From: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
To: Philipp Schrader <philipp@peloton-tech.com>
Cc: linux-kernel@vger.kernel.org, mingo@kernel.org,
tglx@linutronix.de, paulmck@linux.vnet.ibm.com,
rostedt@goodmis.org
Subject: Re: [PATCH v3] tracing: Fix rcu splat from idle CPU on boot.
Date: Tue, 22 Dec 2015 15:46:49 +0100 [thread overview]
Message-ID: <20151222144645.GA29103@breakpoint.cc> (raw)
In-Reply-To: <20151214190709.GA19861@philipp-x250.peloton-tech.com>
On 2015-12-14 11:07:09 [-0800], Philipp Schrader wrote:
> With PREEMPT_RT and most of the lockdep-related options enabled I
> encountered this splat when booting our DRA7 evaluation module:
>
> [ 0.055073]
> [ 0.055076] ===============================
> [ 0.055079] [ INFO: suspicious RCU usage. ]
> [ 0.055084] 4.1.6+ #2 Not tainted
> [ 0.055086] -------------------------------
> [ 0.055090] include/trace/events/hist.h:31 suspicious
> rcu_dereference_check() usage!
…
> As per Steve Rotstedt's suggestion I changed the trace_* calls to
> trace_*_rcuidle calls. He pointed out that the trace points were getting
> triggered when rcu wasn't watching.
>
> Signed-off-by: Philipp Schrader <philipp@peloton-tech.com>
> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
I'm taking this for -RT. Is my assumption correct, that this goes into
the v4.5 merge window once everybody is back from holidays?
Sebastian
prev parent reply other threads:[~2015-12-22 14:46 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-03 21:29 [PATCH] tracing: Fix rcu splat from idle CPU on boot Philipp Schrader
2015-09-04 20:09 ` [PATCH v2] " Philipp Schrader
2015-12-14 19:07 ` [PATCH v3] " Philipp Schrader
2015-12-14 19:12 ` Philipp Schrader
2015-12-22 14:46 ` Sebastian Andrzej Siewior [this message]
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