assign_irq_vector will stop before first_system_vector. also it will not vector that is set in used_vectors.
used_vectors is used to track non per_cpu irq_vector in vector_irq. It include first 32 exception [0,1f) and system vector near 0xfe. and IA32_SYSCALL_VECTOR (0x80), IRQ_MOVE_CLEANUP_VECTOR (0x20). So add checking for them for counting avaiable vectors. -v2: fix compiling problem. Signed-off-by: Yinghai Lu <ying...@kernel.org> --- arch/x86/kernel/irq.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) Index: linux-2.6/arch/x86/kernel/irq.c =================================================================== --- linux-2.6.orig/arch/x86/kernel/irq.c +++ linux-2.6/arch/x86/kernel/irq.c @@ -17,6 +17,7 @@ #include <asm/idle.h> #include <asm/mce.h> #include <asm/hw_irq.h> +#include <asm/desc.h> #define CREATE_TRACE_POINTS #include <asm/trace/irq_vectors.h> @@ -321,8 +322,19 @@ int check_irq_vectors_for_cpu_disable(vo for_each_online_cpu(cpu) { if (cpu == this_cpu) continue; - for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS; - vector++) { + + /* + * assign_irq_vector() only use vector under + * first_system_vector and not set in used_vectors bitmask. + * used_vectors could have bits set for + * IA32_SYSCALL_VECTOR (0x80) + * IRQ_MOVE_CLEANUP_VECTOR (0x20) + */ + for (vector = FIRST_EXTERNAL_VECTOR; + vector < first_system_vector; vector++) { + if (test_bit(vector, used_vectors)) + continue; + if (per_cpu(vector_irq, cpu)[vector] < 0) count++; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/