From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754821AbbISDID (ORCPT ); Fri, 18 Sep 2015 23:08:03 -0400 Received: from szxga03-in.huawei.com ([119.145.14.66]:37531 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754622AbbISDHj (ORCPT ); Fri, 18 Sep 2015 23:07:39 -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 v5 2/4] genirq: add irq_migrate_all_off_this_cpu() for cpu hotplug Date: Sat, 19 Sep 2015 11:05:57 +0800 Message-ID: <1442631959-10228-3-git-send-email-yangyingliang@huawei.com> X-Mailer: git-send-email 1.9.5.msysgit.1 In-Reply-To: <1442631959-10228-1-git-send-email-yangyingliang@huawei.com> References: <1442631959-10228-1-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 X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020202.55FCD12F.003A,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2013-05-26 15:14:31, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: a239a59e8adc221631a8cecfc0355787 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add irq_migrate_all_off_this_cpu() 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 | 2 ++ kernel/irq/migration.c | 64 ++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 66 insertions(+) diff --git a/include/linux/irq.h b/include/linux/irq.h index 6f8b340..c111fa1 100644 --- a/include/linux/irq.h +++ b/include/linux/irq.h @@ -438,6 +438,8 @@ extern int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *cpumask, bool force); extern int irq_set_vcpu_affinity(unsigned int irq, void *vcpu_info); +extern void irq_migrate_all_off_this_cpu(void); + #if defined(CONFIG_SMP) && defined(CONFIG_GENERIC_PENDING_IRQ) void irq_move_irq(struct irq_data *data); void irq_move_masked_irq(struct irq_data *data); diff --git a/kernel/irq/migration.c b/kernel/irq/migration.c index 1ff2b77..6e3e38d 100644 --- a/kernel/irq/migration.c +++ b/kernel/irq/migration.c @@ -1,6 +1,7 @@ #include #include +#include #include "internals.h" @@ -79,3 +80,66 @@ void irq_move_irq(struct irq_data *idata) idata->chip->irq_unmask(idata); } #endif + +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 irq_migrate_all_off_this_cpu(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); +} -- 2.5.0