This variable is beyond pointless. Nothing allocates a vector via alloc_gate() below FIRST_SYSTEM_VECTOR. So nothing can change first_system_vector. If there is a need for a gate below FIRST_SYSTEM_VECTOR then it can be added to the vector defines and FIRST_SYSTEM_VECTOR adjusted accordingly. Signed-off-by: Thomas Gleixner --- arch/x86/include/asm/desc.h | 11 ++--------- arch/x86/kernel/apic/apic.c | 2 -- arch/x86/kernel/apic/vector.c | 2 +- arch/x86/kernel/idt.c | 2 +- arch/x86/kernel/irq.c | 2 +- 5 files changed, 5 insertions(+), 14 deletions(-) --- a/arch/x86/include/asm/desc.h +++ b/arch/x86/include/asm/desc.h @@ -408,21 +408,14 @@ static inline void set_intr_gate(unsigne _set_gate(n, GATE_INTERRUPT, addr, 0, 0, __KERNEL_CS); } -#ifdef CONFIG_X86_LOCAL_APIC -extern int first_system_vector; -#else -#define first_system_vector NR_VECTORS -#endif - /* used_vectors is BITMAP for irq is not managed by percpu vector_irq */ extern unsigned long used_vectors[]; -static inline void alloc_system_vector(int vector) +static inline void alloc_system_vector(unsigned int vector) { + BUG_ON(vector < FIRST_SYSTEM_VECTOR); if (!test_bit(vector, used_vectors)) { set_bit(vector, used_vectors); - if (first_system_vector > vector) - first_system_vector = vector; } else { BUG(); } --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -177,8 +177,6 @@ static int disable_apic_timer __initdata int local_apic_timer_c2_ok; EXPORT_SYMBOL_GPL(local_apic_timer_c2_ok); -int first_system_vector = FIRST_SYSTEM_VECTOR; - /* * Debug level, exported for io_apic.c */ --- a/arch/x86/kernel/apic/vector.c +++ b/arch/x86/kernel/apic/vector.c @@ -166,7 +166,7 @@ static int __assign_irq_vector(int irq, offset = current_offset; next: vector += 16; - if (vector >= first_system_vector) { + if (vector >= FIRST_SYSTEM_VECTOR) { offset = (offset + 1) % 16; vector = FIRST_EXTERNAL_VECTOR + offset; } --- a/arch/x86/kernel/idt.c +++ b/arch/x86/kernel/idt.c @@ -290,7 +290,7 @@ void __init idt_setup_apic_and_irq_gates idt_setup_from_table(idt_table, apic_idts, ARRAY_SIZE(apic_idts)); - for_each_clear_bit_from(i, used_vectors, first_system_vector) { + for_each_clear_bit_from(i, used_vectors, FIRST_SYSTEM_VECTOR) { entry = irq_entries_start + 8 * (i - FIRST_EXTERNAL_VECTOR); set_intr_gate(i, entry); } --- a/arch/x86/kernel/irq.c +++ b/arch/x86/kernel/irq.c @@ -414,7 +414,7 @@ int check_irq_vectors_for_cpu_disable(vo * this w/o holding vector_lock. */ for (vector = FIRST_EXTERNAL_VECTOR; - vector < first_system_vector; vector++) { + vector < FIRST_SYSTEM_VECTOR; vector++) { if (!test_bit(vector, used_vectors) && IS_ERR_OR_NULL(per_cpu(vector_irq, cpu)[vector])) { if (++count == this_count)