[PATCH v4 18/48] rcu: dynamically allocate the rcu-lazy shrinker

From: Qi Zheng
Date: Mon Aug 07 2023 - 07:17:05 EST


Use new APIs to dynamically allocate the rcu-lazy shrinker.

Signed-off-by: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
---
kernel/rcu/tree_nocb.h | 20 +++++++++++---------
1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/kernel/rcu/tree_nocb.h b/kernel/rcu/tree_nocb.h
index 5598212d1f27..e1c59c33738a 100644
--- a/kernel/rcu/tree_nocb.h
+++ b/kernel/rcu/tree_nocb.h
@@ -1396,13 +1396,6 @@ lazy_rcu_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)

return count ? count : SHRINK_STOP;
}
-
-static struct shrinker lazy_rcu_shrinker = {
- .count_objects = lazy_rcu_shrink_count,
- .scan_objects = lazy_rcu_shrink_scan,
- .batch = 0,
- .seeks = DEFAULT_SEEKS,
-};
#endif // #ifdef CONFIG_RCU_LAZY

void __init rcu_init_nohz(void)
@@ -1410,6 +1403,7 @@ void __init rcu_init_nohz(void)
int cpu;
struct rcu_data *rdp;
const struct cpumask *cpumask = NULL;
+ struct shrinker * __maybe_unused lazy_rcu_shrinker;

#if defined(CONFIG_NO_HZ_FULL)
if (tick_nohz_full_running && !cpumask_empty(tick_nohz_full_mask))
@@ -1436,8 +1430,16 @@ void __init rcu_init_nohz(void)
return;

#ifdef CONFIG_RCU_LAZY
- if (register_shrinker(&lazy_rcu_shrinker, "rcu-lazy"))
- pr_err("Failed to register lazy_rcu shrinker!\n");
+ lazy_rcu_shrinker = shrinker_alloc(0, "rcu-lazy");
+ if (!lazy_rcu_shrinker) {
+ pr_err("Failed to allocate lazy_rcu shrinker!\n");
+ } else {
+ lazy_rcu_shrinker->count_objects = lazy_rcu_shrink_count;
+ lazy_rcu_shrinker->scan_objects = lazy_rcu_shrink_scan;
+ lazy_rcu_shrinker->seeks = DEFAULT_SEEKS;
+
+ shrinker_register(lazy_rcu_shrinker);
+ }
#endif // #ifdef CONFIG_RCU_LAZY

if (!cpumask_subset(rcu_nocb_mask, cpu_possible_mask)) {
--
2.30.2