On Mon, Jun 26, 2017 at 11:20:54AM -0400, Rik van Riel wrote: > Oh, indeed. I guess in wake_affine() we should test > whether the CPUs are in the same NUMA node, rather than > doing cpus_share_cache() ?
Well, since select_idle_sibling() is on LLC; the early test on cpus_share_cache(prev,this) seems to actually make sense. But then cutting out all the other bits seems wrong. Not in the least because !NUMA_BALACING should also still keep working. > Or, alternatively, have an update_numa_stats() variant > for numa_wake_affine() that works on the LLC level? I think we want to retain the existing behaviour for everything larger than LLC, and when NUMA_BALANCING, smaller than NUMA. Also note that your use of task_h_load() in the new numa thing suffers from exactly the problem effective_load() is trying to solve.
