[PATCH 1/1] powerpc: Ignore IPIs to offline CPUs

[Brian King]

Since there is nothing to stop an IPI from occurring to an
offline CPU, rather than printing a warning to the logs,
just ignore the IPI. This was seen while stress testing
SMT enable/disable.

Signed-off-by: Brian King <brking at linux.vnet.ibm.com>
---

 arch/powerpc/platforms/pseries/xics.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff -puN arch/powerpc/platforms/pseries/xics.c~powerpc_xics_ipi_offline arch/powerpc/platforms/pseries/xics.c
--- linux-2.6/arch/powerpc/platforms/pseries/xics.c~powerpc_xics_ipi_offline	2010-04-20 20:46:06.000000000 -0500
+++ linux-2.6-bjking1/arch/powerpc/platforms/pseries/xics.c	2010-04-20 20:47:53.000000000 -0500
@@ -545,7 +545,8 @@ static irqreturn_t xics_ipi_dispatch(int
 {
 	unsigned long *tgt = &per_cpu(xics_ipi_message, cpu);
 
-	WARN_ON(cpu_is_offline(cpu));
+	if (cpu_is_offline(cpu))
+		return IRQ_HANDLED;
 
 	mb();	/* order mmio clearing qirr */
 	while (*tgt) {
_