From mboxrd@z Thu Jan  1 00:00:00 1970
From: peterz@infradead.org (Peter Zijlstra)
Date: Wed, 24 Jun 2015 23:29:30 +0200
Subject: [PATCH] ARM64: smp: Silence suspicious RCU usage with ipi
 tracepoints
In-Reply-To: <1435176858-9568-1-git-send-email-sboyd@codeaurora.org>
References: <1435176858-9568-1-git-send-email-sboyd@codeaurora.org>
Message-ID: <20150624212930.GC12596@twins.programming.kicks-ass.net>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

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'.