From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755095Ab3F0UC2 (ORCPT ); Thu, 27 Jun 2013 16:02:28 -0400 Received: from e23smtp04.au.ibm.com ([202.81.31.146]:33786 "EHLO e23smtp04.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755081Ab3F0UCY (ORCPT ); Thu, 27 Jun 2013 16:02:24 -0400 From: "Srivatsa S. Bhat" Subject: [PATCH v3 35/45] ia64: irq, perfmon: 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, David.Laight@aculab.com Cc: rostedt@goodmis.org, wangyun@linux.vnet.ibm.com, xiaoguangrong@linux.vnet.ibm.com, sbw@mit.edu, fweisbec@gmail.com, zhong@linux.vnet.ibm.com, nikunj@linux.vnet.ibm.com, srivatsa.bhat@linux.vnet.ibm.com, linux-pm@vger.kernel.org, linux-arch@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Tony Luck , Fenghua Yu , Andrew Morton , "Eric W. Biederman" , Thomas Gleixner , linux-ia64@vger.kernel.org, "Srivatsa S. Bhat" Date: Fri, 28 Jun 2013 01:28:44 +0530 Message-ID: <20130627195843.29830.10284.stgit@srivatsabhat.in.ibm.com> In-Reply-To: <20130627195136.29830.10445.stgit@srivatsabhat.in.ibm.com> References: <20130627195136.29830.10445.stgit@srivatsabhat.in.ibm.com> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13062719-9264-0000-0000-000004063882 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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: Tony Luck Cc: Fenghua Yu Cc: Andrew Morton Cc: "Eric W. Biederman" Cc: Thomas Gleixner Cc: linux-ia64@vger.kernel.org Signed-off-by: Srivatsa S. Bhat --- arch/ia64/kernel/irq_ia64.c | 15 +++++++++++++++ arch/ia64/kernel/perfmon.c | 8 +++++++- 2 files changed, 22 insertions(+), 1 deletion(-) diff --git a/arch/ia64/kernel/irq_ia64.c b/arch/ia64/kernel/irq_ia64.c index 1034884..f58b162 100644 --- a/arch/ia64/kernel/irq_ia64.c +++ b/arch/ia64/kernel/irq_ia64.c @@ -25,6 +25,7 @@ #include #include #include +#include #include #include #include @@ -160,9 +161,11 @@ int bind_irq_vector(int irq, int vector, cpumask_t domain) unsigned long flags; int ret; + get_online_cpus_atomic(); spin_lock_irqsave(&vector_lock, flags); ret = __bind_irq_vector(irq, vector, domain); spin_unlock_irqrestore(&vector_lock, flags); + put_online_cpus_atomic(); return ret; } @@ -190,9 +193,11 @@ static void clear_irq_vector(int irq) { unsigned long flags; + get_online_cpus_atomic(); spin_lock_irqsave(&vector_lock, flags); __clear_irq_vector(irq); spin_unlock_irqrestore(&vector_lock, flags); + put_online_cpus_atomic(); } int @@ -204,6 +209,7 @@ ia64_native_assign_irq_vector (int irq) vector = -ENOSPC; + get_online_cpus_atomic(); spin_lock_irqsave(&vector_lock, flags); for_each_online_cpu(cpu) { domain = vector_allocation_domain(cpu); @@ -218,6 +224,7 @@ ia64_native_assign_irq_vector (int irq) BUG_ON(__bind_irq_vector(irq, vector, domain)); out: spin_unlock_irqrestore(&vector_lock, flags); + put_online_cpus_atomic(); return vector; } @@ -302,9 +309,11 @@ int irq_prepare_move(int irq, int cpu) unsigned long flags; int ret; + get_online_cpus_atomic(); spin_lock_irqsave(&vector_lock, flags); ret = __irq_prepare_move(irq, cpu); spin_unlock_irqrestore(&vector_lock, flags); + put_online_cpus_atomic(); return ret; } @@ -320,11 +329,13 @@ void irq_complete_move(unsigned irq) if (unlikely(cpu_isset(smp_processor_id(), cfg->old_domain))) return; + get_online_cpus_atomic(); cpumask_and(&cleanup_mask, &cfg->old_domain, cpu_online_mask); cfg->move_cleanup_count = cpus_weight(cleanup_mask); for_each_cpu_mask(i, cleanup_mask) platform_send_ipi(i, IA64_IRQ_MOVE_VECTOR, IA64_IPI_DM_INT, 0); cfg->move_in_progress = 0; + put_online_cpus_atomic(); } static irqreturn_t smp_irq_move_cleanup_interrupt(int irq, void *dev_id) @@ -393,10 +404,12 @@ void destroy_and_reserve_irq(unsigned int irq) dynamic_irq_cleanup(irq); + get_online_cpus_atomic(); spin_lock_irqsave(&vector_lock, flags); __clear_irq_vector(irq); irq_status[irq] = IRQ_RSVD; spin_unlock_irqrestore(&vector_lock, flags); + put_online_cpus_atomic(); } /* @@ -409,6 +422,7 @@ int create_irq(void) cpumask_t domain = CPU_MASK_NONE; irq = vector = -ENOSPC; + get_online_cpus_atomic(); spin_lock_irqsave(&vector_lock, flags); for_each_online_cpu(cpu) { domain = vector_allocation_domain(cpu); @@ -424,6 +438,7 @@ int create_irq(void) BUG_ON(__bind_irq_vector(irq, vector, domain)); out: spin_unlock_irqrestore(&vector_lock, flags); + put_online_cpus_atomic(); if (irq >= 0) dynamic_irq_init(irq); return irq; diff --git a/arch/ia64/kernel/perfmon.c b/arch/ia64/kernel/perfmon.c index 9ea25fc..16c8303 100644 --- a/arch/ia64/kernel/perfmon.c +++ b/arch/ia64/kernel/perfmon.c @@ -6476,9 +6476,12 @@ pfm_install_alt_pmu_interrupt(pfm_intr_handler_desc_t *hdl) /* do the easy test first */ if (pfm_alt_intr_handler) return -EBUSY; + get_online_cpus_atomic(); + /* one at a time in the install or remove, just fail the others */ if (!spin_trylock(&pfm_alt_install_check)) { - return -EBUSY; + ret = -EBUSY; + goto out; } /* reserve our session */ @@ -6498,6 +6501,7 @@ pfm_install_alt_pmu_interrupt(pfm_intr_handler_desc_t *hdl) pfm_alt_intr_handler = hdl; spin_unlock(&pfm_alt_install_check); + put_online_cpus_atomic(); return 0; @@ -6510,6 +6514,8 @@ cleanup_reserve: } spin_unlock(&pfm_alt_install_check); +out: + put_online_cpus_atomic(); return ret; }