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Bhat" Subject: [PATCH v5 30/45] alpha/smp: 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 13:11:18 +0530 Message-ID: <20130122074113.13822.3018.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: 13012207-2674-0000-0000-0000078F640A X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130122_024311_913856_7528B26C X-CRM114-Status: GOOD ( 11.99 ) 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 [122.248.162.9 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. Also, remove the non-ASCII character present in this file! Cc: linux-alpha@vger.kernel.org Signed-off-by: Srivatsa S. Bhat --- arch/alpha/kernel/smp.c | 19 +++++++++---------- 1 file changed, 9 insertions(+), 10 deletions(-) diff --git a/arch/alpha/kernel/smp.c b/arch/alpha/kernel/smp.c index 9603bc2..9213d5d 100644 --- a/arch/alpha/kernel/smp.c +++ b/arch/alpha/kernel/smp.c @@ -498,7 +498,6 @@ smp_cpus_done(unsigned int max_cpus) ((bogosum + 2500) / (5000/HZ)) % 100); } - void smp_percpu_timer_interrupt(struct pt_regs *regs) { @@ -682,7 +681,7 @@ ipi_flush_tlb_mm(void *x) void flush_tlb_mm(struct mm_struct *mm) { - preempt_disable(); + get_online_cpus_atomic(); if (mm == current->active_mm) { flush_tlb_current(mm); @@ -694,7 +693,7 @@ flush_tlb_mm(struct mm_struct *mm) if (mm->context[cpu]) mm->context[cpu] = 0; } - preempt_enable(); + put_online_cpus_atomic(); return; } } @@ -703,7 +702,7 @@ flush_tlb_mm(struct mm_struct *mm) printk(KERN_CRIT "flush_tlb_mm: timed out\n"); } - preempt_enable(); + put_online_cpus_atomic(); } EXPORT_SYMBOL(flush_tlb_mm); @@ -731,7 +730,7 @@ flush_tlb_page(struct vm_area_struct *vma, unsigned long addr) struct flush_tlb_page_struct data; struct mm_struct *mm = vma->vm_mm; - preempt_disable(); + get_online_cpus_atomic(); if (mm == current->active_mm) { flush_tlb_current_page(mm, vma, addr); @@ -743,7 +742,7 @@ flush_tlb_page(struct vm_area_struct *vma, unsigned long addr) if (mm->context[cpu]) mm->context[cpu] = 0; } - preempt_enable(); + put_online_cpus_atomic(); return; } } @@ -756,7 +755,7 @@ flush_tlb_page(struct vm_area_struct *vma, unsigned long addr) printk(KERN_CRIT "flush_tlb_page: timed out\n"); } - preempt_enable(); + put_online_cpus_atomic(); } EXPORT_SYMBOL(flush_tlb_page); @@ -787,7 +786,7 @@ flush_icache_user_range(struct vm_area_struct *vma, struct page *page, if ((vma->vm_flags & VM_EXEC) == 0) return; - preempt_disable(); + get_online_cpus_atomic(); if (mm == current->active_mm) { __load_new_mm_context(mm); @@ -799,7 +798,7 @@ flush_icache_user_range(struct vm_area_struct *vma, struct page *page, if (mm->context[cpu]) mm->context[cpu] = 0; } - preempt_enable(); + put_online_cpus_atomic(); return; } } @@ -808,5 +807,5 @@ flush_icache_user_range(struct vm_area_struct *vma, struct page *page, printk(KERN_CRIT "flush_icache_page: timed out\n"); } - preempt_enable(); + put_online_cpus_atomic(); }