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

Ingo Molnar
2003-12-08T23:37:09Z

the thing that makes balancing-only driven SMT possible with current 2.6.0
is the overbalancing we do (to have cross-CPU fairness). Previous
iterations of the O(1) scheduler (all the 2.4 backports) didnt do this so
all the add-on SMT schedulers tended to have a problem achieving good SMT
distribution. Now that we more agressively balance, this isnt such a big
issue anymore.

so i tend to lean towards your SMT patch, it's much easier to maintain
than my runqueue-sharing approach. The performance is equivalent as far as
i can see (around 20%, and a stabilization of the distribution of
runtimes) - but please also boot my patch and repeat the exact same
measurements you did.

Ingo