Messages in this thread | | | Date | Tue, 7 Aug 2018 10:34:10 -0400 | From | Steven Rostedt <> | Subject | Re: [PATCH v12 3/3] tracing: Centralize preemptirq tracepoints and unify their usage |
| |
On Tue, 07 Aug 2018 10:10:59 -0400 Joel Fernandes <joelaf@google.com> wrote:
> On August 7, 2018 9:49:54 AM EDT, Steven Rostedt <rostedt@goodmis.org> wrote: > >On Tue, 7 Aug 2018 06:33:35 -0700 > >Joel Fernandes <joelaf@google.com> wrote: > > > >> Thanks, also one more thing I noticed in your patch, > >> lockdep_hardirqs_off needs to be called before all other probes but > >> you're calling it after. This is why I registered it with INT_MAX: > >> > >> register_trace_prio_irq_disable(lockdep_hardirqs_off, NULL, INT_MAX); > >> > >> Without it you may get annotation warnings. Thanks, > > > >Interesting. I was following the old way where we called the tracing > >code before calling the lockdep code (all hard coded and not from > >trace events). Is this have something to do with calling the code from > >a tracepoint? > > > >Do you have an example that could trigger the warning? > > > > I remember the warnings but can't remember now how I triggered them. > I think I saw them with the irqsoff tracer or irq trace events > running, with lockdep turned on.
I'll see if I can trigger it. I'll run this all through my tests.
> > Also an irq disable probe that does a lockdep assert that irqs are > disabled could trigger it? >
You mean if someone add a tracepoint callback to the irq disable tracepoint, and did a lockdep assert to make sure interrupts are disabled?
-- Steve
| |