Re: [PATCH V1] rcu-tasks: Fix build error

[Greg KH <gregkh@linuxfoundation.org>]

On Mon, Feb 20, 2023 at 11:43:59PM +0530, Srinivasarao Pathipati wrote:
> Making show_rcu_tasks_rude_gp_kthread() function as 'inline' to
> fix below compilation error.
> This is applicable to only 5.10 kernels as code got modified
> in latest kernels.
> 
>  In file included from kernel/rcu/update.c:579:0:
>  kernel/rcu/tasks.h:710:13: error: ‘show_rcu_tasks_rude_gp_kthread’ defined but not used [-Werror=unused-function]
>   static void show_rcu_tasks_rude_gp_kthread(void) {}
> 
> Signed-off-by: Srinivasarao Pathipati <quic_c_spathi@quicinc.com>
> ---
>  kernel/rcu/tasks.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h
> index 8b51e6a..53ddb4e 100644
> --- a/kernel/rcu/tasks.h
> +++ b/kernel/rcu/tasks.h
> @@ -707,7 +707,7 @@ static void show_rcu_tasks_rude_gp_kthread(void)
>  #endif /* #ifndef CONFIG_TINY_RCU */
>  
>  #else /* #ifdef CONFIG_TASKS_RUDE_RCU */
> -static void show_rcu_tasks_rude_gp_kthread(void) {}
> +static inline void show_rcu_tasks_rude_gp_kthread(void) {}
>  #endif /* #else #ifdef CONFIG_TASKS_RUDE_RCU */
>  
>  ////////////////////////////////////////////////////////////////////////
> -- 
> 2.7.4
> 

What commit id caused this problem?

And why isn't it an issue in newer kernels, what commit id fixed it and
why can't we just take that instead?

thanks,

greg k-h