4.1-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Stephen Boyd <[email protected]>

commit be081d9bf3e163a9ed1ca2f0f14f08424c7f9016 upstream.

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.

Cc: John Stultz <[email protected]>
Cc: Nicolas Pitre <[email protected]>
Acked-by: Steven Rostedt <[email protected]>
Reviewed-by: Paul E. McKenney <[email protected]>
Fixes: 45ed695ac10a ("ARM64: add IPI tracepoints")
Signed-off-by: Stephen Boyd <[email protected]>
Signed-off-by: Catalin Marinas <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

---
 arch/arm64/kernel/smp.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -569,7 +569,7 @@ void handle_IPI(int ipinr, struct pt_reg
        struct pt_regs *old_regs = set_irq_regs(regs);
 
        if ((unsigned)ipinr < NR_IPI) {
-               trace_ipi_entry(ipi_types[ipinr]);
+               trace_ipi_entry_rcuidle(ipi_types[ipinr]);
                __inc_irq_stat(cpu, ipi_irqs[ipinr]);
        }
 
@@ -612,7 +612,7 @@ void handle_IPI(int ipinr, struct pt_reg
        }
 
        if ((unsigned)ipinr < NR_IPI)
-               trace_ipi_exit(ipi_types[ipinr]);
+               trace_ipi_exit_rcuidle(ipi_types[ipinr]);
        set_irq_regs(old_regs);
 }
 


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to