---

yaml --- r: 323587 b: refs/heads/master c: c5d900b h: refs/heads/master i: 323585: bd67cee 323583: 375e9e5 v: v3
git-mirror · Sep 26, 2012 · 8ecf60d · 8ecf60d
1 parent c46953b
commit 8ecf60d
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Showing 3 changed files with 37 additions and 9 deletions.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 2b1d5024e17be459aa6385763ca3faa8f01c52d9
+refs/heads/master: c5d900bf676b1e2a61c44483932c8088651bbb4e
diff --git a/trunk/kernel/rcutree.c b/trunk/kernel/rcutree.c
@@ -366,11 +366,9 @@ static void rcu_eqs_enter_common(struct rcu_dynticks *rdtp, long long oldval,
  */
 static void rcu_eqs_enter(bool user)
 {
-	unsigned long flags;
 	long long oldval;
 	struct rcu_dynticks *rdtp;
 
-	local_irq_save(flags);
 	rdtp = &__get_cpu_var(rcu_dynticks);
 	oldval = rdtp->dynticks_nesting;
 	WARN_ON_ONCE((oldval & DYNTICK_TASK_NEST_MASK) == 0);
@@ -379,7 +377,6 @@ static void rcu_eqs_enter(bool user)
 	else
 		rdtp->dynticks_nesting -= DYNTICK_TASK_NEST_VALUE;
 	rcu_eqs_enter_common(rdtp, oldval, user);
-	local_irq_restore(flags);
 }
 
 /**
@@ -396,7 +393,11 @@ static void rcu_eqs_enter(bool user)
  */
 void rcu_idle_enter(void)
 {
+	unsigned long flags;
+
+	local_irq_save(flags);
 	rcu_eqs_enter(0);
+	local_irq_restore(flags);
 }
 EXPORT_SYMBOL_GPL(rcu_idle_enter);
 
@@ -411,6 +412,9 @@ EXPORT_SYMBOL_GPL(rcu_idle_enter);
  */
 void rcu_user_enter(void)
 {
+	unsigned long flags;
+	struct rcu_dynticks *rdtp;
+
 	/*
 	 * Some contexts may involve an exception occuring in an irq,
 	 * leading to that nesting:
@@ -422,7 +426,15 @@ void rcu_user_enter(void)
 	if (in_interrupt())
 		return;
 
-	rcu_eqs_enter(1);
+	WARN_ON_ONCE(!current->mm);
+
+	local_irq_save(flags);
+	rdtp = &__get_cpu_var(rcu_dynticks);
+	if (!rdtp->in_user) {
+		rdtp->in_user = true;
+		rcu_eqs_enter(1);
+	}
+	local_irq_restore(flags);
 }
 
 /**
@@ -516,11 +528,9 @@ static void rcu_eqs_exit_common(struct rcu_dynticks *rdtp, long long oldval,
  */
 static void rcu_eqs_exit(bool user)
 {
-	unsigned long flags;
 	struct rcu_dynticks *rdtp;
 	long long oldval;
 
-	local_irq_save(flags);
 	rdtp = &__get_cpu_var(rcu_dynticks);
 	oldval = rdtp->dynticks_nesting;
 	WARN_ON_ONCE(oldval < 0);
@@ -529,7 +539,6 @@ static void rcu_eqs_exit(bool user)
 	else
 		rdtp->dynticks_nesting = DYNTICK_TASK_EXIT_IDLE;
 	rcu_eqs_exit_common(rdtp, oldval, user);
-	local_irq_restore(flags);
 }
 
 /**
@@ -545,7 +554,11 @@ static void rcu_eqs_exit(bool user)
  */
 void rcu_idle_exit(void)
 {
+	unsigned long flags;
+
+	local_irq_save(flags);
 	rcu_eqs_exit(0);
+	local_irq_restore(flags);
 }
 EXPORT_SYMBOL_GPL(rcu_idle_exit);
 
@@ -558,6 +571,9 @@ EXPORT_SYMBOL_GPL(rcu_idle_exit);
  */
 void rcu_user_exit(void)
 {
+	unsigned long flags;
+	struct rcu_dynticks *rdtp;
+
 	/*
 	 * Some contexts may involve an exception occuring in an irq,
 	 * leading to that nesting:
@@ -569,7 +585,13 @@ void rcu_user_exit(void)
 	if (in_interrupt())
 		return;
 
-	rcu_eqs_exit(1);
+	local_irq_save(flags);
+	rdtp = &__get_cpu_var(rcu_dynticks);
+	if (rdtp->in_user) {
+		rdtp->in_user = false;
+		rcu_eqs_exit(1);
+	}
+	local_irq_restore(flags);
 }
 
 /**
@@ -2586,6 +2608,9 @@ rcu_boot_init_percpu_data(int cpu, struct rcu_state *rsp)
 	rdp->dynticks = &per_cpu(rcu_dynticks, cpu);
 	WARN_ON_ONCE(rdp->dynticks->dynticks_nesting != DYNTICK_TASK_EXIT_IDLE);
 	WARN_ON_ONCE(atomic_read(&rdp->dynticks->dynticks) != 1);
+#ifdef CONFIG_RCU_USER_QS
+	WARN_ON_ONCE(rdp->dynticks->in_user);
+#endif
 	rdp->cpu = cpu;
 	rdp->rsp = rsp;
 	raw_spin_unlock_irqrestore(&rnp->lock, flags);

diff --git a/trunk/kernel/rcutree.h b/trunk/kernel/rcutree.h
@@ -102,6 +102,9 @@ struct rcu_dynticks {
 				    /* idle-period nonlazy_posted snapshot. */
 	int tick_nohz_enabled_snap; /* Previously seen value from sysfs. */
 #endif /* #ifdef CONFIG_RCU_FAST_NO_HZ */
+#ifdef CONFIG_RCU_USER_QS
+	bool in_user;		    /* Is the CPU in userland from RCU POV? */
+#endif
 };
 
 /* RCU's kthread states for tracing. */