Re: [PATCH v12 0/3] tracing: Centralize preemptirq tracepoints and unify their usage

[Masami Hiramatsu]

Hi Joel,

Thank you for trying to fix that.

On Thu, 2 Aug 2018 19:57:09 -0700
Joel Fernandes <joelaf@xxxxxxxxxx> wrote:

> Hi Masami,
> 
> On Thu, Aug 2, 2018 at 7:55 AM, Masami Hiramatsu <mhiramat@xxxxxxxxxx> 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.

I tried the attached patch. But unfortunately I still see #1 and #2.
(#3 does not always occurred, I'll continue to test)

> > #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.

OK, I'll check it.

Thanks!

-- 
Masami Hiramatsu <mhiramat@xxxxxxxxxx>