commit 0c8e0e3c37955d17cced37222a10c00ab47efd4b
author Paul E. McKenney <paulmck@linux.vnet.ibm.com> Fri Apr 28 11:24:22 2017 -0700
committer Paul E. McKenney <paulmck@linux.vnet.ibm.com> Thu Jun 08 08:25:36 2017 -0700
tree 82b1a3ec2ffa39a38da69d52231a0b2e2560f87f
parent b5815e6cd3b747cacf7628a32a275aa2c0f61e06

srcu: Print non-default exp_holdoff values at boot time

This commit makes srcu_bootup_announce() check for non-default values
of the auto-expedite holdoff time exp_holdoff and print a message if so.

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

kernel/rcu/srcutree.c

diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c
index 08d4373..0b6ea10 100644
--- a/kernel/rcu/srcutree.c
+++ b/kernel/rcu/srcutree.c
@@ -40,7 +40,9 @@
 #include "rcu.h"
 #include "rcu_segcblist.h"
 
-static ulong exp_holdoff = 25 * 1000; /* Holdoff (ns) for auto-expediting. */
+/* Holdoff in nanoseconds for auto-expediting. */
+#define DEFAULT_SRCU_EXP_HOLDOFF (25 * 1000)
+static ulong exp_holdoff = DEFAULT_SRCU_EXP_HOLDOFF;
 module_param(exp_holdoff, ulong, 0444);
 
 static void srcu_invoke_callbacks(struct work_struct *work);
@@ -1171,6 +1173,8 @@ EXPORT_SYMBOL_GPL(srcutorture_get_gp_data);
 static int __init srcu_bootup_announce(void)
 {
 	pr_info("Hierarchical SRCU implementation.\n");
+	if (exp_holdoff != DEFAULT_SRCU_EXP_HOLDOFF)
+		pr_info("\tNon-default auto-expedite holdoff of %lu ns.\n", exp_holdoff);
 	return 0;
 }
 early_initcall(srcu_bootup_announce);