Hello. On Tue, Jun 15, 2021 at 01:09:59PM -0400, Steven Rostedt wrote: > On Tue, 15 Jun 2021 18:24:20 +0200 > Rasmus Villemoes <rasmus.villemoes@xxxxxxxxx> wrote: > > > > ~ # uname -r > > > 5.10.42-00001-g10216cf63a12 > > > ~ # grep -ow threadirqs /proc/cmdline > > > threadirqs > > > ~ # zcat /proc/config.gz | grep FORCED_THREADING > > > CONFIG_IRQ_FORCED_THREADING=y > > > ~ # dmesg | grep WARNING > > > ~ # > > > > And as an extra data point, it also doesn't trigger on 5.10.41-rt42 > > configured without PREEMPT_RT but with threadirqs on the command line. > > Sounds to me that there's a "spin_lock_irq*" somewhere in the path, because > from what I can see, there's not much difference with the IRQ code between > 5.10.41 and 5.10.41-rt42. But if you are seeing it only with PREEMPT_RT > set, that tells me that without PREEMPT_RT, interrupts are disabled at that > point, but not with PREEMPT_RT. The only thing I can think of that would do > that is a spin_lock_irq*() taken (not a raw_spin_lock_irq*()). This reminds me [1] and [2]. I'm carrying forward [3] in my domestic kernel build to cope with that. /cc'ing people involved back then. [1] https://lore.kernel.org/lkml/20201204201930.vtvitsq6xcftjj3o@spock.localdomain/ [2] https://bugzilla.kernel.org/show_bug.cgi?id=202453 [3] https://gitlab.com/post-factum/pf-kernel/-/commit/f7c99d74cca99d71179d63e827811f0df51bd8fc -- Oleksandr Natalenko (post-factum)
