On Sun, 11 Oct 2020 11:24:41 +0200 Heiner Kallweit wrote: > >> qeth_qdio_poll > >> netvsc_channel_cb > >> napi_watchdog > > > > This one runs from a hrtimer, which I believe will be a hard irq > > context on anything but RT. I could be wrong. > > > > A similar discussion can be found e.g. here: > https://lore.kernel.org/netdev/20191126222013.1904785-1-bige...@linutronix.de/ > However I don't see any actual outcome.
Interesting, hopefully Eric will chime in. I think the hrtimer issue was solved. But I'm not actually seeing a lockdep_assert_irqs_disabled() in __raise_softirq_irqoff() in net, so IDK what that's for? In any case if NAPI thinks it has irqs off while they're not, and interacts with other parts of the kernel we may be in for a game of whack-a-mole. Perhaps a way around touching force_irqthreads directly in net/ would be some form of a helper like "theaded_local_irq_save" or such that'd disable IRQs only if force_irqthreads == 1? Is that cheating? :)
