Re: [PATCH v2 04/13] sched: Introduce SD_ASYM_CPUCAPACITY sched_domain topology flag

From: Morten Rasmussen
Date: Mon Jul 11 2016 - 06:40:49 EST


On Mon, Jul 11, 2016 at 11:55:23AM +0200, Peter Zijlstra wrote:
> On Wed, Jun 22, 2016 at 06:03:15PM +0100, Morten Rasmussen wrote:
> > Add a topology flag to the sched_domain hierarchy indicating
> > sched_groups at this sched_domain level having different per cpu
> > capacity (e.g. big.LITTLE big-only and little-only groups) or groups in
> > sibling domains with different capacity.
>
> > IOW, domains not spanning cpus
> > of all available capacities up until and including the first level
> > spanning cpus of all capacities available system wide.
>
> This ^, which would be SD1 below, why? I would expect only SD2 to be
> tagged, since that does indeed have asymmetric capacities.

That would make most sense, but it complicates how we can use the flag.
See reply to your related question for patch #5.