On 21 June 2013 16:38, Arjan van de Ven <ar...@linux.intel.com> wrote: > On 6/21/2013 1:50 AM, Morten Rasmussen wrote: >> A hint when a task is moved to a new cpu is too late if the migration >> shouldn't have happened at all. If the scheduler knows that the cpu is >> able to switch to a higher p-state it can decide to wait for the p-state >> change instead of migrating the task and waking up another cpu. > > oops sorry I misread your mail (lack of early coffee I suppose) > > I can see your point of having a thing for "did we ask for all the performance > we could ask for" prior to doing a load balance (although, for power > efficiency, > if you have two tasks that could run in parallel, it's usually better to > run them in parallel... so likely we should balance anyway)
Not necessarily, especially if parallel running implies powering up a full cluster just for one CPU (it depends on the hardware but for example a cluster may not be able to go in deeper sleep states unless all the CPUs in that cluster are idle). -- Catalin -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
