On Sun, Jul 16, 2017 at 11:08:07PM -0700, Tony Lindgren wrote: > * Alex Shi <alex.shi@xxxxxxxxxx> [170716 16:25]: > > I reused the rcu_irq_enter_irqson() from RCU_NONIDLE to avoid this issue. > > It works fine. > > > > Tony, Could you like to give a tested-by if this patch works for you. > > Yeah that keeps things booting for me with no splats so: > > Tested-by: Tony Lindgren <tony@xxxxxxxxxxx> > > In general, it seems we're missing the knowledge in Linux kernel > of when the entire system is idle. Right now it seems that only > cpuidle_coupled knows that? > > We could probably simplify things by adding some PM state for > entire system idle. Then cpuidle code and timer code could use > that to test when it's safe to do whatever the SoC needs to do > to enter deeper power states. > > If we already have something like that, please do let me know :) Well, we used to have CONFIG_NO_HZ_FULL_SYSIDLE, which detected full-system idle lazily so as to avoid scalability bottlenecks. https://lwn.net/Articles/558284/ No one was using it, so I removed it last merge window. The patch that removed it is at sysidle.2017.05.11a, which can probably still be reverted cleanly. Or just use v4.11 or earlier. Thanx, Paul -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
