Date: Wed, 24 Jun 2015 23:29:30 +0200
From: Peter Zijlstra <peterz@infradead.org>
To: Stephen Boyd <sboyd@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will.deacon@arm.com>, linux-kernel@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org,
        John Stultz <john.stultz@linaro.org>,
        Steven Rostedt <rostedt@goodmis.org>,
        "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
        Nicolas Pitre <nicolas.pitre@linaro.org>
Subject: Re: [PATCH] ARM64: smp: Silence suspicious RCU usage with ipi
 tracepoints
Message-ID: <20150624212930.GC12596@twins.programming.kicks-ass.net>
References: <1435176858-9568-1-git-send-email-sboyd@codeaurora.org>
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On Wed, Jun 24, 2015 at 01:14:18PM -0700, Stephen Boyd wrote:
> John Stultz reported an RCU splat on ARM with ipi trace events
> enabled. It looks like the same problem exists on ARM64.
> 
> At this point in the IPI handling path we haven't called
> irq_enter() yet, so RCU doesn't know that we're about to exit
> idle and properly warns that we're using RCU from an idle CPU.
> Use trace_ipi_entry_rcuidle() instead of trace_ipi_entry() so
> that RCU is informed about our exit from idle.

I have a problem with $subject. It says 'silence', whereas afaict this
fixes an actual bug, so it should be 'fixes'.
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