[Cbe-oss-dev] [PATCH 1/6] cell: add per BE structure with info about its SPUs

[Arnd Bergmann]

On Monday 12 February 2007 18:48, André Detsch wrote:
> Arnd Bergmann wrote:
> > Why do you even care about isolated spus in the first place?
> 
> We should ensure that there is at least one be that has enough 
> non-isolated spus to accommodate all contexts of the affinity group, to 
> avoid having a group that will never be completely scheduled.
> 
> The code uses the number of isolated spus in affinity_assert, but, since
> isolated contexts come and go, we actually don't have guarantees. This 
> is a design issue we have to care about. What would you suggest?
> 

I guess the logic is ok, but you should not use the term 'isolated' with
this meaning. An isolated context is using a specific hardware feature,
and that currently relies on marking the context as SPU_CREATE_NOSCHED.
You can create nonisolated contexts with that flag and need to treat
them in the same way, and in the future we might want to be able to
create isolated contexts that actually _can_ be scheduled, though that
is a hard problem.

	Arnd <><