On 01/26/2014 03:50 PM, Yinghai Lu wrote: > 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. >
Yinghai, no objection to the patch ... but how about used_vectors is a bitmap for global irqs; it tracks the non per_cpu irq_vectors in vector_irq. used_vectors contains information on the first 32 exceptions (0 to 0x1f), the system vectors near the first system vector (0xfe), the IA32_SYSCALL_VECTOR (0x80), and the IRQ_MOVE_CLEANUP_VECTOR (0x20) assign_irq_vectors() assigns vectors up to first_system_vector (0xfe) and sets the used_vectors bit for each assigned vector. Currently, the IRQ checking code only scans from the FIRST_EXTERNAL_VECTOR to the end of the vectors. This patch modifies the code to scan to first_system_vector and do a test on the used_vectors bitmap. ... and ... > -v2: fix compiling problem. > > Signed-off-by: Yinghai Lu <[email protected]> > > --- > 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) > + */ + /* + * assign_irq_vector() will only scan non per_cpu vectors from + * FIRST_EXTERNAL_VECTOR to first_system_vector (0xfe) and not + * set in used_vectors bitmask. This takes into account + * the IA32_SYSCALL_VECTOR and the IRQ_MOVE_CLEANUP_VECTOR, + * which should not be counted. + */ ... what do you think? P. > + 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 [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
