Paul-
On 6/9/23 15:51, Paul E. McKenney wrote:
> 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...
>
Pushed where. I'm still seeing this build error in linux-next 20230613.
Thanks.
>
>> ---
>> 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
>>
--
~Randy
