On Sun, Aug 12, 2018 at 6:07 PM <leo....@linaro.org> wrote: > > On Sun, Aug 12, 2018 at 01:12:41PM +0200, Rafael J. Wysocki wrote: > > On Fri, Aug 10, 2018 at 11:03 AM <leo....@linaro.org> wrote:
[cut] > > > > Assuming shot noise wakeups, if > > drv->states[drv->state_count-1].target_residency is less than > > TICK_USEC, the tick will be stopped for CPUs more often on average > > with the patch applied (simply because the idle duration range for > > which it will not be stopped is narrower then). > > Yes, good point, so in the new approach I try to change the code > to compare with next tick delta rather than TICK_USEC, it can keeps > running tick for the tick with long expire time (similiar with > comparing with TICK_USEC) but we also can stop tick if the tick is likely > to break idle residency. We tried something similar and the results were not encouraging. Please see https://lore.kernel.org/lkml/079e16b6-2e04-2518-0553-66becab22...@tu-dresden.de/
