On Thu, Jul 18, 2013 at 05:45:46PM +0530, Srikar Dronamraju wrote: > We take locks if and only if we see imbalance and want to pull the > tasks. > However if the newly idle balance is not finding an imbalance then this > may not be an issue. > > Probably /proc/schedstats will give a better picture.
Right, so we're interested in move_tasks() calls that fail to 'deliver'. There's a few conditions in there that can cause us to not move a task, most of them not counted. The few that are; are from can_mirgrate_task(): se.statistics.nr_failed_migrations_affine se.statistics.nr_failed_migrations_running se.statistics.nr_failed_migrations_hot If we see significant increments on those we'll be taking locks. The only one I can see a good way around is the hot one, we could ignore hotness in favour of newidle -- although I could see that being detrimental, we'll just have to try or so ;-) _running shouldn't be much of a problem since we don't bother if nr_running <= 1. And _affine is out of our reach anyway. -- 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/
