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

Boqun Feng
2025-04-14T06:01:25Z

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

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
---
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