> On 27 May 2016, at 3:21 , Ihor Kuz UNSW <[email protected]> wrote:
>
> The basic model is that every CAmkES thread (unless specified otherwise) has 
> a scheduling context (SC).  The above attributes set the parameters of the 
> associated scheduling context.  If not explicitly specified then a thread’s 
> SC has default values (10000) for the period and budget.  The values are in 
> microseconds.
>
> With regards to the period and budget they match the same attributes in the 
> scheduling contexts as provided by the kernel.  See the kernel manual (RT 
> version) for more details.  Priority is the same as in previous versions of 
> seL4.

note that if budget=period, you get the old seL4 scheduling behaviour (where 
period replaces the time slice).

>> Any information about them? How they are supposed to be isolated from each 
>> other then?

If you want to know how this can provide temporal isolation, then the answer is 
that you can use the budget to prevent a high-prio thread from monopolising the 
CPU. A thread with period T and budget C is guaranteed to consume no more than 
C/P of the available CPU bandwidth, irrespective of prio. If that’s the 
highest-prio thread, then (P-C)/P bandwidth is left to other threads.

There’ll be a white paper out shortly.

Gernot

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