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-rw-r--r--kernel/rcu/rcu.h36
1 files changed, 36 insertions, 0 deletions
diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h
index a943b42a9cf7..87326479b39a 100644
--- a/kernel/rcu/rcu.h
+++ b/kernel/rcu/rcu.h
@@ -190,4 +190,40 @@ void rcu_test_sync_prims(void);
*/
extern void resched_cpu(int cpu);
+#if defined(SRCU) || !defined(TINY_RCU)
+
+#include <linux/rcu_node_tree.h>
+
+extern int rcu_num_lvls;
+extern int rcu_num_nodes;
+static bool rcu_fanout_exact;
+static int rcu_fanout_leaf;
+
+/*
+ * Compute the per-level fanout, either using the exact fanout specified
+ * or balancing the tree, depending on the rcu_fanout_exact boot parameter.
+ */
+static inline void rcu_init_levelspread(int *levelspread, const int *levelcnt)
+{
+ int i;
+
+ if (rcu_fanout_exact) {
+ levelspread[rcu_num_lvls - 1] = rcu_fanout_leaf;
+ for (i = rcu_num_lvls - 2; i >= 0; i--)
+ levelspread[i] = RCU_FANOUT;
+ } else {
+ int ccur;
+ int cprv;
+
+ cprv = nr_cpu_ids;
+ for (i = rcu_num_lvls - 1; i >= 0; i--) {
+ ccur = levelcnt[i];
+ levelspread[i] = (cprv + ccur - 1) / ccur;
+ cprv = ccur;
+ }
+ }
+}
+
+#endif /* #if defined(SRCU) || !defined(TINY_RCU) */
+
#endif /* __LINUX_RCU_H */