetings,
Maximilian KrÃger