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-rw-r--r--include/linux/rcutiny.h4
-rw-r--r--include/linux/rcutree.h1
-rw-r--r--kernel/rcutree.c20
-rw-r--r--kernel/rcutree.h1
-rw-r--r--kernel/rcutree_plugin.h18
5 files changed, 44 insertions, 0 deletions
diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h
index 4cc5eba..3fa1797 100644
--- a/include/linux/rcutiny.h
+++ b/include/linux/rcutiny.h
@@ -178,6 +178,10 @@ static inline void rcu_sched_force_quiescent_state(void)
{
}
+static inline void rcu_cpu_stall_reset(void)
+{
+}
+
#ifdef CONFIG_DEBUG_LOCK_ALLOC
extern int rcu_scheduler_active __read_mostly;
diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h
index c13b85d..0726809 100644
--- a/include/linux/rcutree.h
+++ b/include/linux/rcutree.h
@@ -36,6 +36,7 @@ extern void rcu_sched_qs(int cpu);
extern void rcu_bh_qs(int cpu);
extern void rcu_note_context_switch(int cpu);
extern int rcu_needs_cpu(int cpu);
+extern void rcu_cpu_stall_reset(void);
#ifdef CONFIG_TREE_PREEMPT_RCU
diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index ff21411..42140a8 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -565,6 +565,22 @@ static int rcu_panic(struct notifier_block *this, unsigned long ev, void *ptr)
return NOTIFY_DONE;
}
+/**
+ * rcu_cpu_stall_reset - prevent further stall warnings in current grace period
+ *
+ * Set the stall-warning timeout way off into the future, thus preventing
+ * any RCU CPU stall-warning messages from appearing in the current set of
+ * RCU grace periods.
+ *
+ * The caller must disable hard irqs.
+ */
+void rcu_cpu_stall_reset(void)
+{
+ rcu_sched_state.jiffies_stall = jiffies + ULONG_MAX / 2;
+ rcu_bh_state.jiffies_stall = jiffies + ULONG_MAX / 2;
+ rcu_preempt_stall_reset();
+}
+
static struct notifier_block rcu_panic_block = {
.notifier_call = rcu_panic,
};
@@ -584,6 +600,10 @@ static void check_cpu_stall(struct rcu_state *rsp, struct rcu_data *rdp)
{
}
+void rcu_cpu_stall_reset(void)
+{
+}
+
static void __init check_cpu_stall_init(void)
{
}
diff --git a/kernel/rcutree.h b/kernel/rcutree.h
index bb4d086..7abd439 100644
--- a/kernel/rcutree.h
+++ b/kernel/rcutree.h
@@ -372,6 +372,7 @@ static void rcu_report_unblock_qs_rnp(struct rcu_node *rnp,
#ifdef CONFIG_RCU_CPU_STALL_DETECTOR
static void rcu_print_detail_task_stall(struct rcu_state *rsp);
static void rcu_print_task_stall(struct rcu_node *rnp);
+static void rcu_preempt_stall_reset(void);
#endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */
static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp);
#ifdef CONFIG_HOTPLUG_CPU
diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h
index 63bb771..561410f 100644
--- a/kernel/rcutree_plugin.h
+++ b/kernel/rcutree_plugin.h
@@ -417,6 +417,16 @@ static void rcu_print_task_stall(struct rcu_node *rnp)
}
}
+/*
+ * Suppress preemptible RCU's CPU stall warnings by pushing the
+ * time of the next stall-warning message comfortably far into the
+ * future.
+ */
+static void rcu_preempt_stall_reset(void)
+{
+ rcu_preempt_state.jiffies_stall = jiffies + ULONG_MAX / 2;
+}
+
#endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */
/*
@@ -867,6 +877,14 @@ static void rcu_print_task_stall(struct rcu_node *rnp)
{
}
+/*
+ * Because preemptible RCU does not exist, there is no need to suppress
+ * its CPU stall warnings.
+ */
+static void rcu_preempt_stall_reset(void)
+{
+}
+
#endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */
/*
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