This commit adds refscale readers based on local_bh_disable() and
local_bh_enable() ("refscale.scale_type=bh"). On my x86 laptop, these
are about 4.9ns.
Signed-off-by: Paul E. McKenney <[email protected]>
---
kernel/rcu/refscale.c | 34 +++++++++++++++++++++++++++++++++-
1 file changed, 33 insertions(+), 1 deletion(-)
diff --git a/kernel/rcu/refscale.c b/kernel/rcu/refscale.c
index 266a3fa94b54..1faed90231ab 100644
--- a/kernel/rcu/refscale.c
+++ b/kernel/rcu/refscale.c
@@ -636,6 +636,37 @@ static const struct ref_scale_ops jiffies_ops = {
.name = "jiffies"
};
+static void ref_bh_section(const int nloops)
+{
+ int i;
+
+ preempt_disable();
+ for (i = nloops; i >= 0; i--) {
+ local_bh_disable();
+ local_bh_enable();
+ }
+ preempt_enable();
+}
+
+static void ref_bh_delay_section(const int nloops, const int udl, const int
ndl)
+{
+ int i;
+
+ preempt_disable();
+ for (i = nloops; i >= 0; i--) {
+ local_bh_disable();
+ un_delay(udl, ndl);
+ local_bh_enable();
+ }
+ preempt_enable();
+}
+
+static const struct ref_scale_ops bh_ops = {
+ .readsection = ref_bh_section,
+ .delaysection = ref_bh_delay_section,
+ .name = "bh"
+};
+
static void ref_irq_section(const int nloops)
{
int i;
@@ -1236,7 +1267,8 @@ ref_scale_init(void)
static const struct ref_scale_ops *scale_ops[] = {
&rcu_ops, &srcu_ops, &srcu_fast_ops, RCU_TRACE_OPS RCU_TASKS_OPS
&refcnt_ops, &rwlock_ops, &rwsem_ops, &lock_ops, &lock_irq_ops,
- &acqrel_ops, &sched_clock_ops, &clock_ops, &jiffies_ops,
&irq_ops, &irqsave_ops,
+ &acqrel_ops, &sched_clock_ops, &clock_ops, &jiffies_ops,
+ &bh_ops, &irq_ops, &irqsave_ops,
&typesafe_ref_ops, &typesafe_lock_ops, &typesafe_seqlock_ops,
};
--
2.40.1
