Re: [PATCH v3] rcu: Make call_rcu() lazy only when CONFIG_RCU_LAZY is enabled

From: Joel Fernandes
Date: Thu Oct 20 2022 - 04:28:07 EST



> On Oct 19, 2022, at 8:56 PM, Zqiang <qiang1.zhang@xxxxxxxxx> wrote:
>
> 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->v3:
> Use IS_ENABLED(CONFIG_RCU_LAZY) to the existing function of the same name.

Acked-by: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx>

Best,

- J


> kernel/rcu/tree.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
> index abc615808b6e..1f6a4b2b13da 100644
> --- a/kernel/rcu/tree.c
> +++ b/kernel/rcu/tree.c
> @@ -2887,7 +2887,7 @@ EXPORT_SYMBOL_GPL(call_rcu_flush);
> */
> void call_rcu(struct rcu_head *head, rcu_callback_t func)
> {
> - return __call_rcu_common(head, func, true);
> + return __call_rcu_common(head, func, IS_ENABLED(CONFIG_RCU_LAZY));
> }
> EXPORT_SYMBOL_GPL(call_rcu);
>
> --
> 2.25.1
>