diff mbox series

[RT,27/30] sched/core: migrate_enable() must access takedown_cpu_task on !HOTPLUG_CPU

Message ID 20200123203946.200669575@goodmis.org
State New
Headers show
Series None | expand

Commit Message

Steven Rostedt Jan. 23, 2020, 8:39 p.m. UTC 
4.19.94-rt39-rc2 stable review patch.
If anyone has any objections, please let me know.

------------------

From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

[ Upstream commit a61d1977f692e46bad99a100f264981ba08cb4bd ]

The variable takedown_cpu_task is never declared/used on !HOTPLUG_CPU
except for migrate_enable(). This leads to a link error.

Don't use takedown_cpu_task in !HOTPLUG_CPU.

Reported-by: Dick Hollenbeck <dick@softplc.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 kernel/cpu.c        | 2 ++
 kernel/sched/core.c | 2 ++
 2 files changed, 4 insertions(+)
diff mbox series

Patch

diff --git a/kernel/cpu.c b/kernel/cpu.c
index 5366c8c69c2f..b9d7ac61d707 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -846,7 +846,9 @@  static int take_cpu_down(void *_param)
 	return 0;
 }
 
+#ifdef CONFIG_PREEMPT_RT_BASE
 struct task_struct *takedown_cpu_task;
+#endif
 
 static int takedown_cpu(unsigned int cpu)
 {
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index e465381b464d..cbd76324babd 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -7314,9 +7314,11 @@  void migrate_enable(void)
 
 	p->migrate_disable = 0;
 	rq->nr_pinned--;
+#ifdef CONFIG_HOTPLUG_CPU
 	if (rq->nr_pinned == 0 && unlikely(!cpu_active(cpu)) &&
 	    takedown_cpu_task)
 		wake_up_process(takedown_cpu_task);
+#endif
 
 	if (!p->migrate_disable_scheduled)
 		goto out;