---

yaml
---
r: 323584
b: refs/heads/master
c: 19dd159
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: adf5091e6ccaa02905e7a28f9ff44f46c7f4c230
+refs/heads/master: 19dd1591fc379f1d89f39cd99cbbe97433baa3c3

trunk/include/linux/rcupdate.h

@@ -193,6 +193,8 @@ extern void rcu_irq_enter(void);
 extern void rcu_irq_exit(void);
 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 exit_rcu(void);
 
 /**

trunk/kernel/rcutree.c

@@ -425,6 +425,27 @@ void rcu_user_enter(void)
 }
 
 
+/**
+ * rcu_user_enter_after_irq - inform RCU that we are going to resume userspace
+ * after the current irq returns.
+ *
+ * This is similar to rcu_user_enter() but in the context of a non-nesting
+ * irq. After this call, RCU enters into idle mode when the interrupt
+ * returns.
+ */
+void rcu_user_enter_after_irq(void)
+{
+	unsigned long flags;
+	struct rcu_dynticks *rdtp;
+
+	local_irq_save(flags);
+	rdtp = &__get_cpu_var(rcu_dynticks);
+	/* Ensure this irq is interrupting a non-idle RCU state.  */
+	WARN_ON_ONCE(!(rdtp->dynticks_nesting & DYNTICK_TASK_MASK));
+	rdtp->dynticks_nesting = 1;
+	local_irq_restore(flags);
+}
+
 /**
  * rcu_irq_exit - inform RCU that current CPU is exiting irq towards idle
  *
@@ -549,6 +570,28 @@ void rcu_user_exit(void)
 	rcu_eqs_exit(1);
 }
 
+/**
+ * rcu_user_exit_after_irq - inform RCU that we won't resume to userspace
+ * idle mode after the current non-nesting irq returns.
+ *
+ * This is similar to rcu_user_exit() but in the context of an irq.
+ * This is called when the irq has interrupted a userspace RCU idle mode
+ * context. When the current non-nesting interrupt returns after this call,
+ * the CPU won't restore the RCU idle mode.
+ */
+void rcu_user_exit_after_irq(void)
+{
+	unsigned long flags;
+	struct rcu_dynticks *rdtp;
+
+	local_irq_save(flags);
+	rdtp = &__get_cpu_var(rcu_dynticks);
+	/* Ensure we are interrupting an RCU idle mode. */
+	WARN_ON_ONCE(rdtp->dynticks_nesting & DYNTICK_TASK_NEST_MASK);
+	rdtp->dynticks_nesting += DYNTICK_TASK_EXIT_IDLE;
+	local_irq_restore(flags);
+}
+
 /**
  * rcu_irq_enter - inform RCU that current CPU is entering irq away from idle
  *