[RFC PATCH] MIPS/octeon: select online CPU for irq

[Hillf Danton]

The tiny probability of dead loop is removed if all bound CPUs of given irq go
offline, and selected CPU is always checked to be online.

Signed-off-by: Hillf Danton <dhillf@xxxxxxxxx>
---
 arch/mips/cavium-octeon/octeon-irq.c |   32 +++++++++++---------------------
 1 files changed, 11 insertions(+), 21 deletions(-)

diff --git a/arch/mips/cavium-octeon/octeon-irq.c
b/arch/mips/cavium-octeon/octeon-irq.c
index ffd4ae6..7b678e3 100644
--- a/arch/mips/cavium-octeon/octeon-irq.c
+++ b/arch/mips/cavium-octeon/octeon-irq.c
@@ -198,28 +198,18 @@ static void __init octeon_irq_init_core(void)

 static int next_cpu_for_irq(struct irq_data *data)
 {
-
 #ifdef CONFIG_SMP
-	int cpu;
-	int weight = cpumask_weight(data->affinity);
-
-	if (weight > 1) {
-		cpu = smp_processor_id();
-		for (;;) {
-			cpu = cpumask_next(cpu, data->affinity);
-			if (cpu >= nr_cpu_ids) {
-				cpu = -1;
-				continue;
-			} else if (cpumask_test_cpu(cpu, cpu_online_mask)) {
-				break;
-			}
-		}
-	} else if (weight == 1) {
-		cpu = cpumask_first(data->affinity);
-	} else {
-		cpu = smp_processor_id();
-	}
-	return cpu;
+	int cpu = smp_processor_id();
+
+	cpu = cpumask_next_and(cpu, data->affinity, cpu_online_mask);
+	if (cpu < nr_cpu_ids)
+		return cpu;
+
+	cpu = cpumask_first_and(data->affinity, cpu_online_mask);
+	if (cpu < nr_cpu_ids)
+		return cpu;
+
+	return smp_processor_id();
 #else
 	return smp_processor_id();
 #endif
--
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