From patchwork Thu Jul 21 15:25:35 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Russell King - ARM Linux X-Patchwork-Id: 995552 Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by demeter2.kernel.org (8.14.4/8.14.4) with ESMTP id p6LFRs94009264 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Thu, 21 Jul 2011 15:28:15 GMT Received: from canuck.infradead.org ([2001:4978:20e::1]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1Qjv9n-0008Am-Hg; Thu, 21 Jul 2011 15:27:24 +0000 Received: from localhost ([127.0.0.1] helo=canuck.infradead.org) by canuck.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1Qjv9m-000734-D5; Thu, 21 Jul 2011 15:27:22 +0000 Received: from [2002:4e20:1eda::1] (helo=caramon.arm.linux.org.uk) by canuck.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1Qjv88-0006Xn-7r for linux-arm-kernel@lists.infradead.org; Thu, 21 Jul 2011 15:25:42 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=arm.linux.org.uk; s=caramon; h=Date:Sender:Message-Id:Content-Type:MIME-Version:Cc:Subject:Cc:To:From:References:In-Reply-To; bh=Sz/mINVlmegJ1g1RYRhtD42TZrif5nCEB661zs/yZgs=; b=lx26UHihbNhNX8FZHV3vL08SxM6S+bq5pdm1IoYhP+DYCrq/Y41jTyGm9eVx0L92nl0y1nPWvytq7heiCy/PiS0w+PQClZ1btyRFz9ffSMkOjbcIljp7GwVkj1CpttzIDbpNMJB1ojTaMbzWV28Z5D7kCAIhT6KQVH+vueT9Hfw=; Received: from e0022681537dd.dyn.arm.linux.org.uk ([2002:4e20:1eda:1:222:68ff:fe15:37dd] helo=rmk-PC.arm.linux.org.uk) by caramon.arm.linux.org.uk with esmtpsa (TLSv1:AES256-SHA:256) (Exim 4.72) (envelope-from ) id 1Qjv84-00043e-PQ; Thu, 21 Jul 2011 16:25:37 +0100 Received: from rmk by rmk-PC.arm.linux.org.uk with local (Exim 4.76) (envelope-from ) id 1Qjv83-0003Ie-Ui; Thu, 21 Jul 2011 16:25:35 +0100 In-Reply-To: <20110721151413.GD28942@n2100.arm.linux.org.uk> References: <20110721151413.GD28942@n2100.arm.linux.org.uk> From: Russell King - ARM Linux To: linux-arm-kernel@lists.infradead.org Subject: [PATCH 4/4] ARM: CPU hotplug: ensure we migrate all IRQs off a downed CPU MIME-Version: 1.0 Content-Disposition: inline Message-Id: Date: Thu, 21 Jul 2011 16:25:35 +0100 X-CRM114-Version: 20090807-BlameThorstenAndJenny ( TRE 0.7.6 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20110721_112541_017409_D3231B2A X-CRM114-Status: GOOD ( 17.27 ) X-Spam-Score: 1.2 (+) X-Spam-Report: SpamAssassin version 3.3.1 on canuck.infradead.org summary: Content analysis details: (1.2 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature 1.3 RDNS_NONE Delivered to internal network by a host with no rDNS 0.0 TO_NO_BRKTS_NORDNS To: misformatted and no rDNS Cc: Thomas Gleixner , Santosh Shilimkar X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter2.kernel.org [140.211.167.43]); Thu, 21 Jul 2011 15:28:15 +0000 (UTC) Our selection of interrupts to consider for IRQ migration is sub- standard. We were potentially including per-CPU interrupts in our migration strategy, but omitting chained interrupts. This caused some interrupts to remain on a downed CPU. We were also trying to migrate interrupts which were not migratable, resulting in an OOPS. Instead, iterate over all interrupts, skipping per-CPU interrupts or interrupts whose affinity does not include the downed CPU, and attempt to set the affinity for every one else if their chip implements irq_set_affinity(). Signed-off-by: Russell King --- arch/arm/kernel/irq.c | 39 ++++++++++++++++++++++++++++----------- 1 files changed, 28 insertions(+), 11 deletions(-) diff --git a/arch/arm/kernel/irq.c b/arch/arm/kernel/irq.c index ab63c05..0f928a1 100644 --- a/arch/arm/kernel/irq.c +++ b/arch/arm/kernel/irq.c @@ -131,46 +131,63 @@ int __init arch_probe_nr_irqs(void) #ifdef CONFIG_HOTPLUG_CPU -static bool migrate_one_irq(struct irq_data *d) +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; + affinity = cpu_online_mask; ret = true; } - d->chip->irq_set_affinity(d, affinity, true); + c = irq_data_get_irq_chip(d); + if (c->irq_set_affinity) + c->irq_set_affinity(d, affinity, true); + else + pr_debug("IRQ%u: unable to set affinity\n", d->irq); return ret; } /* - * The CPU has been marked offline. Migrate IRQs off this CPU. If - * the affinity settings do not allow other CPUs, force them onto any + * 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 migrate_irqs(void) { - unsigned int i, cpu = smp_processor_id(); + unsigned int i; struct irq_desc *desc; unsigned long flags; local_irq_save(flags); for_each_irq_desc(i, desc) { - struct irq_data *d = &desc->irq_data; bool affinity_broken = false; + if (!desc) + continue; + raw_spin_lock(&desc->lock); - if (desc->action != NULL && - cpumask_test_cpu(smp_processor_id(), d->affinity)) - affinity_broken = migrate_one_irq(d); + affinity_broken = migrate_one_irq(desc); raw_spin_unlock(&desc->lock); if (affinity_broken && printk_ratelimit()) - pr_warning("IRQ%u no longer affine to CPU%u\n", i, cpu); + pr_warning("IRQ%u no longer affine to CPU%u\n", i, + smp_processor_id()); } local_irq_restore(flags);