Re: [PATCH v6 6/7] mm: Defer TLB flush by keeping both src and dst folios at migration

[kernel test robot <lkp@intel.com>]

Hi Byungchul,

kernel test robot noticed the following build warnings:

[auto build test WARNING on 0dd3ee31125508cd67f7e7172247f05b7fd1753a]

url:    https://github.com/intel-lab-lkp/linux/commits/Byungchul-Park/x86-tlb-Add-APIs-manipulating-tlb-batch-s-arch-data/20240115-162220
base:   0dd3ee31125508cd67f7e7172247f05b7fd1753a
patch link:    https://lore.kernel.org/r/20240115081953.2521-7-byungchul%40sk.com
patch subject: [PATCH v6 6/7] mm: Defer TLB flush by keeping both src and dst folios at migration
config: arm-defconfig (https://download.01.org/0day-ci/archive/20240116/202401160823.I1JCYXT5-lkp@intel.com/config)
compiler: clang version 14.0.6 (https://github.com/llvm/llvm-project.git f28c006a5895fc0e329fe15fead81e37457cb1d1)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240116/202401160823.I1JCYXT5-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202401160823.I1JCYXT5-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In file included from arch/arm/kernel/asm-offsets.c:12:
>> include/linux/mm.h:2046:43: warning: declaration of 'struct arch_tlbflush_unmap_batch' will not be visible outside of this function [-Wvisibility]
   static inline void migrc_flush_end(struct arch_tlbflush_unmap_batch *arch) {}
                                             ^
   1 warning generated.
--
   In file included from kernel/sched/core.c:9:
   In file included from include/linux/highmem.h:8:
   In file included from include/linux/cacheflush.h:5:
   In file included from arch/arm/include/asm/cacheflush.h:10:
>> include/linux/mm.h:2046:43: warning: declaration of 'struct arch_tlbflush_unmap_batch' will not be visible outside of this function [-Wvisibility]
   static inline void migrc_flush_end(struct arch_tlbflush_unmap_batch *arch) {}
                                             ^
   kernel/sched/core.c:6500:20: warning: unused function 'sched_core_cpu_deactivate' [-Wunused-function]
   static inline void sched_core_cpu_deactivate(unsigned int cpu) {}
                      ^
   2 warnings generated.
--
   In file included from kernel/sched/fair.c:27:
   In file included from include/linux/mm_api.h:1:
>> include/linux/mm.h:2046:43: warning: declaration of 'struct arch_tlbflush_unmap_batch' will not be visible outside of this function [-Wvisibility]
   static inline void migrc_flush_end(struct arch_tlbflush_unmap_batch *arch) {}
                                             ^
   kernel/sched/fair.c:13041:6: warning: no previous prototype for function 'free_fair_sched_group' [-Wmissing-prototypes]
   void free_fair_sched_group(struct task_group *tg) { }
        ^
   kernel/sched/fair.c:13041:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   void free_fair_sched_group(struct task_group *tg) { }
   ^
   static 
   kernel/sched/fair.c:13043:5: warning: no previous prototype for function 'alloc_fair_sched_group' [-Wmissing-prototypes]
   int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent)
       ^
   kernel/sched/fair.c:13043:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent)
   ^
   static 
   kernel/sched/fair.c:13048:6: warning: no previous prototype for function 'online_fair_sched_group' [-Wmissing-prototypes]
   void online_fair_sched_group(struct task_group *tg) { }
        ^
   kernel/sched/fair.c:13048:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   void online_fair_sched_group(struct task_group *tg) { }
   ^
   static 
   kernel/sched/fair.c:13050:6: warning: no previous prototype for function 'unregister_fair_sched_group' [-Wmissing-prototypes]
   void unregister_fair_sched_group(struct task_group *tg) { }
        ^
   kernel/sched/fair.c:13050:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   void unregister_fair_sched_group(struct task_group *tg) { }
   ^
   static 
   kernel/sched/fair.c:488:20: warning: unused function 'list_del_leaf_cfs_rq' [-Wunused-function]
   static inline void list_del_leaf_cfs_rq(struct cfs_rq *cfs_rq)
                      ^
   kernel/sched/fair.c:509:19: warning: unused function 'tg_is_idle' [-Wunused-function]
   static inline int tg_is_idle(struct task_group *tg)
                     ^
   kernel/sched/fair.c:533:19: warning: unused function 'max_vruntime' [-Wunused-function]
   static inline u64 max_vruntime(u64 max_vruntime, u64 vruntime)
                     ^
   kernel/sched/fair.c:6518:20: warning: unused function 'cfs_bandwidth_used' [-Wunused-function]
   static inline bool cfs_bandwidth_used(void)
                      ^
   kernel/sched/fair.c:6526:20: warning: unused function 'sync_throttle' [-Wunused-function]
   static inline void sync_throttle(struct task_group *tg, int cpu) {}
                      ^
   kernel/sched/fair.c:6550:37: warning: unused function 'tg_cfs_bandwidth' [-Wunused-function]
   static inline struct cfs_bandwidth *tg_cfs_bandwidth(struct task_group *tg)
                                       ^
   kernel/sched/fair.c:6554:20: warning: unused function 'destroy_cfs_bandwidth' [-Wunused-function]
   static inline void destroy_cfs_bandwidth(struct cfs_bandwidth *cfs_b) {}
                      ^
   12 warnings generated.
--
   In file included from arch/arm/kernel/asm-offsets.c:12:
>> include/linux/mm.h:2046:43: warning: declaration of 'struct arch_tlbflush_unmap_batch' will not be visible outside of this function [-Wvisibility]
   static inline void migrc_flush_end(struct arch_tlbflush_unmap_batch *arch) {}
                                             ^
   1 warning generated.


vim +2046 include/linux/mm.h

  2040	
  2041	#if defined(CONFIG_MIGRATION) && defined(CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH)
  2042	extern void migrc_flush_start(void);
  2043	extern void migrc_flush_end(struct arch_tlbflush_unmap_batch *arch);
  2044	#else
  2045	static inline void migrc_flush_start(void) {}
> 2046	static inline void migrc_flush_end(struct arch_tlbflush_unmap_batch *arch) {}
  2047	#endif
  2048	

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