Re: [PATCH v2] rcu: Keeping rcu-related kthreads running on housekeeping CPUS

[kernel test robot]

Hi Zqiang,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on paulmck-rcu/dev]
[also build test WARNING on next-20230209]
[cannot apply to linus/master v6.2-rc7]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Zqiang/rcu-Keeping-rcu-related-kthreads-running-on-housekeeping-CPUS/20230209-182311
base:   https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev
patch link:    https://lore.kernel.org/r/20230209102730.974465-1-qiang1.zhang%40intel.com
patch subject: [PATCH v2] rcu: Keeping rcu-related kthreads running on housekeeping CPUS
config: m68k-allyesconfig (https://download.01.org/0day-ci/archive/20230209/202302092354.9PFOG9CE-lkp@xxxxxxxxx/config)
compiler: m68k-linux-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/intel-lab-lkp/linux/commit/af15a3ade363b21d823918088623f8564cbd9d08
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Zqiang/rcu-Keeping-rcu-related-kthreads-running-on-housekeeping-CPUS/20230209-182311
        git checkout af15a3ade363b21d823918088623f8564cbd9d08
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=m68k olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=m68k SHELL=/bin/bash kernel/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Link: https://lore.kernel.org/oe-kbuild-all/202302092354.9PFOG9CE-lkp@xxxxxxxxx/

All warnings (new ones prefixed by >>):

   In file included from kernel/torture.c:40:
>> kernel/rcu/rcu.h:602:6: warning: no previous prototype for 'rcu_kthread_setaffinity' [-Wmissing-prototypes]
     602 | void rcu_kthread_setaffinity(struct task_struct *tsk, int outgoing) { }
         |      ^~~~~~~~~~~~~~~~~~~~~~~
--
   In file included from kernel/rcu/update.c:49:
>> kernel/rcu/rcu.h:602:6: warning: no previous prototype for 'rcu_kthread_setaffinity' [-Wmissing-prototypes]
     602 | void rcu_kthread_setaffinity(struct task_struct *tsk, int outgoing) { }
         |      ^~~~~~~~~~~~~~~~~~~~~~~
   In file included from kernel/rcu/update.c:649:
>> kernel/rcu/tasks.h:1970:6: warning: no previous prototype for 'rcu_tasks_generic_setaffinity' [-Wmissing-prototypes]
    1970 | void rcu_tasks_generic_setaffinity(int cpu)
         |      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~


vim +/rcu_kthread_setaffinity +602 kernel/rcu/rcu.h

   588	
   589	#ifdef CONFIG_TINY_RCU
   590	static inline bool rcu_dynticks_zero_in_eqs(int cpu, int *vp) { return false; }
   591	static inline unsigned long rcu_get_gp_seq(void) { return 0; }
   592	static inline unsigned long rcu_exp_batches_completed(void) { return 0; }
   593	static inline unsigned long
   594	srcu_batches_completed(struct srcu_struct *sp) { return 0; }
   595	static inline void rcu_force_quiescent_state(void) { }
   596	static inline bool rcu_check_boost_fail(unsigned long gp_state, int *cpup) { return true; }
   597	static inline void show_rcu_gp_kthreads(void) { }
   598	static inline int rcu_get_gp_kthreads_prio(void) { return 0; }
   599	static inline void rcu_fwd_progress_check(unsigned long j) { }
   600	static inline void rcu_gp_slow_register(atomic_t *rgssp) { }
   601	static inline void rcu_gp_slow_unregister(atomic_t *rgssp) { }
 > 602	void rcu_kthread_setaffinity(struct task_struct *tsk, int outgoing) { }
   603	#else /* #ifdef CONFIG_TINY_RCU */
   604	bool rcu_dynticks_zero_in_eqs(int cpu, int *vp);
   605	unsigned long rcu_get_gp_seq(void);
   606	unsigned long rcu_exp_batches_completed(void);
   607	unsigned long srcu_batches_completed(struct srcu_struct *sp);
   608	bool rcu_check_boost_fail(unsigned long gp_state, int *cpup);
   609	void show_rcu_gp_kthreads(void);
   610	int rcu_get_gp_kthreads_prio(void);
   611	void rcu_fwd_progress_check(unsigned long j);
   612	void rcu_force_quiescent_state(void);
   613	void rcu_kthread_setaffinity(struct task_struct *tsk, int outgoing);
   614	extern struct workqueue_struct *rcu_gp_wq;
   615	#ifdef CONFIG_RCU_EXP_KTHREAD
   616	extern struct kthread_worker *rcu_exp_gp_kworker;
   617	extern struct kthread_worker *rcu_exp_par_gp_kworker;
   618	#else /* !CONFIG_RCU_EXP_KTHREAD */
   619	extern struct workqueue_struct *rcu_par_gp_wq;
   620	#endif /* CONFIG_RCU_EXP_KTHREAD */
   621	void rcu_gp_slow_register(atomic_t *rgssp);
   622	void rcu_gp_slow_unregister(atomic_t *rgssp);
   623	#endif /* #else #ifdef CONFIG_TINY_RCU */
   624	

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