[okl4-developer] L4 > scheduler

[Antonin SUBTIL]

Hello,

About scheduling, some questions. I know some can be weird, I'm sorry for
that, I'm just trying to understand exactly how it works, and how
deterministic it can be.

- Is a domain like a personnality? (like an OS, an RT task ... or like a
time partition) <- I'm trying to understand isolation between threads in
scheduling. I know it's a set of hardware threads and processing units.
- What happen if we have two threads with the same priority? Fifo? lifo?
-about threads, priority and domain : if domaine is like a time partition,
can a thread only execute in its domain, whatever its priority is? (then can
we see a two stage scheduling : domains and then thread inside domains)
- If domain are like "VM"/time partition... is there a background domain
(like dom0 in Xen), preemptive (...) ?
- what about thread needing lesser-priority threads ? If A is an high prio
thread and need a message to/from B, a low prio thread, with all the IPC
stuff, will A be stopped and resumed after B is done (maybe after
C,D,E,F...) , or will A give temporarly a high prio for B to execute and
resume? (B is not created by A, otherwise the problem is solved)

- About real-time : is it event-driven or time-driven? Looks to me like
priority-driven, so maybe more time than event but I'm not sure (page 29 of
okl4 prog manual).
- Is it possible for some "malware" to change the priority of threads and
then not realase proc units? Time quanta seems to avoid unrealasing, yeti'm
not sure in a case of malware.



Thanks

-- 
Antonin Subtil,
35 rue Donissan
FR-33000 Bordeaux
+33 (0)6.77.40.17.69
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