On Fri, Jun 12, 2015 at 09:32:45AM +0200, Peter Zijlstra wrote: > On Thu, Jun 11, 2015 at 07:36:05PM +0200, Frederic Weisbecker wrote: > > Restart the tick when necessary from the irq exit path. It makes nohz > > full more flexible and allow it to piggyback the tick restart on the > > scheduler IPI in the future instead of sending a dedicated IPI that > > often doubles the scheduler IPI on task wakeup. This will require > > careful review of resched_curr() callers. > > This seems to assume schedule_ipi() callers use irq_exit(), this is > false.
Indeed there will be that too. Note the current patch doesn't yet rely on schedule_ipi(), we are still using the nohz ipis. But introducing the tick restart on irq exit prepares for later piggybacking on scheduler_ipi(). I think this will involve changes on got_nohz_idle_kick(), renamed to got_nohz_kick() and include nohz full related checks to trigger the irq_enter()/exit() pair. -- 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/
