[PATCH 1/1] rcu/kvfree: Do not run a page work if a cache is disabled

From: Uladzislau Rezki (Sony)
Date: Tue Apr 11 2023 - 09:13:54 EST


By default the cache size is 5 pages per-cpu. But it can
be disabled at boot time by setting the rcu_min_cached_objs
to zero.

Signed-off-by: Uladzislau Rezki (Sony) <urezki@xxxxxxxxx>
---
kernel/rcu/tree.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 35be35f8236b..21e3d9dffde5 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -3246,6 +3246,10 @@ static void fill_page_cache_func(struct work_struct *work)
static void
run_page_cache_worker(struct kfree_rcu_cpu *krcp)
{
+ // If cache disabled, bail out.
+ if (!rcu_min_cached_objs)
+ return;
+
if (rcu_scheduler_active == RCU_SCHEDULER_RUNNING &&
!atomic_xchg(&krcp->work_in_progress, 1)) {
if (atomic_read(&krcp->backoff_page_cache_fill)) {
--
2.30.2