On 05/02/2014 03:37 AM, Mike Galbraith wrote: > On Fri, 2014-05-02 at 02:30 -0400, Rik van Riel wrote: >> On 05/02/2014 02:13 AM, Mike Galbraith wrote: >>> On Fri, 2014-05-02 at 00:42 -0400, Rik van Riel wrote: >>> >>>> Whether or not this is the right thing to do remains to be seen, >>>> but it does allow us to verify whether or not the wake_affine >>>> strategy of always doing affine wakeups and only disabling them >>>> in a specific circumstance is sound, or needs rethinking... >>> >>> Yes, it needs rethinking. >>> >>> I know why you want to try this, yes, select_idle_sibling() is very much >>> a two faced little bitch. >> >> My biggest problem with select_idle_sibling and wake_affine in >> general is that it will override NUMA placement, even when >> processes only wake each other up infrequently... > > Hm, seems the thing to do would be to tell select_task_rq_fair() to keep > it's mitts off of tasks that the numasched stuff has placed rather than > decapitating select_idle_sibling() or some other drastic measure.
Thing is, if tasks are waking each other up frequently enough, we probably DO want to place them near each other with select_idle_sibling. We just cannot afford to have it as the default behaviour for casual wakeup activity, because it will mess up other things. -- All rights reversed -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
