Hi Masami, On Thu, Aug 2, 2018 at 7:55 AM, Masami Hiramatsu wrote: > Hi Joel, > > I found this caused several issues when testing ftrace. > > #1) ftrace boottest (FTRACE_STARTUP_TEST) fails This sadly appears to be a real issue. The startup test for "preemptirqsoff" tracer fails, however it passes for only preemptoff or only irqsoff. I tested only the last 2 tracers, not the first one, that's why I didn't catch it. I need to debug this more. > #2) mmiotrace reports "IRQs not enabled as expected" error > #3) lock subsystem event boottest causes "IRQs not disabled as expected" error (sometimes) Could you try the below patch and let me know if you still see the issue? In the v11 I removed the lockdep_recursing() check since it seemed unnecessary. But I'd like to rule out that there's still some issue lurking there. Thanks and I appreciate your help, diff is attached to this email. > #4) ftracetest test.d/event/toplevel-enable.tc causes "suspicious RCU usage" warning I sent a patch fixing this with you on CC. I tested that it fixes the issue you're reporting.