[PATCH] 2.5.21 deadlocks on UP (SMP kernel) w/ IOAPIC

diff --git a/arch/i386/kernel/io_apic.c b/arch/i386/kernel/io_apic.c
index bc41f615ccdd338a5d8ccf3fa0bd13b7df88b7c9..47bf74f3d6d03c85f06b74d7bc96835e16132dbe 100644 (file)
--- a/arch/i386/kernel/io_apic.c
+++ b/arch/i386/kernel/io_apic.c
@@ -251,7 +251,7 @@ static inline void balance_irq(int irq)
        irq_balance_t *entry = irq_balance + irq;
        unsigned long now = jiffies;
 
-       if (unlikely(entry->timestamp != now)) {
+       if ((entry->timestamp != now) && (smp_num_cpus > 1)) {
                unsigned long allowed_mask;
                int random_number;