The implementation of CPU reservation server

Udo A. Steinberg udo at hypervisor.org
Mon Jun 1 14:46:40 CEST 2009


On Mon, 1 Jun 2009 20:03:49 +0800 Sean (S) wrote:

S> I already go through your diploma thesis. This thesis describes the design
S> issues and implementation detail of the Periodic Mode support for Fiasco.
S> If I don't want to control thread execution with periods, deadlines and
S> etc. , how can I implement the functionality I mentioned?
S> 
S> My goal is that
S> 
S> In the system, there are several user threads. During a time interval,
S> some particular user threads will not be scheduled even though these
S> threads are in ready state.

In Fiasco all threads in the ready state are eligible for execution. In
fact, the ready state means that the thread is only waiting to be dispatched
by the scheduler. So if you don't want a thread to be scheduled, it must not
be in the ready state.

S> How can I implement it? Does any exist function/API support it?

Before we can give you a definite answer, we need to know why you don't
want a particular thread to be scheduled. Here are some questions:

1) What is the event that makes an otherwise ready thread ineligible to
execute (according to your use case)?

2) What is the event that makes it eligible for scheduling again?

Without answers to these questions we cannot tell you what API you might be
able to use or how you would have to implement such a mechanism yourself.

Cheers,

	- Udo
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