[LITMUS^RT] Modifying Page Table Entry in gsnedf_schedule()

[Björn Brandenburg]

On 19.09.2014, at 17:56, Namhoon Kim <namhoonk at cs.unc.edu> wrote:

>> > Are interrupts disabled when we enter gsnedf_schedule()? Does anyone know how to modify page access bits in schedule() properly?
>> 
>> Yes, of course. Interrupts are always disabled while scheduling in Linux to defend against scheduler invocations within interrupts. You can easily see this for yourself by observing that gsnedf_schedule() is called from within schedule(), which disables all interrupts.
> 
> I can put the set_pte() and flush_tlb_page() in Linux schedule() after interrupts enabled, but I think it is not the proper way. I don't want to touch any Linux functions. What is the proper way to use smp_call_functions in LITMUS schedule()? 

There is no way to call such functions from within a plugin's schedule() callback. I'm afraid you'll have to design Dealing with interrupt and locking restrictions is one of the main issues that make scheduler development "fun"...

- Björn 
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