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Date:   Tue, 07 Aug 2018 10:10:59 -0400
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Subject: Re: [PATCH v12 3/3] tracing: Centralize preemptirq tracepoints and unify their usage
To:     Steven Rostedt <rostedt@goodmis.org>
CC:     Joel Fernandes <joel@joelfernandes.org>,
        LKML <linux-kernel@vger.kernel.org>,
        "Cc: Android Kernel" <kernel-team@android.com>,
        Boqun Feng <boqun.feng@gmail.com>,
        Byungchul Park <byungchul.park@lge.com>,
        Ingo Molnar <mingo@redhat.com>,
        Masami Hiramatsu <mhiramat@kernel.org>,
        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
        Namhyung Kim <namhyung@kernel.org>,
        Paul McKenney <paulmck@linux.vnet.ibm.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Thomas Glexiner <tglx@linutronix.de>,
        Tom Zanussi <tom.zanussi@linux.intel.com>
From:   Joel Fernandes <joelaf@google.com>
Message-ID: <446AE5F2-39E0-46B6-8E0B-207E003DBF20@google.com>
Sender: linux-kernel-owner@vger.kernel.org
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On August 7, 2018 9:49:54 AM EDT, Steven Rostedt <rostedt@goodmis=2Eorg> w=
rote:
>On Tue, 7 Aug 2018 06:33:35 -0700
>Joel Fernandes <joelaf@google=2Ecom> 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=2E This is why I registered it with INT_MAX:
>>=20
>> register_trace_prio_irq_disable(lockdep_hardirqs_off, NULL, INT_MAX);
>>=20
>> Without it you may get annotation warnings=2E Thanks,
>
>Interesting=2E 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)=2E 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=2E I t=
hink I saw them with the irqsoff tracer or irq trace events running, with l=
ockdep turned on=2E

Also an irq disable probe that does a lockdep assert that irqs are disable=
d could trigger it?

thanks,

- Joel


>-- Steve

--=20
Sent from my Android device with K-9 Mail=2E Please excuse my brevity=2E