On Fri, Jun 09, 2023 at 02:05:14PM +0200, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@xxxxxxxx>
>
> Both the CONFIG_TASKS_RCU and CONFIG_TASKS_RUDE_RCU options
> are broken when RCU_TINY is enabled as well, as some functions
> are missing a declaration.
>
> In file included from kernel/rcu/update.c:649:
> kernel/rcu/tasks.h:1271:21: error: no previous prototype for 'get_rcu_tasks_rude_gp_kthread' [-Werror=missing-prototypes]
> 1271 | struct task_struct *get_rcu_tasks_rude_gp_kthread(void)
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> kernel/rcu/rcuscale.c:330:27: error: 'get_rcu_tasks_rude_gp_kthread' undeclared here (not in a function); did you mean 'get_rcu_tasks_trace_gp_kthread'?
> 330 | .rso_gp_kthread = get_rcu_tasks_rude_gp_kthread,
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> | get_rcu_tasks_trace_gp_kthread
>
> In file included from /home/arnd/arm-soc/kernel/rcu/update.c:649:
> kernel/rcu/tasks.h:1113:21: error: no previous prototype for 'get_rcu_tasks_gp_kthread' [-Werror=missing-prototypes]
> 1113 | struct task_struct *get_rcu_tasks_gp_kthread(void)
> | ^~~~~~~~~~~~~~~~~~~~~~~~
>
> Also, building with CONFIG_TASKS_RUDE_RCU but not CONFIG_TASKS_RCU is
> broken because of some missing stub functions:
>
> kernel/rcu/rcuscale.c:322:27: error: 'tasks_scale_read_lock' undeclared here (not in a function); did you mean 'srcu_scale_read_lock'?
> 322 | .readlock = tasks_scale_read_lock,
> | ^~~~~~~~~~~~~~~~~~~~~
> | srcu_scale_read_lock
> kernel/rcu/rcuscale.c:323:27: error: 'tasks_scale_read_unlock' undeclared here (not in a function); did you mean 'srcu_scale_read_unlock'?
> 323 | .readunlock = tasks_scale_read_unlock,
> | ^~~~~~~~~~~~~~~~~~~~~~~
> | srcu_scale_read_unlock
>
> Move the declarations outside of the RCU_TINY #ifdef and duplicate the
> shared stub functions to address all of the above.
>
> Fixes: 88d7ff818f0ce ("rcuscale: Add RCU Tasks Rude testing")
> Fixes: 755f1c5eb416b ("rcuscale: Measure RCU Tasks Trace grace-period kthread CPU time")
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Queued and pushed, thank you!
I clearly need to improve my Kconfig coverage here...
Thanx, Paul
> ---
> kernel/rcu/rcu.h | 14 ++++++++------
> kernel/rcu/rcuscale.c | 13 +++++++++++--
> 2 files changed, 19 insertions(+), 8 deletions(-)
>
> diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h
> index 9829d8161b213..5befd8780dcd3 100644
> --- a/kernel/rcu/rcu.h
> +++ b/kernel/rcu/rcu.h
> @@ -505,18 +505,20 @@ void rcu_async_relax(void);
> void rcupdate_announce_bootup_oddness(void);
> #ifdef CONFIG_TASKS_RCU_GENERIC
> void show_rcu_tasks_gp_kthreads(void);
> -# ifdef CONFIG_TASKS_RCU
> -struct task_struct *get_rcu_tasks_gp_kthread(void);
> -# endif // # ifdef CONFIG_TASKS_RCU
> -# ifdef CONFIG_TASKS_RUDE_RCU
> -struct task_struct *get_rcu_tasks_rude_gp_kthread(void);
> -# endif // # ifdef CONFIG_TASKS_RUDE_RCU
> #else /* #ifdef CONFIG_TASKS_RCU_GENERIC */
> static inline void show_rcu_tasks_gp_kthreads(void) {}
> #endif /* #else #ifdef CONFIG_TASKS_RCU_GENERIC */
> void rcu_request_urgent_qs_task(struct task_struct *t);
> #endif /* #else #ifdef CONFIG_TINY_RCU */
>
> +#ifdef CONFIG_TASKS_RCU
> +struct task_struct *get_rcu_tasks_gp_kthread(void);
> +#endif // # ifdef CONFIG_TASKS_RCU
> +
> +#ifdef CONFIG_TASKS_RUDE_RCU
> +struct task_struct *get_rcu_tasks_rude_gp_kthread(void);
> +#endif // # ifdef CONFIG_TASKS_RUDE_RCU
> +
> #define RCU_SCHEDULER_INACTIVE 0
> #define RCU_SCHEDULER_INIT 1
> #define RCU_SCHEDULER_RUNNING 2
> diff --git a/kernel/rcu/rcuscale.c b/kernel/rcu/rcuscale.c
> index 5ce3b4e7ce711..a0eae19007088 100644
> --- a/kernel/rcu/rcuscale.c
> +++ b/kernel/rcu/rcuscale.c
> @@ -316,11 +316,20 @@ static struct rcu_scale_ops tasks_ops = {
> * Definitions for RCU-tasks-rude scalability testing.
> */
>
> +static int tasks_rude_scale_read_lock(void)
> +{
> + return 0;
> +}
> +
> +static void tasks_rude_scale_read_unlock(int idx)
> +{
> +}
> +
> static struct rcu_scale_ops tasks_rude_ops = {
> .ptype = RCU_TASKS_RUDE_FLAVOR,
> .init = rcu_sync_scale_init,
> - .readlock = tasks_scale_read_lock,
> - .readunlock = tasks_scale_read_unlock,
> + .readlock = tasks_rude_scale_read_lock,
> + .readunlock = tasks_rude_scale_read_unlock,
> .get_gp_seq = rcu_no_completed,
> .gp_diff = rcu_seq_diff,
> .async = call_rcu_tasks_rude,
> --
> 2.39.2
>
