Re: [ammarfaizi2-block:paulmck/linux-rcu/dev 53/55] include/linux/rcupdate.h:207:34: error: implicit declaration of function 'rcu_tasks_trace_qs'; did you mean 'rcu_tasks_classic_qs'?

["Paul E. McKenney" <paulmck@kernel.org>]

On Thu, May 19, 2022 at 10:42:19AM +0800, kernel test robot wrote:
> tree:   https://github.com/ammarfaizi2/linux-block paulmck/linux-rcu/dev
> head:   b2a7e376a9dcfa2de46236696dfdd48275edf63d
> commit: 840470b0e655a13aae153f3b46d1e02fadf5c06a [53/55] fixup! tasks-rcu: Track blocked RCU Tasks Trace readers
> config: um-i386_defconfig (https://download.01.org/0day-ci/archive/20220519/202205191043.pLKc0AwM-lkp@intel.com/config)
> compiler: gcc-11 (Debian 11.2.0-20) 11.2.0
> reproduce (this is a W=1 build):
>         # https://github.com/ammarfaizi2/linux-block/commit/840470b0e655a13aae153f3b46d1e02fadf5c06a
>         git remote add ammarfaizi2-block https://github.com/ammarfaizi2/linux-block
>         git fetch --no-tags ammarfaizi2-block paulmck/linux-rcu/dev
>         git checkout 840470b0e655a13aae153f3b46d1e02fadf5c06a
>         # save the config file
>         mkdir build_dir && cp config build_dir/.config
>         make W=1 O=build_dir ARCH=um SUBARCH=i386 SHELL=/bin/bash
> 
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>

Good catch, fix is not on -rcu and will be folded into the original
with attribution.

							Thanx, Paul

> All errors (new ones prefixed by >>):
> 
>    kernel/sched/core.c:5235:20: warning: no previous prototype for 'task_sched_runtime' [-Wmissing-prototypes]
>     5235 | unsigned long long task_sched_runtime(struct task_struct *p)
>          |                    ^~~~~~~~~~~~~~~~~~
>    In file included from include/linux/rculist.h:11,
>                     from include/linux/dcache.h:8,
>                     from include/linux/fs.h:8,
>                     from include/linux/highmem.h:5,
>                     from kernel/sched/core.c:9:
>    kernel/sched/core.c: In function '__schedule':
> >> include/linux/rcupdate.h:207:34: error: implicit declaration of function 'rcu_tasks_trace_qs'; did you mean 'rcu_tasks_classic_qs'? [-Werror=implicit-function-declaration]
>      207 | #define rcu_tasks_qs(t, preempt) rcu_tasks_trace_qs(t);
>          |                                  ^~~~~~~~~~~~~~~~~~
>    include/linux/rcutiny.h:74:17: note: in expansion of macro 'rcu_tasks_qs'
>       74 |                 rcu_tasks_qs(current, (preempt)); \
>          |                 ^~~~~~~~~~~~
>    kernel/sched/core.c:6279:9: note: in expansion of macro 'rcu_note_context_switch'
>     6279 |         rcu_note_context_switch(!!sched_mode);
>          |         ^~~~~~~~~~~~~~~~~~~~~~~
>    kernel/sched/core.c: At top level:
>    kernel/sched/core.c:9432:13: warning: no previous prototype for 'sched_init_smp' [-Wmissing-prototypes]
>     9432 | void __init sched_init_smp(void)
>          |             ^~~~~~~~~~~~~~
>    kernel/sched/core.c:9460:13: warning: no previous prototype for 'sched_init' [-Wmissing-prototypes]
>     9460 | void __init sched_init(void)
>          |             ^~~~~~~~~~
>    cc1: some warnings being treated as errors
> 
> 
> vim +207 include/linux/rcupdate.h
> 
>    201	
>    202	#define rcu_note_voluntary_context_switch(t) rcu_tasks_qs(t, false)
>    203	void exit_tasks_rcu_start(void);
>    204	void exit_tasks_rcu_finish(void);
>    205	#else /* #ifdef CONFIG_TASKS_RCU_GENERIC */
>    206	#define rcu_tasks_classic_qs(t, preempt) do { } while (0)
>  > 207	#define rcu_tasks_qs(t, preempt) rcu_tasks_trace_qs(t);
>    208	#define rcu_note_voluntary_context_switch(t) do { } while (0)
>    209	#define call_rcu_tasks call_rcu
>    210	#define synchronize_rcu_tasks synchronize_rcu
>    211	static inline void exit_tasks_rcu_start(void) { }
>    212	static inline void exit_tasks_rcu_finish(void) { }
>    213	#endif /* #else #ifdef CONFIG_TASKS_RCU_GENERIC */
>    214	
> 
> -- 
> 0-DAY CI Kernel Test Service
> https://01.org/lkp