From patchwork Tue Jan 22 07:38:00 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Srivatsa S. Bhat" X-Patchwork-Id: 2016471 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by patchwork1.kernel.org (Postfix) with ESMTP id 55D463FCDE for ; Tue, 22 Jan 2013 07:47:49 +0000 (UTC) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1TxYXY-00082O-56; Tue, 22 Jan 2013 07:45:04 +0000 Received: from e23smtp02.au.ibm.com ([202.81.31.144]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1TxYSh-0003yp-2d for linux-arm-kernel@lists.infradead.org; Tue, 22 Jan 2013 07:40:04 +0000 Received: from /spool/local by e23smtp02.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 22 Jan 2013 17:34:43 +1000 Received: from d23dlp01.au.ibm.com (202.81.31.203) by e23smtp02.au.ibm.com (202.81.31.208) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Tue, 22 Jan 2013 17:34:42 +1000 Received: from d23relay04.au.ibm.com (d23relay04.au.ibm.com [9.190.234.120]) by d23dlp01.au.ibm.com (Postfix) with ESMTP id 1CDB52CE804A for ; Tue, 22 Jan 2013 18:39:58 +1100 (EST) Received: from d23av03.au.ibm.com (d23av03.au.ibm.com [9.190.234.97]) by d23relay04.au.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r0M7SCjS2490788 for ; Tue, 22 Jan 2013 18:28:12 +1100 Received: from d23av03.au.ibm.com (loopback [127.0.0.1]) by d23av03.au.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r0M7dud8012415 for ; Tue, 22 Jan 2013 18:39:57 +1100 Received: from srivatsabhat.in.ibm.com (srivatsabhat.in.ibm.com [9.124.35.112]) by d23av03.au.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id r0M7djLk012217; Tue, 22 Jan 2013 18:39:46 +1100 From: "Srivatsa S. Bhat" Subject: [PATCH v5 18/45] 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 Date: Tue, 22 Jan 2013 13:08:00 +0530 Message-ID: <20130122073757.13822.33489.stgit@srivatsabhat.in.ibm.com> In-Reply-To: <20130122073210.13822.50434.stgit@srivatsabhat.in.ibm.com> References: <20130122073210.13822.50434.stgit@srivatsabhat.in.ibm.com> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13012207-5490-0000-0000-000002DB2E02 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130122_024003_603698_15C9EA49 X-CRM114-Status: GOOD ( 13.23 ) X-Spam-Score: -1.9 (-) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-1.9 points) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at http://www.dnswl.org/, medium trust [202.81.31.144 listed in list.dnswl.org] 3.0 KHOP_BIG_TO_CC Sent to 10+ recipients instaed of Bcc or a list -0.7 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: linux-arch@vger.kernel.org, linux@arm.linux.org.uk, nikunj@linux.vnet.ibm.com, linux-pm@vger.kernel.org, fweisbec@gmail.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, rostedt@goodmis.org, xiaoguangrong@linux.vnet.ibm.com, rjw@sisk.pl, sbw@mit.edu, wangyun@linux.vnet.ibm.com, srivatsa.bhat@linux.vnet.ibm.com, netdev@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.14 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 Once stop_machine() is gone from the CPU offline path, we won't be able to depend on preempt_disable() or local_irq_disable() 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. Signed-off-by: Srivatsa S. Bhat --- kernel/irq/manage.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index e49a288..b4240b9 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -16,6 +16,7 @@ #include #include #include +#include #include #include "internals.h" @@ -202,7 +203,9 @@ int irq_set_affinity(unsigned int irq, const struct cpumask *mask) return -EINVAL; raw_spin_lock_irqsave(&desc->lock, flags); + get_online_cpus_atomic(); ret = __irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask); + put_online_cpus_atomic(); raw_spin_unlock_irqrestore(&desc->lock, flags); return ret; } @@ -343,7 +346,9 @@ int irq_select_affinity_usr(unsigned int irq, struct cpumask *mask) int ret; raw_spin_lock_irqsave(&desc->lock, flags); + get_online_cpus_atomic(); ret = setup_affinity(irq, desc, mask); + put_online_cpus_atomic(); raw_spin_unlock_irqrestore(&desc->lock, flags); return ret; } @@ -1126,7 +1131,9 @@ __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;