On Mon, May 18, 2015 at 07:59:40PM +0530, Srikar Dronamraju wrote: > > We should never get preferred_nid set when nr_cpus_allowed == 1, see the > > hunk that changes task_tick_numa. > > > > So we set preferred = -1 on pinning, do not partake in numa balancing > > while this is so, therefore it should still be so when we dequeue, > > right? > > lets say if a thread were to do a sched_setaffinity on itself ; > would it not call account_numa_dequeue before account_numa_enqueue?
Yes, but it would call dequeue while nr_cpus_allowed was still the 'old' value. And it will call enqueue when its the 'new' value. > Also setting preferred = -1 in set_cpus_allowed avoids us from setting > it at account_numa_enqueue. account_numa_enqueue() would probably be > called more times than set_cpus_allowed. This is true; and that makes sense. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
