[RFC PATCH 2/8] shazptr: Add refscale test

[Boqun Feng]

Add the refscale test for shazptr to measure the reader side
performance.

Signed-off-by: Boqun Feng <boqun.feng@xxxxxxxxx>
---
 kernel/rcu/refscale.c | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/kernel/rcu/refscale.c b/kernel/rcu/refscale.c
index f11a7c2af778..154520e4ee4c 100644
--- a/kernel/rcu/refscale.c
+++ b/kernel/rcu/refscale.c
@@ -29,6 +29,7 @@
 #include <linux/reboot.h>
 #include <linux/sched.h>
 #include <linux/seq_buf.h>
+#include <linux/shazptr.h>
 #include <linux/spinlock.h>
 #include <linux/smp.h>
 #include <linux/stat.h>
@@ -890,6 +891,43 @@ static const struct ref_scale_ops typesafe_seqlock_ops = {
 	.name		= "typesafe_seqlock"
 };
 
+static void ref_shazptr_read_section(const int nloops)
+{
+	int i;
+
+	for (i = nloops; i >= 0; i--) {
+		preempt_disable();
+		{ guard(shazptr)(ref_shazptr_read_section); }
+		preempt_enable();
+	}
+}
+
+static void ref_shazptr_delay_section(const int nloops, const int udl, const int ndl)
+{
+	int i;
+
+	for (i = nloops; i >= 0; i--) {
+		preempt_disable();
+		{
+			guard(shazptr)(ref_shazptr_delay_section);
+			un_delay(udl, ndl);
+		}
+		preempt_enable();
+	}
+}
+
+static bool ref_shazptr_init(void)
+{
+	return true;
+}
+
+static const struct ref_scale_ops shazptr_ops = {
+	.init		= ref_shazptr_init,
+	.readsection	= ref_shazptr_read_section,
+	.delaysection	= ref_shazptr_delay_section,
+	.name		= "shazptr"
+};
+
 static void rcu_scale_one_reader(void)
 {
 	if (readdelay <= 0)
@@ -1197,6 +1235,7 @@ ref_scale_init(void)
 		&refcnt_ops, &rwlock_ops, &rwsem_ops, &lock_ops, &lock_irq_ops,
 		&acqrel_ops, &sched_clock_ops, &clock_ops, &jiffies_ops,
 		&typesafe_ref_ops, &typesafe_lock_ops, &typesafe_seqlock_ops,
+		&shazptr_ops,
 	};
 
 	if (!torture_init_begin(scale_type, verbose))
-- 
2.47.1