On Fri, 02 Jun 2017 19:54:32 +1000
Michael Ellerman <m...@ellerman.id.au> wrote:
> >> @@ -672,10 +672,19 @@ static void __init pcpu_fc_free(void *ptr, size_t
> >> size)
> >>
> >> static int pcpu_cpu_distance(unsigned int from, unsigned int to)
> >> {
> >> - if (cpu_to_node(from) == cpu_to_node(to))
> >> - return LOCAL_DISTANCE;
> >> - else
> >> - return REMOTE_DISTANCE;
> >> +#ifndef CONFIG_NUMA
> >> + return LOCAL_DISTANCE;
> >> +#else
> >> + int from_nid, to_nid;
> >> +
> >> + from_nid = early_cpu_to_node(from);
> >> + to_nid = early_cpu_to_node(to);
> >> +
> >> + if (from_nid == -1 || to_nid == -1)
> >> + return LOCAL_DISTANCE; /* Or assume remote? */
> >> +
> >> + return node_distance(from_nid, to_nid);
> >
> > If you made node_distance() return LOCAL_NODE for !NUMA, this
> > should fall out and not require the ifdef?
>
> Maybe yeah. This is designed to be minimal for backporting though.
Okay fair enough. Is it expected to get back -1 from this ever? I think
all we need is local vs not local to direct whether to pack CPUs into
the same chunks or not so I wonder if the equality test is simpler.
Probably not a big deal though. Patch looks good as is.
Thanks,
Nick
