Jetpack/kernel/kernel-4.9/rt-patches/0149-hotplug-Use-migrate-di...

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Diff

From 1d2725162f2c8c47f06faa08c051fcca9a9ec6e7 Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Sun, 17 Jul 2011 19:35:29 +0200
Subject: [PATCH 149/352] hotplug: Use migrate disable on unplug
Migration needs to be disabled accross the unplug handling to make
sure that the unplug thread is off the unplugged cpu.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
kernel/cpu.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/kernel/cpu.c b/kernel/cpu.c
index ee08823..3b026a1 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -1103,14 +1103,13 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen,
cpumask_andnot(cpumask, cpu_online_mask, cpumask_of(cpu));
set_cpus_allowed_ptr(current, cpumask);
free_cpumask_var(cpumask);
- preempt_disable();
+ migrate_disable();
mycpu = smp_processor_id();
if (mycpu == cpu) {
printk(KERN_ERR "Yuck! Still on unplug CPU\n!");
- preempt_enable();
+ migrate_enable();
return -EBUSY;
}
- preempt_enable();
cpu_hotplug_begin();
ret = cpu_unplug_begin(cpu);
@@ -1159,6 +1158,7 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen,
cpu_unplug_done(cpu);
out_cancel:
cpu_hotplug_done();
+ migrate_enable();
/* This post dead nonsense must die */
if (!ret && hasdied)
cpu_notify_nofail(CPU_POST_DEAD, cpu);
--
2.7.4