On Wed, Aug 16, 2017 at 09:32:44AM -0400, Steven Rostedt wrote:
> On Wed, 16 Aug 2017 11:17:36 +0900
> Byungchul Park <[email protected]> wrote:
>
>
> > Yes, that's what I intended. IOW:
> >
> > If (we found a proper sd, not having SD_PREFER_SIBLING?)
> > use the sd;
> > else if (we found a proper sd, having SD_PREFER_SIBLING?)
> > use the smallest sd among SD_PREFER_SIBLING sds;
>
> BTW, what do you mean by "smallest sd"?
There might be more than one SD_PREFER_SIBLING domain in its hierachy.
In that case, we have to choose one of them. Imagine the following
example, in case that the source cpu is cpu 0:
[Domain hierachy for cpu 0]
cpu 0 -+ domain 1 -+
| SD_PREFER_SIBLING flaged |
cpu 1 -+ +- domain 2
| SD_PREFER_SIBLING flaged
cpu 2 -+---------------------------+
|
cpu 3 -+
In this case, we have to choose domain 1 than 2, because cpus in domain 1
are closer to the source cpu, cpu 0. That's what I meant.
