Commit-ID: ac2a55395eddccd6e3e39532df9869d61e97b2ee Gitweb: http://git.kernel.org/tip/ac2a55395eddccd6e3e39532df9869d61e97b2ee Author: Yinghai Lu <ying...@kernel.org> AuthorDate: Tue, 13 May 2014 11:39:34 -0400 Committer: Thomas Gleixner <t...@linutronix.de> CommitDate: Wed, 4 Jun 2014 14:18:34 +0200
x86: irq: Get correct available vectors for cpu disable check_irq_vectors_for_cpu_disable() can overestimate the number of available interrupt vectors, so the check for cpu down succeeds, but the actual cpu removal fails. It iterates from FIRST_EXTERNAL_VECTOR to NR_VECTORS, which is wrong because the systems vectors are not taken into account. Limit the search to first_system_vector instead of NR_VECTORS. The second indicator for vector availability the used_vectors bitmap is not taken into account at all. So system vectors, e.g. IA32_SYSCALL_VECTOR (0x80) and IRQ_MOVE_CLEANUP_VECTOR (0x20), are accounted as available. Add a check for the used_vectors bitmap and do not account vectors which are marked there. [ tglx: Simplified code. Rewrote changelog and code comments. ] Signed-off-by: Yinghai Lu <ying...@kernel.org> Acked-by: Prarit Bhargava <pra...@redhat.com> Cc: Seiji Aguchi <seiji.agu...@hds.com> Cc: Andi Kleen <a...@linux.intel.com> Cc: K. Y. Srinivasan <k...@microsoft.com> Cc: Steven Rostedt (Red Hat) <rost...@goodmis.org> Cc: Ingo Molnar <mi...@redhat.com> Cc: "H. Peter Anvin" <h...@zytor.com> Cc: "Elliott, Robert (Server Storage)" <elli...@hp.com> Cc: x...@kernel.org Link: http://lkml.kernel.org/r/1400160305-17774-2-git-send-email-pra...@redhat.com Signed-off-by: Thomas Gleixner <t...@linutronix.de> --- arch/x86/kernel/irq.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c index 283a76a..11ccfb0 100644 --- a/arch/x86/kernel/irq.c +++ b/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> @@ -334,10 +335,17 @@ int check_irq_vectors_for_cpu_disable(void) for_each_online_cpu(cpu) { if (cpu == this_cpu) continue; - for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS; - vector++) { - if (per_cpu(vector_irq, cpu)[vector] < 0) - count++; + /* + * We scan from FIRST_EXTERNAL_VECTOR to first system + * vector. If the vector is marked in the used vectors + * bitmap or an irq is assigned to it, we don't count + * it as available. + */ + for (vector = FIRST_EXTERNAL_VECTOR; + vector < first_system_vector; vector++) { + if (!test_bit(vector, used_vectors) && + 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/
