From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753087AbbIQFUl (ORCPT ); Thu, 17 Sep 2015 01:20:41 -0400 Received: from szxga01-in.huawei.com ([58.251.152.64]:15941 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751800AbbIQFUk (ORCPT ); Thu, 17 Sep 2015 01:20:40 -0400 From: Yang Yingliang To: , CC: Yang Yingliang , Jiang Liu , Thomas Gleixner , "Marc Zyngier" , Mark Rutland , "Will Deacon" , Russell King - ARM Linux , Hanjun Guo Subject: [RFC PATCH v4 2/4] genirq: add move_irqs() for cpu hotplug Date: Thu, 17 Sep 2015 13:19:24 +0800 Message-ID: <1442467166-1460-3-git-send-email-yangyingliang@huawei.com> X-Mailer: git-send-email 1.9.5.msysgit.1 In-Reply-To: <1442467166-1460-1-git-send-email-yangyingliang@huawei.com> References: <1442467166-1460-1-git-send-email-yangyingliang@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.177.19.219] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add move_irqs() into kernel/irq/migration.c. So we can use it to migrate interrupts, when cpu is offline. Cc: Jiang Liu Cc: Thomas Gleixner Cc: Marc Zyngier Cc: Mark Rutland Cc: Will Deacon Cc: Russell King - ARM Linux Cc: Hanjun Guo Signed-off-by: Yang Yingliang --- include/linux/irq.h | 4 +++ kernel/irq/migration.c | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 70 insertions(+) diff --git a/include/linux/irq.h b/include/linux/irq.h index 6f8b340..64e3a02 100644 --- a/include/linux/irq.h +++ b/include/linux/irq.h @@ -446,6 +446,10 @@ static inline void irq_move_irq(struct irq_data *data) { } static inline void irq_move_masked_irq(struct irq_data *data) { } #endif +#if defined(CONFIG_SMP) && defined(CONFIG_GENERIC_IRQ_MIGRATION) && defined(CONFIG_HOTPLUG_CPU) +void move_irqs(void); +#endif + extern int no_irq_affinity; #ifdef CONFIG_HARDIRQS_SW_RESEND diff --git a/kernel/irq/migration.c b/kernel/irq/migration.c index 1ff2b77..75bff60 100644 --- a/kernel/irq/migration.c +++ b/kernel/irq/migration.c @@ -1,6 +1,7 @@ #include #include +#include #include "internals.h" @@ -79,3 +80,68 @@ void irq_move_irq(struct irq_data *idata) idata->chip->irq_unmask(idata); } #endif + +#ifdef CONFIG_HOTPLUG_CPU +static bool migrate_one_irq(struct irq_desc *desc) +{ + struct irq_data *d = irq_desc_get_irq_data(desc); + const struct cpumask *affinity = d->affinity; + struct irq_chip *c; + bool ret = false; + + /* + * If this is a per-CPU interrupt, or the affinity does not + * include this CPU, then we have nothing to do. + */ + if (irqd_is_per_cpu(d) || !cpumask_test_cpu(smp_processor_id(), affinity)) + return false; + + if (cpumask_any_and(affinity, cpu_online_mask) >= nr_cpu_ids) { + affinity = cpu_online_mask; + ret = true; + } + + c = irq_data_get_irq_chip(d); + if (!c->irq_set_affinity) { + pr_warn_ratelimited("IRQ%u: unable to set affinity\n", d->irq); + } else { + int r = irq_do_set_affinity(d, affinity, false); + if (r) + pr_warn_ratelimited("IRQ%u: set affinity failed(%d).\n", d->irq, r); + } + + return ret; +} + +/* + * The current CPU has been marked offline. Migrate IRQs off this CPU. + * If the affinity settings do not allow other CPUs, force them onto any + * available CPU. + * + * Note: we must iterate over all IRQs, whether they have an attached + * action structure or not, as we need to get chained interrupts too. + */ +void move_irqs(void) +{ + unsigned int irq; + struct irq_desc *desc; + unsigned long flags; + + local_irq_save(flags); + + for_each_active_irq(irq) { + bool affinity_broken; + + desc = irq_to_desc(irq); + raw_spin_lock(&desc->lock); + affinity_broken = migrate_one_irq(desc); + raw_spin_unlock(&desc->lock); + + if (affinity_broken) + pr_warn_ratelimited("IRQ%u no longer affine to CPU%u\n", + irq, smp_processor_id()); + } + + local_irq_restore(flags); +} +#endif /* CONFIG_HOTPLUG_CPU */ -- 2.5.0