If the rcu_min_cached_objs is set to zero at boot params, the krcp->page_cache_work will not be triggered to fill page cache, and the put_cached_bnode() also does not fill page cache, this also means the krcp->bkvcache is always empty, so not need to acquire unnecessary krcp->lock to get page from krcp->bkvcache, this commit therefore make drain_page_cache() return directly if the rcu_min_cached_objs is zero. Signed-off-by: Zqiang <qiang1.zhang@xxxxxxxxx> --- kernel/rcu/tree.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 93faf9f5c58f..00620a2117de 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -2924,6 +2924,9 @@ drain_page_cache(struct kfree_rcu_cpu *krcp) struct llist_node *page_list, *pos, *n; int freed = 0; + if (!rcu_min_cached_objs) + return 0; + raw_spin_lock_irqsave(&krcp->lock, flags); page_list = llist_del_all(&krcp->bkvcache); WRITE_ONCE(krcp->nr_bkv_objs, 0); -- 2.32.0
