[Cbe-oss-dev] CONFIG_SCHED_SMT

[Benjamin Herrenschmidt]

On Tue, 2007-08-14 at 23:01 +0900, Hiroyuki Machida wrote:
> Hi Ben,
> 
> Thank you for explanation. I think cpu_sibling_map[] will be initialized
> according to cpu_spec. It's not platform specific, but common for PPC64.
> In case of Cell, SMT flag is set and sibling map is expected to set correctly
> in all Cell platform.  So it's better PS3 deconfig follows Cell defconfig.

That code:

	for_each_possible_cpu(cpu) {
		cpu_set(cpu, cpu_sibling_map[cpu]);
		if (cpu_has_feature(CPU_FTR_SMT))
			cpu_set(cpu ^ 0x1, cpu_sibling_map[cpu]);
	}

Is a hack and will be going a way when some of the work I'm currently
doing gets merged. The new code will rely on the

ibm,ppc-interrupt-server#s

property in the CPU mode. You need to make sure you get one of these
that represents your two threads.

Cheers,
Ben.