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-rw-r--r--arch/um/drivers/mconsole_kern.c1
-rw-r--r--include/linux/rcupdate.h2
-rw-r--r--include/linux/sched.h8
-rw-r--r--kernel/rcutree.c15
-rw-r--r--kernel/sched/core.c1
5 files changed, 27 insertions, 0 deletions
diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c
index 664a60e8dfb..c17de0db673 100644
--- a/arch/um/drivers/mconsole_kern.c
+++ b/arch/um/drivers/mconsole_kern.c
@@ -705,6 +705,7 @@ static void stack_proc(void *arg)
struct task_struct *from = current, *to = arg;
to->thread.saved_task = from;
+ rcu_switch(from, to);
switch_to(from, to, from);
}
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index f5034f22e94..7c968e4f929 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -197,6 +197,8 @@ extern void rcu_user_enter(void);
extern void rcu_user_exit(void);
extern void rcu_user_enter_after_irq(void);
extern void rcu_user_exit_after_irq(void);
+extern void rcu_user_hooks_switch(struct task_struct *prev,
+ struct task_struct *next);
#else
static inline void rcu_user_enter(void) { }
static inline void rcu_user_exit(void) { }
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 23bddac4bad..335720a1fc3 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1885,6 +1885,14 @@ static inline void rcu_copy_process(struct task_struct *p)
#endif
+static inline void rcu_switch(struct task_struct *prev,
+ struct task_struct *next)
+{
+#ifdef CONFIG_RCU_USER_QS
+ rcu_user_hooks_switch(prev, next);
+#endif
+}
+
static inline void tsk_restore_flags(struct task_struct *task,
unsigned long orig_flags, unsigned long flags)
{
diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index 6b82a956514..d2e74c8d4b0 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -717,6 +717,21 @@ int rcu_is_cpu_idle(void)
}
EXPORT_SYMBOL(rcu_is_cpu_idle);
+#ifdef CONFIG_RCU_USER_QS
+void rcu_user_hooks_switch(struct task_struct *prev,
+ struct task_struct *next)
+{
+ struct rcu_dynticks *rdtp;
+
+ /* Interrupts are disabled in context switch */
+ rdtp = &__get_cpu_var(rcu_dynticks);
+ if (!rdtp->ignore_user_qs) {
+ clear_tsk_thread_flag(prev, TIF_NOHZ);
+ set_tsk_thread_flag(next, TIF_NOHZ);
+ }
+}
+#endif /* #ifdef CONFIG_RCU_USER_QS */
+
#if defined(CONFIG_PROVE_RCU) && defined(CONFIG_HOTPLUG_CPU)
/*
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 1a48cdbc863..ea2213b07d9 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2081,6 +2081,7 @@ context_switch(struct rq *rq, struct task_struct *prev,
#endif
/* Here we just switch the register state and the stack. */
+ rcu_switch(prev, next);
switch_to(prev, next, prev);
barrier();