On Wed, Nov 05, 2014 at 06:59:35PM +0800, Wanpeng Li wrote: > Hi Peter, > On 14/11/5 下午6:50, Peter Zijlstra wrote: > >On Wed, Nov 05, 2014 at 04:51:57PM +0800, Wanpeng Li wrote: > >>Note: dl task can be migrated successfully if rq is offline currently, > >>however, > >>I'm still not sure why task_rq(task)->rd->span just include the cpu which > >>the dl > >>task previous running on, so cpu_active_mask is used in the patch. > >> > >>Peterz, Juri? > >So the root domain span is for exclusive cpusets > >(Documentation/cgroups/cpusets.txt) where we fully separate sets of CPUs > >and have no load-balancing between the sets. > > > >For 'normal' setups the rd->span is the entire machine, but using > >cpusets you can create more (smaller) domains. > > I don't setup any cpusets related stuff, however, task_rq(task)->rd->span > just include the cpu which the dl task previous running on instead of the > entire machine in find_later_rq().
Ah, it could be that for offline cpus we have a singleton rd. Lemme try and remember wth we did there. -- 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/
