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

Steven Rostedt rostedt at goodmis.org
Wed Jun 24 18:01:31 PDT 2015

On Wed, 24 Jun 2015 23:29:30 +0200
Peter Zijlstra <peterz at infradead.org> 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'.

Agreed, otherwise Acked-by: Steven Rostedt <rostedt at goodmis.org>

-- Steve

More information about the linux-arm-kernel mailing list