From: Thomas Gleixner <tglx@linutronix.de>
Date: Tue, 29 May 2018 19:05:25 +0200
Subject: cpu/hotplug: Make bringup/teardown of smp threads symmetric
Git-commit: c4de65696d865c225fda3b9913b31284ea65ea96
Patch-mainline: v4.19-rc1
References: bsc#1089343

The asymmetry caused a warning to trigger if the bootup was stopped in state
CPUHP_AP_ONLINE_IDLE. The warning no longer triggers as kthread_park() can
now be invoked on already or still parked threads. But there is still no
reason to have this be asymmetric.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Borislav Petkov <bp@suse.de>
---
 kernel/cpu.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -679,7 +679,6 @@ static int takedown_cpu(unsigned int cpu
 
 	/* Park the smpboot threads */
 	kthread_park(per_cpu_ptr(&cpuhp_state, cpu)->thread);
-	smpboot_park_threads(cpu);
 
 	/*
 	 * Prevent irq alloc/free while the dying cpu reorganizes the
@@ -1228,7 +1227,7 @@ static struct cpuhp_step cpuhp_ap_states
 	[CPUHP_AP_SMPBOOT_THREADS] = {
 		.name			= "smpboot/threads:online",
 		.startup.single		= smpboot_unpark_threads,
-		.teardown.single	= NULL,
+		.teardown.single	= smpboot_park_threads,
 	},
 	[CPUHP_AP_PERF_ONLINE] = {
 		.name			= "perf:online",