Re: [PATCH 3/3] mm/swap: integrate swap tier infrastructure into swap subsystem

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

Hi Youngjun,

kernel test robot noticed the following build errors:

[auto build test ERROR on akpm-mm/mm-everything]

url:    https://github.com/intel-lab-lkp/linux/commits/Youngjun-Park/mm-swap-introduce-swap-tier-infrastructure/20251109-215033
base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link:    https://lore.kernel.org/r/20251109124947.1101520-4-youngjun.park%40lge.com
patch subject: [PATCH 3/3] mm/swap: integrate swap tier infrastructure into swap subsystem
config: s390-randconfig-001-20251110 (https://download.01.org/0day-ci/archive/20251110/202511102053.StJy9JAB-lkp@intel.com/config)
compiler: s390-linux-gcc (GCC) 8.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251110/202511102053.StJy9JAB-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/202511102053.StJy9JAB-lkp@intel.com/

All errors (new ones prefixed by >>):

   In file included from mm/page_io.c:29:
>> mm/swap_tier.h:71:1: error: expected identifier or '(' before '{' token
    {
    ^
   mm/swap_tier.h:70:19: warning: 'swap_tiers_collect_compare_mask' declared 'static' but never defined [-Wunused-function]
    static inline int swap_tiers_collect_compare_mask(struct mem_cgroup *memcg);
                      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
--
   In file included from mm/swapfile.c:52:
>> mm/swap_tier.h:71:1: error: expected identifier or '(' before '{' token
    {
    ^
   mm/swapfile.c: In function 'swap_alloc_entry':
>> mm/swapfile.c:1309:29: error: 'struct swap_info_struct' has no member named 'tier_idx'
      if (swap_tiers_test_off(si->tier_idx, mask))
                                ^~
   In file included from mm/swapfile.c:52:
   mm/swapfile.c: At top level:
   mm/swap_tier.h:70:19: warning: 'swap_tiers_collect_compare_mask' used but never defined
    static inline int swap_tiers_collect_compare_mask(struct mem_cgroup *memcg);
                      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
--
   In file included from mm/memcontrol.c:71:
>> mm/swap_tier.h:71:1: error: expected identifier or '(' before '{' token
    {
    ^
   mm/memcontrol.c: In function 'mem_cgroup_free':
>> mm/memcontrol.c:3734:2: error: implicit declaration of function 'swap_tiers_put_mask'; did you mean 'swap_tiers_release'? [-Werror=implicit-function-declaration]
     swap_tiers_put_mask(memcg);
     ^~~~~~~~~~~~~~~~~~~
     swap_tiers_release
   In file included from mm/memcontrol.c:71:
   mm/memcontrol.c: At top level:
   mm/swap_tier.h:70:19: warning: 'swap_tiers_collect_compare_mask' declared 'static' but never defined [-Wunused-function]
    static inline int swap_tiers_collect_compare_mask(struct mem_cgroup *memcg);
                      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   cc1: some warnings being treated as errors

Kconfig warnings: (for reference only)
   WARNING: unmet direct dependencies detected for OF_GPIO
   Depends on [n]: GPIOLIB [=y] && OF [=y] && HAS_IOMEM [=n]
   Selected by [y]:
   - REGULATOR_RT5133 [=y] && REGULATOR [=y] && I2C [=y] && GPIOLIB [=y] && OF [=y]


vim +71 mm/swap_tier.h

c17fe68325c921 Youngjun Park 2025-11-09  41  
c17fe68325c921 Youngjun Park 2025-11-09  42  void swap_tiers_init(void);
c17fe68325c921 Youngjun Park 2025-11-09  43  int swap_tiers_add(struct tiers_desc desc[], int nr);
c17fe68325c921 Youngjun Park 2025-11-09  44  int swap_tiers_remove(struct tiers_desc desc[], int nr);
c17fe68325c921 Youngjun Park 2025-11-09  45  ssize_t swap_tiers_show_sysfs(char *buf);
c17fe68325c921 Youngjun Park 2025-11-09  46  void swap_tiers_show_memcg(struct seq_file *m, struct mem_cgroup *memcg);
c17fe68325c921 Youngjun Park 2025-11-09  47  void swap_tiers_assign(struct swap_info_struct *swp);
c17fe68325c921 Youngjun Park 2025-11-09  48  void swap_tiers_release(struct swap_info_struct *swp);
c17fe68325c921 Youngjun Park 2025-11-09  49  int swap_tiers_get_mask(struct tiers_desc *desc, int nr, struct mem_cgroup *memcg);
c17fe68325c921 Youngjun Park 2025-11-09  50  void swap_tiers_put_mask(struct mem_cgroup *memcg);
c17fe68325c921 Youngjun Park 2025-11-09  51  static inline bool swap_tiers_test_off(int tier_idx, int mask)
c17fe68325c921 Youngjun Park 2025-11-09  52  {
c17fe68325c921 Youngjun Park 2025-11-09  53  	return TIER_MASK(tier_idx, TIER_OFF_MASK) & mask;
c17fe68325c921 Youngjun Park 2025-11-09  54  }
c17fe68325c921 Youngjun Park 2025-11-09  55  int swap_tiers_collect_compare_mask(struct mem_cgroup *memcg);
c17fe68325c921 Youngjun Park 2025-11-09  56  #else
c17fe68325c921 Youngjun Park 2025-11-09  57  static inline void swap_tiers_init(void)
c17fe68325c921 Youngjun Park 2025-11-09  58  {
c17fe68325c921 Youngjun Park 2025-11-09  59  }
c17fe68325c921 Youngjun Park 2025-11-09  60  static inline void swap_tiers_assign(struct swap_info_struct *swp)
c17fe68325c921 Youngjun Park 2025-11-09  61  {
c17fe68325c921 Youngjun Park 2025-11-09  62  }
c17fe68325c921 Youngjun Park 2025-11-09  63  static inline void swap_tiers_release(struct swap_info_struct *swp)
c17fe68325c921 Youngjun Park 2025-11-09  64  {
c17fe68325c921 Youngjun Park 2025-11-09  65  }
c17fe68325c921 Youngjun Park 2025-11-09  66  static inline bool swap_tiers_test_off(int tier_off_mask, int mask)
c17fe68325c921 Youngjun Park 2025-11-09  67  {
c17fe68325c921 Youngjun Park 2025-11-09  68  	return false;
c17fe68325c921 Youngjun Park 2025-11-09  69  }
c17fe68325c921 Youngjun Park 2025-11-09  70  static inline int swap_tiers_collect_compare_mask(struct mem_cgroup *memcg);
c17fe68325c921 Youngjun Park 2025-11-09 @71  {

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