From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S938845AbdEALmB (ORCPT ); Mon, 1 May 2017 07:42:01 -0400 Received: from mail-wm0-f47.google.com ([74.125.82.47]:38419 "EHLO mail-wm0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755530AbdEALkF (ORCPT ); Mon, 1 May 2017 07:40:05 -0400 Date: Mon, 1 May 2017 13:40:01 +0200 From: Ingo Molnar To: Linus Torvalds Cc: linux-kernel@vger.kernel.org, Thomas Gleixner , "H. Peter Anvin" , Peter Zijlstra , Andrew Morton Subject: [GIT PULL] x86/irq change for v4.12 Message-ID: <20170501114000.4ognhldpkye25s4l@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Linus, Please pull the latest x86-irq-for-linus git tree from: git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-irq-for-linus # HEAD: c0edbd4a1693600d6eb9e2faad452638c35391f7 x86/irq: Optimize free vector check in the CPU offline path A single commit that micro-optimizes an IRQ vectors code path in the CPU offlining code. Thanks, Ingo ------------------> Chen Yu (1): x86/irq: Optimize free vector check in the CPU offline path arch/x86/kernel/irq.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c index 4d8183b5f113..f34fe7444836 100644 --- a/arch/x86/kernel/irq.c +++ b/arch/x86/kernel/irq.c @@ -394,6 +394,9 @@ int check_irq_vectors_for_cpu_disable(void) !cpumask_subset(&affinity_new, &online_new)) this_count++; } + /* No need to check any further. */ + if (!this_count) + return 0; count = 0; for_each_online_cpu(cpu) { @@ -411,8 +414,10 @@ int check_irq_vectors_for_cpu_disable(void) for (vector = FIRST_EXTERNAL_VECTOR; vector < first_system_vector; vector++) { if (!test_bit(vector, used_vectors) && - IS_ERR_OR_NULL(per_cpu(vector_irq, cpu)[vector])) - count++; + IS_ERR_OR_NULL(per_cpu(vector_irq, cpu)[vector])) { + if (++count == this_count) + return 0; + } } }