Re: [PATCH][RFC] make cpu_sibling_map a cpumask_t

[Rusty Russell <rusty@rustcorp.com.au>]

In message <3FD3FD52.7020001@cyberone.com.au> you write:
> I'm not aware of any reason why the kernel should not become generally
> SMT aware. It is sufficiently different to SMP that it is worth
> specialising it, although I am only aware of P4 and POWER5 implementations.

To do it properly, it should be done within the NUMA framework.  That
would allow generic slab cache optimizations, etc.  We'd really need a
multi-level NUMA framework for this though.

But patch looks fine.

> I have an alternative to Ingo's HT scheduler which basically does
> the same thing. It is showing a 20% elapsed time improvement with a
> make -j3 on a 2xP4 Xeon (4 logical CPUs).

Me too.

My main argument with Ingo's patch (last I looked) was technical: the
code becomes clearer if the structures are explicitly split into the
"per-runqueue stuff" and the "per-cpu stuff" (containing a my_runqueue
pointer).

I'd be very interested in your patch though, Nick.

Rusty.
--
  Anyone who quotes me in their sig is an idiot. -- Rusty Russell.