[PATCH] ARM64: smp: Silence suspicious RCU usage with ipi tracepoints

Stephen Boyd sboyd at codeaurora.org
Wed Jun 24 14:59:30 PDT 2015

On 06/24/2015 02:29 PM, Peter Zijlstra wrote:
> 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'.

Fair enough. I can resend or whoever applies this patch can
s/Silence/Fix/ on the $subject.

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