From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932244AbaA1Vxf (ORCPT ); Tue, 28 Jan 2014 16:53:35 -0500 Received: from aserp1040.oracle.com ([141.146.126.69]:18984 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932174AbaA1Vx0 (ORCPT ); Tue, 28 Jan 2014 16:53:26 -0500 From: Yinghai Lu To: Ingo Molnar , "H. Peter Anvin" Cc: Thomas Gleixner , Prarit Bhargava , linux-kernel@vger.kernel.org, Yinghai Lu Subject: [PATCH v3] x86, irq: get correct available vectors for cpu disable Date: Tue, 28 Jan 2014 13:54:05 -0800 Message-Id: <1390946045-2769-1-git-send-email-yinghai@kernel.org> X-Mailer: git-send-email 1.8.4 X-Source-IP: acsinet21.oracle.com [141.146.126.237] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org used_vectors is a bitmap for vectors that are not tracked in per_cpu vector_irq. used_vectors contains information on the first 32 exceptions, the system vectors. the IA32_SYSCALL_VECTOR (0x80), and the IRQ_MOVE_CLEANUP_VECTOR (0x20). assign_irq_vectors() assigns vectors up to first_system_vector and it will not use vectors that are set used_vectors. This patch modifies the code to scan up to first_system_vector and do a test on the used_vectors bitmap. So count avaiable vectors correctly. -v2: fix compiling problem. -v3: update changelog and commets Signed-off-by: Yinghai Lu --- arch/x86/kernel/irq.c | 18 ++++++++++++++++-- 1 file changed, 16 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 #include #include +#include #define CREATE_TRACE_POINTS #include @@ -321,8 +322,21 @@ 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 scan per_cpu vectors from + * FIRST_EXTERNAL_VECTOR to first_system_vector. + * It aslo skip vectors that are set in used_vectors bitmask. + * used_vectors could have bits set for + * IA32_SYSCALL_VECTOR (0x80) + * IRQ_MOVE_CLEANUP_VECTOR (0x20) + * Don't count those as available vectors. + */ + 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++; }