Re: [PATCH 1/7] rcu: fix incorrect conditional compilation

From: Paul E. McKenney
Date: Tue Oct 15 2019 - 23:35:26 EST


On Tue, Oct 15, 2019 at 10:23:56AM +0000, Lai Jiangshan wrote:
> DO NOT pick it to stable tree.
> (Since the title has "fix", this statement may help stop
> AI pick it to stable tree)
>
> The tokens SRCU and TINY_RCU are not defined by any configurations,
> they should be CONFIG_SRCU and CONFIG_TINY_RCU. But there is no
> harm when "TINY_RCU" is wrongly used, which are always non-defined,
> which makes "!defined(TINY_RCU)" always true, which means
> the code block is always inclued, and the included code block
> doesn't cause any compilation error so far when CONFIG_TINY_RCU.
> It is also the reason this change doesn't need for stable.
>
> Signed-off-by: Lai Jiangshan <jiangshanlai@xxxxxxxxx>
> Signed-off-by: Lai Jiangshan <laijs@xxxxxxxxxxxxxxxxx>

Applied for review and testing, thank you!

Thanx, Paul

> ---
> kernel/rcu/rcu.h | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h
> index a7ab2a023dd3..05f936ed167a 100644
> --- a/kernel/rcu/rcu.h
> +++ b/kernel/rcu/rcu.h
> @@ -254,7 +254,7 @@ void rcu_test_sync_prims(void);
> */
> extern void resched_cpu(int cpu);
>
> -#if defined(SRCU) || !defined(TINY_RCU)
> +#if defined(CONFIG_SRCU) || !defined(CONFIG_TINY_RCU)
>
> #include <linux/rcu_node_tree.h>
>
> @@ -391,7 +391,7 @@ do { \
> #define raw_lockdep_assert_held_rcu_node(p) \
> lockdep_assert_held(&ACCESS_PRIVATE(p, lock))
>
> -#endif /* #if defined(SRCU) || !defined(TINY_RCU) */
> +#endif /* #if defined(CONFIG_SRCU) || !defined(CONFIG_TINY_RCU) */
>
> #ifdef CONFIG_SRCU
> void srcu_init(void);
> --
> 2.20.1
>