Extend clear_irq_vector From: Yinghai Lu Clear the irq releated entries in irq_vector, irq_domain and vector_irq instead of clearing irq_vector only. So when new irq is created, it could reuse that vector. (actually is the second loop scanning from FIRST_DEVICE_VECTOR+8). This could avoid the vectors are used up with enough module inserting and removing Cc: Eric W. Biedierman Cc: Muli Ben-Yehuda Signed-off-By: Yinghai Lu Signed-off-by: Andi Kleen --- arch/x86_64/kernel/io_apic.c | 18 +++++++++++++++++- 1 files changed, 17 insertions(+), 1 deletion(-) Index: linux/arch/x86_64/kernel/io_apic.c =================================================================== --- linux.orig/arch/x86_64/kernel/io_apic.c +++ linux/arch/x86_64/kernel/io_apic.c @@ -684,6 +684,22 @@ static int assign_irq_vector(int irq, cp return vector; } +static void __clear_irq_vector(int irq) +{ + cpumask_t mask; + int cpu, vector; + + BUG_ON(!irq_vector[irq]); + + vector = irq_vector[irq]; + cpus_and(mask, irq_domain[irq], cpu_online_map); + for_each_cpu_mask(cpu, mask) + per_cpu(vector_irq, cpu)[vector] = -1; + + irq_vector[irq] = 0; + irq_domain[irq] = CPU_MASK_NONE; +} + void __setup_vector_irq(int cpu) { /* Initialize vector_irq on a new cpu */ @@ -1771,7 +1787,7 @@ void destroy_irq(unsigned int irq) dynamic_irq_cleanup(irq); spin_lock_irqsave(&vector_lock, flags); - irq_vector[irq] = 0; + __clear_irq_vector(irq); spin_unlock_irqrestore(&vector_lock, flags); }