linux/debian/patches-rt/0312-sched-core-migrate_ena...

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1.9 KiB
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From 542037f313bfa2842d2733780cb6c9d57f451ddf Mon Sep 17 00:00:00 2001
Message-Id: <542037f313bfa2842d2733780cb6c9d57f451ddf.1601675153.git.zanussi@kernel.org>
In-Reply-To: <5b5a156f9808b1acf1205606e03da117214549ea.1601675151.git.zanussi@kernel.org>
References: <5b5a156f9808b1acf1205606e03da117214549ea.1601675151.git.zanussi@kernel.org>
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Fri, 29 Nov 2019 17:24:55 +0100
Subject: [PATCH 312/333] sched/core: migrate_enable() must access
takedown_cpu_task on !HOTPLUG_CPU
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.148-rt64.tar.xz
[ 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 --git a/kernel/cpu.c b/kernel/cpu.c
index bf698d84ac2a..0651576f9974 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -861,7 +861,9 @@ 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 10c7412bb012..2509cb37531d 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -7309,9 +7309,11 @@ 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;
--
2.17.1