On Mon, Mar 05, 2018 at 01:07:07PM +0100, Rafael J. Wysocki wrote: > On Mon, Mar 5, 2018 at 12:50 PM, Rafael J. Wysocki <[email protected]> wrote: > > On Mon, Mar 5, 2018 at 12:45 PM, Peter Zijlstra <[email protected]> > > wrote:
> >> So I think this is entirely wrong, I would much rather see something > >> like: > >> > >> tick_nohz_idle_go_idle(next_state->nohz); > >> > >> Where the selected state itself has the nohz property or not. > > > > Can you elaborate here, I'm not following? > > > >> We can always insert an extra state at whatever the right boundary point > >> is for nohz if it doesn't line up with an existing point. > > OK, I guess I know what you mean: to add a state flag meaning "stop > the tick if this state is selected". Yes, that. > That could work, but I see problems, like having to go through all of > the already defined states and deciding what to do with them. Shouldn't be too hard, upon registering a cpuidle driver to the cpuidle core, the core could go through the provided states and flag all those < TICK_USEC as not stopping, all those > TICK_USEC as stopping and splitting the state we'd select for TICK_NSEC sleeps, stopping it for < and disabling it for >.
