Re: [PATCH printk v3 01/40] rcu: implement lockdep_rcu_enabled for !CONFIG_DEBUG_LOCK_ALLOC

From: Petr Mladek
Date: Tue Nov 08 2022 - 05:29:40 EST


On Mon 2022-11-07 15:21:59, John Ogness wrote:
> Provide an implementation for debug_lockdep_rcu_enabled() when
> CONFIG_DEBUG_LOCK_ALLOC is not enabled. This allows code to check
> if rcu lockdep debugging is available without needing an extra
> check if CONFIG_DEBUG_LOCK_ALLOC is enabled.
>
> Signed-off-by: John Ogness <john.ogness@xxxxxxxxxxxxx>

Reviewed-by: Petr Mladek <pmladek@xxxxxxxx>

Just a small nit below.

> ---
> I also sent this patch to Paul as a suggestion. If it is not
> acceptable, I just need to add an ifdef CONFIG_DEBUG_LOCK_ALLOC
> into console_list_lock() of patch 21.
>
> include/linux/rcupdate.h | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
> index 08605ce7379d..65178c40ab6f 100644
> --- a/include/linux/rcupdate.h
> +++ b/include/linux/rcupdate.h
> @@ -340,6 +340,11 @@ static inline int rcu_read_lock_any_held(void)
> return !preemptible();
> }
>
> +static inline int debug_lockdep_rcu_enabled(void)
> +{
> + return 0;
> +}
> +

It would make sense to move this up before rcu_read_lock_held()
definition so that the declarations and definitions are in
the same order in both #ifdef CONFIG_DEBUG_LOCK_ALLOC branches.

> #endif /* #else #ifdef CONFIG_DEBUG_LOCK_ALLOC */
>
> #ifdef CONFIG_PROVE_RCU

Best Regards,
PEtr