[PATCH] MAXCPU alterable in kernel config - needs testers

[Ivan Voras]

Kip Macy wrote:
>> Any word on how will they handle migration of threads across sockets (or
>> will it be OS's job)? Judging from T1 architecture, I think such event
>> would create a very large performance penalty, but I'm not an expert.
> 
> It is the job of the OS to take locality into account in thread
> scheduling. Moving between chips You'll just lose the L2 cache locality
> just as you would on a normal SMP.

I'm reading about the architecture now; it seems 8 threads of a core are 
divided into two thread groups (each of which has its own ALU) and 
there's a hierarchy of "closeness" in terms of moving threads between 
execution units:

1. inside of thread group (instantaneous)
2. between thread groups
3. between cores
4. between CPUs/sockets