[PATCH v2] rcu: Make call_rcu() lazy only when CONFIG_RCU_LAZY is enabled

From: Zqiang
Date: Wed Oct 19 2022 - 19:32:51 EST


Currently, regardless of whether the CONFIG_RCU_LAZY is enabled,
invoke the call_rcu() is always lazy, it also means that when
CONFIG_RCU_LAZY is disabled, invoke the call_rcu_flush() is also
lazy. therefore, this commit make call_rcu() lazy only when
CONFIG_RCU_LAZY is enabled.

Signed-off-by: Zqiang <qiang1.zhang@xxxxxxxxx>
---
v1->v2:
Use IS_ENABLED(CONFIG_RCU_LAZY) to the existing function of the same name.

kernel/rcu/tree.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index abc615808b6e..ecf42b0d3726 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -2887,7 +2887,10 @@ EXPORT_SYMBOL_GPL(call_rcu_flush);
*/
void call_rcu(struct rcu_head *head, rcu_callback_t func)
{
- return __call_rcu_common(head, func, true);
+ if (IS_ENABLED(CONFIG_RCU_LAZY))
+ return __call_rcu_common(head, func, true);
+ else
+ return __call_rcu_common(head, func, false);
}
EXPORT_SYMBOL_GPL(call_rcu);

--
2.25.1