X-Git-Url: https://git.karo-electronics.de/?a=blobdiff_plain;f=kernel%2Frcutree_plugin.h;h=170814dc418f63a4753b1cfdae39d4d2dbff78cf;hb=e0fd9affeb64088eff407dfc98bbd3a5c17ea479;hp=d084ae3f281c2cad8a44075be8d3ebacadd7929c;hpb=5d434fcb255dec99189f1c58a06e4f56e12bf77d;p=karo-tx-linux.git

diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h
index d084ae3f281c..170814dc418f 100644
--- a/kernel/rcutree_plugin.h
+++ b/kernel/rcutree_plugin.h
@@ -28,6 +28,7 @@
 #include <linux/gfp.h>
 #include <linux/oom.h>
 #include <linux/smpboot.h>
+#include <linux/tick.h>
 
 #define RCU_KTHREAD_PRIO 1
 
@@ -1705,7 +1706,7 @@ static void rcu_prepare_for_idle(int cpu)
 		return;
 
 	/* If this is a no-CBs CPU, no callbacks, just return. */
-	if (is_nocb_cpu(cpu))
+	if (rcu_is_nocb_cpu(cpu))
 		return;
 
 	/*
@@ -1747,7 +1748,7 @@ static void rcu_cleanup_after_idle(int cpu)
 	struct rcu_data *rdp;
 	struct rcu_state *rsp;
 
-	if (is_nocb_cpu(cpu))
+	if (rcu_is_nocb_cpu(cpu))
 		return;
 	rcu_try_advance_all_cbs();
 	for_each_rcu_flavor(rsp) {
@@ -2052,7 +2053,7 @@ static void rcu_init_one_nocb(struct rcu_node *rnp)
 }
 
 /* Is the specified CPU a no-CPUs CPU? */
-static bool is_nocb_cpu(int cpu)
+bool rcu_is_nocb_cpu(int cpu)
 {
 	if (have_rcu_nocb_mask)
 		return cpumask_test_cpu(cpu, rcu_nocb_mask);
@@ -2110,7 +2111,7 @@ static bool __call_rcu_nocb(struct rcu_data *rdp, struct rcu_head *rhp,
 			    bool lazy)
 {
 
-	if (!is_nocb_cpu(rdp->cpu))
+	if (!rcu_is_nocb_cpu(rdp->cpu))
 		return 0;
 	__call_rcu_nocb_enqueue(rdp, rhp, &rhp->next, 1, lazy);
 	if (__is_kfree_rcu_offset((unsigned long)rhp->func))
@@ -2134,7 +2135,7 @@ static bool __maybe_unused rcu_nocb_adopt_orphan_cbs(struct rcu_state *rsp,
 	long qll = rsp->qlen_lazy;
 
 	/* If this is not a no-CBs CPU, tell the caller to do it the old way. */
-	if (!is_nocb_cpu(smp_processor_id()))
+	if (!rcu_is_nocb_cpu(smp_processor_id()))
 		return 0;
 	rsp->qlen = 0;
 	rsp->qlen_lazy = 0;
@@ -2306,11 +2307,6 @@ static void rcu_init_one_nocb(struct rcu_node *rnp)
 {
 }
 
-static bool is_nocb_cpu(int cpu)
-{
-	return false;
-}
-
 static bool __call_rcu_nocb(struct rcu_data *rdp, struct rcu_head *rhp,
 			    bool lazy)
 {
@@ -2337,3 +2333,20 @@ static bool init_nocb_callback_list(struct rcu_data *rdp)
 }
 
 #endif /* #else #ifdef CONFIG_RCU_NOCB_CPU */
+
+/*
+ * An adaptive-ticks CPU can potentially execute in kernel mode for an
+ * arbitrarily long period of time with the scheduling-clock tick turned
+ * off.  RCU will be paying attention to this CPU because it is in the
+ * kernel, but the CPU cannot be guaranteed to be executing the RCU state
+ * machine because the scheduling-clock tick has been disabled.  Therefore,
+ * if an adaptive-ticks CPU is failing to respond to the current grace
+ * period and has not be idle from an RCU perspective, kick it.
+ */
+static void rcu_kick_nohz_cpu(int cpu)
+{
+#ifdef CONFIG_NO_HZ_FULL
+	if (tick_nohz_full_cpu(cpu))
+		smp_send_reschedule(cpu);
+#endif /* #ifdef CONFIG_NO_HZ_FULL */
+}