From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e28smtp06.in.ibm.com (e28smtp06.in.ibm.com [122.248.162.6]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e28smtp06.in.ibm.com", Issuer "GeoTrust SSL CA" (not verified)) by ozlabs.org (Postfix) with ESMTPS id E5F3E2C0C0C for ; Sun, 23 Jun 2013 23:45:48 +1000 (EST) Received: from /spool/local by e28smtp06.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Sun, 23 Jun 2013 19:08:23 +0530 Received: from d28relay05.in.ibm.com (d28relay05.in.ibm.com [9.184.220.62]) by d28dlp03.in.ibm.com (Postfix) with ESMTP id 466D81258053 for ; Sun, 23 Jun 2013 19:14:46 +0530 (IST) Received: from d28av05.in.ibm.com (d28av05.in.ibm.com [9.184.220.67]) by d28relay05.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r5NDjfb429098194 for ; Sun, 23 Jun 2013 19:15:41 +0530 Received: from d28av05.in.ibm.com (loopback [127.0.0.1]) by d28av05.in.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r5NDjh0O024286 for ; Sun, 23 Jun 2013 23:45:44 +1000 From: "Srivatsa S. Bhat" Subject: [PATCH 19/45] irq: Use get/put_online_cpus_atomic() to prevent CPU offline To: tglx@linutronix.de, peterz@infradead.org, tj@kernel.org, oleg@redhat.com, paulmck@linux.vnet.ibm.com, rusty@rustcorp.com.au, mingo@kernel.org, akpm@linux-foundation.org, namhyung@kernel.org, walken@google.com, vincent.guittot@linaro.org, laijs@cn.fujitsu.com Date: Sun, 23 Jun 2013 19:12:30 +0530 Message-ID: <20130623134226.19094.55366.stgit@srivatsabhat.in.ibm.com> In-Reply-To: <20130623133642.19094.16038.stgit@srivatsabhat.in.ibm.com> References: <20130623133642.19094.16038.stgit@srivatsabhat.in.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Cc: linux-arch@vger.kernel.org, nikunj@linux.vnet.ibm.com, zhong@linux.vnet.ibm.com, linux-pm@vger.kernel.org, fweisbec@gmail.com, linux-kernel@vger.kernel.org, rostedt@goodmis.org, xiaoguangrong@linux.vnet.ibm.com, sbw@mit.edu, wangyun@linux.vnet.ibm.com, srivatsa.bhat@linux.vnet.ibm.com, netdev@vger.kernel.org, Thomas Gleixner , linuxppc-dev@lists.ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Once stop_machine() is gone from the CPU offline path, we won't be able to depend on disabling preemption to prevent CPUs from going offline from under us. Use the get/put_online_cpus_atomic() APIs to prevent CPUs from going offline, while invoking from atomic context. Cc: Thomas Gleixner Signed-off-by: Srivatsa S. Bhat --- kernel/irq/manage.c | 7 +++++++ kernel/irq/proc.c | 3 +++ 2 files changed, 10 insertions(+) diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index e16caa8..4d89f19 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -18,6 +18,7 @@ #include #include #include +#include #include "internals.h" @@ -202,9 +203,11 @@ int irq_set_affinity(unsigned int irq, const struct cpumask *mask) if (!desc) return -EINVAL; + get_online_cpus_atomic(); raw_spin_lock_irqsave(&desc->lock, flags); ret = __irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask); raw_spin_unlock_irqrestore(&desc->lock, flags); + put_online_cpus_atomic(); return ret; } @@ -343,9 +346,11 @@ int irq_select_affinity_usr(unsigned int irq, struct cpumask *mask) unsigned long flags; int ret; + get_online_cpus_atomic(); raw_spin_lock_irqsave(&desc->lock, flags); ret = setup_affinity(irq, desc, mask); raw_spin_unlock_irqrestore(&desc->lock, flags); + put_online_cpus_atomic(); return ret; } @@ -1128,7 +1133,9 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) } /* Set default affinity mask once everything is setup */ + get_online_cpus_atomic(); setup_affinity(irq, desc, mask); + put_online_cpus_atomic(); } else if (new->flags & IRQF_TRIGGER_MASK) { unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK; diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c index 19ed5c4..47f9a74 100644 --- a/kernel/irq/proc.c +++ b/kernel/irq/proc.c @@ -7,6 +7,7 @@ */ #include +#include #include #include #include @@ -441,6 +442,7 @@ int show_interrupts(struct seq_file *p, void *v) if (!desc) return 0; + get_online_cpus_atomic(); raw_spin_lock_irqsave(&desc->lock, flags); for_each_online_cpu(j) any_count |= kstat_irqs_cpu(i, j); @@ -477,6 +479,7 @@ int show_interrupts(struct seq_file *p, void *v) seq_putc(p, '\n'); out: raw_spin_unlock_irqrestore(&desc->lock, flags); + put_online_cpus_atomic(); return 0; } #endif