Re: [PATCH] sched,numa: document and fix numa_preferred_nid setting

Ingo Molnar
2015-06-18T16:13:13Z

* Srikar Dronamraju <srikar@linux.vnet.ibm.com> wrote:

> > if (p->numa_group) {
> > if (env.best_cpu == -1)
> > @@ -1513,7 +1520,7 @@ static int task_numa_migrate(struct task_struct *p)
> > nid = env.dst_nid;
> >
> > if (node_isset(nid, p->numa_group->active_nodes))
> > - sched_setnuma(p, env.dst_nid);
> > + sched_setnuma(p, nid);
> > }
> >
> > /* No better CPU than the current one was found. */
> >
>
> Overall this patch does seem to produce better results. However numa02
> gets affected -vely.

Huh?

numa02 is the more important benchmark of the two. 'numa01' is a conflicting
workload that is a lot more sensitive to balancing details - while 'numa02' is a
nicely partitioned workload that should converge as fast as possible.

So if numa02 got worse then it's a bad change.

Thanks,

Ingo