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-rw-r--r--kernel/rcu/tree.c18
1 files changed, 18 insertions, 0 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 5e98257c2910..4ac019e9b25f 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -1076,6 +1076,24 @@ void rcu_irq_enter_irqson(void)
}
/*
+ * Check to see if any future non-offloaded RCU-related work will need
+ * to be done by the current CPU, even if none need be done immediately,
+ * returning 1 if so. This function is part of the RCU implementation;
+ * it is -not- an exported member of the RCU API. This is used by
+ * the idle-entry code to figure out whether it is safe to disable the
+ * scheduler-clock interrupt.
+ *
+ * Just check whether or not this CPU has non-offloaded RCU callbacks
+ * queued.
+ */
+int rcu_needs_cpu(u64 basemono, u64 *nextevt)
+{
+ *nextevt = KTIME_MAX;
+ return !rcu_segcblist_empty(&this_cpu_ptr(&rcu_data)->cblist) &&
+ !rcu_rdp_is_offloaded(this_cpu_ptr(&rcu_data));
+}
+
+/*
* If any sort of urgency was applied to the current CPU (for example,
* the scheduler-clock interrupt was enabled on a nohz_full CPU) in order
* to get to a quiescent state, disable it.