This commit creates a new srcu-fast option for the refscale.scale_type
module parameter that selects srcu_read_lock_fast() and
srcu_read_unlock_fast().
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
Cc: Alexei Starovoitov <ast@xxxxxxxxxx>
Cc: Andrii Nakryiko <andrii@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Kent Overstreet <kent.overstreet@xxxxxxxxx>
Cc: <bpf@xxxxxxxxxxxxxxx>
---
kernel/rcu/refscale.c | 32 +++++++++++++++++++++++++++++++-
1 file changed, 31 insertions(+), 1 deletion(-)
diff --git a/kernel/rcu/refscale.c b/kernel/rcu/refscale.c
index 1b47376acdc40..f11a7c2af778c 100644
--- a/kernel/rcu/refscale.c
+++ b/kernel/rcu/refscale.c
@@ -216,6 +216,36 @@ static const struct ref_scale_ops srcu_ops = {
.name = "srcu"
};
+static void srcu_fast_ref_scale_read_section(const int nloops)
+{
+ int i;
+ struct srcu_ctr __percpu *scp;
+
+ for (i = nloops; i >= 0; i--) {
+ scp = srcu_read_lock_fast(srcu_ctlp);
+ srcu_read_unlock_fast(srcu_ctlp, scp);
+ }
+}
+
+static void srcu_fast_ref_scale_delay_section(const int nloops, const int udl, const int ndl)
+{
+ int i;
+ struct srcu_ctr __percpu *scp;
+
+ for (i = nloops; i >= 0; i--) {
+ scp = srcu_read_lock_fast(srcu_ctlp);
+ un_delay(udl, ndl);
+ srcu_read_unlock_fast(srcu_ctlp, scp);
+ }
+}
+
+static const struct ref_scale_ops srcu_fast_ops = {
+ .init = rcu_sync_scale_init,
+ .readsection = srcu_fast_ref_scale_read_section,
+ .delaysection = srcu_fast_ref_scale_delay_section,
+ .name = "srcu-fast"
+};
+
static void srcu_lite_ref_scale_read_section(const int nloops)
{
int i;
@@ -1163,7 +1193,7 @@ ref_scale_init(void)
long i;
int firsterr = 0;
static const struct ref_scale_ops *scale_ops[] = {
- &rcu_ops, &srcu_ops, &srcu_lite_ops, RCU_TRACE_OPS RCU_TASKS_OPS
+ &rcu_ops, &srcu_ops, &srcu_fast_ops, &srcu_lite_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,
&typesafe_ref_ops, &typesafe_lock_ops, &typesafe_seqlock_ops,
--
2.40.1
