On Mon, Nov 10, 2014 at 06:19:02PM +0100, Daniel Lezcano wrote: > >I really don't get why the governors should know about this though, its > >just another state, they should iterate all states and pick the best, > >given the power usage this state should really never be eligible unless > >we're QoS forced or whatnot. > > The governors just don't use the poll state at all, except for a couple of > cases in menu.c defined above in the previous email. What is the rational of > adding a state in the cpuidle driver and do everything we can to avoid using > it ? From my POV, the poll state is a special state, we should remove from > the driver's idle states like the arch_cpu_idle() is a specific idle state > only used in idle.c (but which may overlap with an idle state in different > archs eg. cpu_do_idle() and the 0th idle state).
So I disagree, I think poll-idle is an idle mode just like all the others. It should be an available state to the governor and it should treat it like any other. I don't tihnk the whole ARCH_HAS_CPU_RELAX thing makes any kind of sense, _every_ arch has some definition of it, the generic polling loop is always a valid idle implementation. What we can do is always populate the idle state table with it before calling the regular drivers. If the arch drivers have a 'better' latency_req==0 idle routine -- note my argument on the ppc issue, I think its wrong -- it can replace the existing one. We should further remove all the special casing in the governors, its always a valid state, but it should hardly ever be the most desirable state. I think the whole arch specific idle loop is a mistake, we already have an (arch) interface into the idle routines, we don't need yet another. -- 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/
