From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Srivatsa S. Bhat" Subject: [PATCH v2 33/45] cris/smp: Use get/put_online_cpus_atomic() to prevent CPU offline Date: Wed, 26 Jun 2013 02:01:51 +0530 Message-ID: <20130625203151.16593.6198.stgit@srivatsabhat.in.ibm.com> References: <20130625202452.16593.22810.stgit@srivatsabhat.in.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20130625202452.16593.22810.stgit@srivatsabhat.in.ibm.com> Sender: linux-kernel-owner@vger.kernel.org To: 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 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, Jesper Nilsson , Mikael Starvik , Thomas Gleixner , linux-cris-kernel@axis.com"Srivatsa S. Bhat" List-Id: linux-pm@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. Acked-by: Jesper Nilsson Cc: Mikael Starvik Cc: Thomas Gleixner Cc: linux-cris-kernel@axis.com Signed-off-by: Srivatsa S. Bhat --- arch/cris/arch-v32/kernel/smp.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/cris/arch-v32/kernel/smp.c b/arch/cris/arch-v32/kernel/smp.c index cdd1202..b2d4612 100644 --- a/arch/cris/arch-v32/kernel/smp.c +++ b/arch/cris/arch-v32/kernel/smp.c @@ -13,6 +13,7 @@ #include #include #include +#include #include #include #include @@ -222,6 +223,7 @@ void flush_tlb_common(struct mm_struct* mm, struct vm_area_struct* vma, unsigned unsigned long flags; cpumask_t cpu_mask; + get_online_cpus_atomic(); spin_lock_irqsave(&tlbstate_lock, flags); cpu_mask = (mm == FLUSH_ALL ? cpu_all_mask : *mm_cpumask(mm)); cpumask_clear_cpu(smp_processor_id(), &cpu_mask); @@ -230,6 +232,7 @@ void flush_tlb_common(struct mm_struct* mm, struct vm_area_struct* vma, unsigned flush_addr = addr; send_ipi(IPI_FLUSH_TLB, 1, cpu_mask); spin_unlock_irqrestore(&tlbstate_lock, flags); + put_online_cpus_atomic(); } void flush_tlb_all(void) @@ -319,10 +322,12 @@ int smp_call_function(void (*func)(void *info), void *info, int wait) data.info = info; data.wait = wait; + get_online_cpus_atomic(); spin_lock(&call_lock); call_data = &data; ret = send_ipi(IPI_CALL, wait, cpu_mask); spin_unlock(&call_lock); + put_online_cpus_atomic(); return ret; }