2 files changed, 37 insertions, 12 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index e6473ecaab3c..c962922784d1 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1728,8 +1728,6 @@ void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags)
 
 #ifdef CONFIG_SMP
 
-#ifdef CONFIG_PREEMPT_RT
-
 static void
 __do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask, u32 flags);
 
@@ -1800,8 +1798,6 @@ static inline bool rq_has_pinned_tasks(struct rq *rq)
 	return rq->nr_pinned;
 }
 
-#endif
-
 /*
  * Per-CPU kthreads are allowed to run on !active && online CPUs, see
  * __set_cpus_allowed_ptr() and select_fallback_rq().
@@ -2882,7 +2878,7 @@ void sched_set_stop_task(int cpu, struct task_struct *stop)
 	}
 }
 
-#else
+#else /* CONFIG_SMP */
 
 static inline int __set_cpus_allowed_ptr(struct task_struct *p,
 					 const struct cpumask *new_mask,
@@ -2891,10 +2887,6 @@ static inline int __set_cpus_allowed_ptr(struct task_struct *p,
 	return set_cpus_allowed_ptr(p, new_mask);
 }
 
-#endif /* CONFIG_SMP */
-
-#if !defined(CONFIG_SMP) || !defined(CONFIG_PREEMPT_RT)
-
 static inline void migrate_disable_switch(struct rq *rq, struct task_struct *p) { }
 
 static inline bool rq_has_pinned_tasks(struct rq *rq)
@@ -2902,7 +2894,7 @@ static inline bool rq_has_pinned_tasks(struct rq *rq)
 	return false;
 }
 
-#endif
+#endif /* !CONFIG_SMP */
 
 static void
 ttwu_stat(struct task_struct *p, int cpu, int wake_flags)
@@ -7924,6 +7916,39 @@ void __cant_sleep(const char *file, int line, int preempt_offset)
 	add_taint(TAINT_WARN, LOCKDEP_STILL_OK);
 }
 EXPORT_SYMBOL_GPL(__cant_sleep);
+
+#ifdef CONFIG_SMP
+void __cant_migrate(const char *file, int line)
+{
+	static unsigned long prev_jiffy;
+
+	if (irqs_disabled())
+		return;
+
+	if (is_migration_disabled(current))
+		return;
+
+	if (!IS_ENABLED(CONFIG_PREEMPT_COUNT))
+		return;
+
+	if (preempt_count() > 0)
+		return;
+
+	if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy)
+		return;
+	prev_jiffy = jiffies;
+
+	pr_err("BUG: assuming non migratable context at %s:%d\n", file, line);
+	pr_err("in_atomic(): %d, irqs_disabled(): %d, migration_disabled() %u pid: %d, name: %s\n",
+	       in_atomic(), irqs_disabled(), is_migration_disabled(current),
+	       current->pid, current->comm);
+
+	debug_show_held_locks(current);
+	dump_stack();
+	add_taint(TAINT_WARN, LOCKDEP_STILL_OK);
+}
+EXPORT_SYMBOL_GPL(__cant_migrate);
+#endif
 #endif
 
 #ifdef CONFIG_MAGIC_SYSRQ
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 590e6f27068c..f5acb6c5ce49 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -1056,7 +1056,7 @@ struct rq {
 	struct cpuidle_state	*idle_state;
 #endif
 
-#if defined(CONFIG_PREEMPT_RT) && defined(CONFIG_SMP)
+#ifdef CONFIG_SMP
 	unsigned int		nr_pinned;
 #endif
 	unsigned int		push_busy;
@@ -1092,7 +1092,7 @@ static inline int cpu_of(struct rq *rq)
 
 static inline bool is_migration_disabled(struct task_struct *p)
 {
-#if defined(CONFIG_SMP) && defined(CONFIG_PREEMPT_RT)
+#ifdef CONFIG_SMP
 	return p->migration_disabled;
 #else
 	return false;