On Tue, Mar 24, 2015 at 04:10:37PM +0000, Peter Zijlstra wrote: > On Tue, Mar 24, 2015 at 10:44:24AM +0000, Morten Rasmussen wrote: > > > > Maybe remind us why this needs to be tied to sched_groups ? Why can't we > > > > attach the energy information to the domains? > > > In the current domain hierarchy you don't have domains with just one cpu > > in them. If you attach the per-cpu energy data to the MC level domain > > which spans the whole cluster, you break the current idea of attaching > > information to the cpumask (currently sched_group, but could be > > sched_domain as we discuss here) the information is associated with. You > > would have to either introduce a level of single cpu domains at the > > lowest level or move away from the idea of attaching data to the cpumask > > that is associated with it. > > > > Using sched_groups we do already have single cpu groups that we can > > attach per-cpu data to, but we are missing a top level group spanning > > the entire system for system wide energy data. So from that point of > > view groups and domains are equally bad. > > Oh urgh, good point that. Cursed if you do, cursed if you don't. Bugger.
Yeah :( I don't really care which one we choose. Adding another top level domain with one big group spanning all cpus, but with all SD flags disabled seems less intrusive than adding a level at the bottom. Better ideas are very welcome. -- 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/
