Re: [ANNOUNCE][RFC] PlugSched-6.4 for 2.6.18-rc2

[Peter Williams <pwil3058@bigpond.net.au>]

Al Boldi wrote:
> Peter Williams wrote:
>> Al Boldi wrote:
>>> Peter Williams wrote:
>>>> Al Boldi wrote:
[bits deleted]
>>>>> It may be really great, to allow schedulers perPid parent, thus
>>>>> allowing the stacking of different scheduler semantics.  This could
>>>>> aid flexibility a lot.
>>>> I'm don't understand what you mean here.  Could you elaborate?
>>> i.e:  Boot the kernel with spa_no_frills, then start X with spa_ws.
>> It's probably not a good idea to have different schedulers managing the
>> same resource.  The way to do different scheduling per process is to use
>> the scheduling policy mechanism i.e. SCHED_FIFO, SCHED_RR, etc.
>> (possibly extended) within each scheduler.  On the other hand, on an SMP
>> system, having a different scheduler on each run queue (or sub set of
>> queues) might be interesting :-).  
> 
> What's wrong with multiple run-queues on UP?

A really high likelihood of starvation of some tasks.

Peter
-- 
Peter Williams                                   pwil3058@bigpond.net.au

"Learning, n. The kind of ignorance distinguishing the studious."
  -- Ambrose Bierce