srcutorture: Print Tiny SRCU reader statistics

The srcu_torture_stats() function is adapted to the specific srcu_struct
layout traditionally used by SRCU.  This commit therefore adds support
for Tiny SRCU.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 98591e1..9cbb8a7 100644 (file)
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -559,11 +559,12 @@ static void srcu_torture_barrier(void)
 
 static void srcu_torture_stats(void)
 {
-#ifdef CONFIG_TREE_SRCU
-       int cpu;
-       int idx = srcu_ctlp->completed & 0x1;
+       int __maybe_unused cpu;
+       int idx;
 
-       pr_alert("%s%s per-CPU(idx=%d):",
+#ifdef CONFIG_TREE_SRCU
+       idx = srcu_ctlp->completed & 0x1;
+       pr_alert("%s%s Tree SRCU per-CPU(idx=%d):",
                 torture_type, TORTURE_FLAG, idx);
        for_each_possible_cpu(cpu) {
                unsigned long l0, l1;
@@ -588,6 +589,12 @@ static void srcu_torture_stats(void)
                pr_cont(" %d(%ld,%ld)", cpu, c0, c1);
        }
        pr_cont("\n");
+#elif defined(CONFIG_TINY_SRCU)
+       idx = READ_ONCE(srcu_ctlp->srcu_idx) & 0x1;
+       pr_alert("%s%s Tiny SRCU per-CPU(idx=%d): (%d,%d)\n",
+                torture_type, TORTURE_FLAG, idx,
+                READ_ONCE(srcu_ctlp->srcu_lock_nesting[!idx]),
+                READ_ONCE(srcu_ctlp->srcu_lock_nesting[idx]));
 #endif
 }