Patchwork [v3,32/45] blackfin/smp: Use get/put_online_cpus_atomic() to prevent CPU offline

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Submitter Srivatsa S. Bhat
Date June 27, 2013, 7:58 p.m.
Message ID <>
Download mbox | patch
Permalink /patch/255164/
State Not Applicable
Delegated to: David Miller
Headers show


Srivatsa S. Bhat - June 27, 2013, 7:58 p.m.
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: Mike Frysinger <>
Cc: Bob Liu <>
Cc: Steven Miao <>
Cc: Thomas Gleixner <>
Signed-off-by: Srivatsa S. Bhat <>

 arch/blackfin/mach-common/smp.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

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diff --git a/arch/blackfin/mach-common/smp.c b/arch/blackfin/mach-common/smp.c
index 1bc2ce6..11496cd 100644
--- a/arch/blackfin/mach-common/smp.c
+++ b/arch/blackfin/mach-common/smp.c
@@ -238,13 +238,13 @@  void smp_send_stop(void)
 	cpumask_t callmap;
-	preempt_disable();
+	get_online_cpus_atomic();
 	cpumask_copy(&callmap, cpu_online_mask);
 	cpumask_clear_cpu(smp_processor_id(), &callmap);
 	if (!cpumask_empty(&callmap))
 		send_ipi(&callmap, BFIN_IPI_CPU_STOP);
-	preempt_enable();
+	put_online_cpus_atomic();