Re: [Lse-tech] Bug in sys_sched_yield

Walt Drummond
2001-04-16T16:00:53Z

Hubertus Franke writes:
> I think that all data accesses particularly to __aligned_data
> should be performed through logical ids. There's a lot of remapping
> going on, due to the mix of logical and physical IDs.
>
> If indeed the physical numbers are sparse (like we had on a 4x4
> NUMA system) then indexing doesn't work anyway.

This is exactly right. On IA64, we have to hide the physical
processor ID (processor bus/local ID pair) completely. As far as I
can see, but it's been awhile, so forgive me if I miss one or two,
IA64 doesn't expose the physical processor ID at all, outside the IPI
and AP startup code.

> The right approach to me seems to move everything including p->processor
> to logical and the few locations where needed otherwise (?) should
> be moved to have the translation from performed there.

Yep. If not simply to make the generic kernel code clearer, this will
also make it easier to support non-linear (NUMA) systems.

--Walt