On Tue, Jun 3, 2014 at 11:28 AM, Peter Zijlstra <pet...@infradead.org> wrote: > On Tue, Jun 03, 2014 at 07:00:18PM +0200, Peter Zijlstra wrote: >> On Tue, Jun 03, 2014 at 09:52:22AM -0700, Andy Lutomirski wrote: >> > > So you could cheat and set it in pick_next_task_idle() and clear in >> > > put_prev_task_idle(), that way the entire idle loop, when running has it >> > > set. >> > > >> > >> > Isn't that a little late for sched_ttwu_pending? I guess it could be >> > okay, but I'm hesitant to muck around with the scheduler innards that >> > much. I don't see anything that'll break, though. >> >> Yeah, only later did I see you clear much earlier, which makes sense. > > Could we clear it from set_nr_and_not_polling()/set_nr_if_polling()? > That's the only two functions that'll kick a cpu out of its polling > loop, and we're already writing to the word anyhow.
I'd be nervous about this. I think it could break if cpuidle_idle_call decides not to idle for any reason, and there is plenty of complicated code in there. I'm currently working on some patches that might make this clearer. Give me a bit. --Andy -- Andy Lutomirski AMA Capital Management, LLC -- 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/
