Re: [PATCH v5 4/4] mm: Introduce per-thpsize swapin control policy

[Barry Song <21cnbao@gmail.com>]

On Sat, Jul 27, 2024 at 5:58 PM kernel test robot <lkp@intel.com> wrote:
>
> Hi Barry,
>
> kernel test robot noticed the following build warnings:
>
> [auto build test WARNING on akpm-mm/mm-everything]

Hi Thanks!
Would you check if the below patch fixes the problem?

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 41460847988c..06984a325af7 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -80,7 +80,7 @@ unsigned long huge_zero_pfn __read_mostly = ~0UL;
 unsigned long huge_anon_orders_always __read_mostly;
 unsigned long huge_anon_orders_madvise __read_mostly;
 unsigned long huge_anon_orders_inherit __read_mostly;
-unsigned long huge_anon_orders_swapin_always __read_mostly;
+static unsigned long huge_anon_orders_swapin_always __read_mostly;
 
 unsigned long __thp_vma_allowable_orders(struct vm_area_struct *vma,
 					 unsigned long vm_flags,
>
> url:    https://github.com/intel-lab-lkp/linux/commits/Barry-Song/mm-swap-introduce-swapcache_prepare_nr-and-swapcache_clear_nr-for-large-folios-swap-in/20240726-181412
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
> patch link:    https://lore.kernel.org/r/20240726094618.401593-5-21cnbao%40gmail.com
> patch subject: [PATCH v5 4/4] mm: Introduce per-thpsize swapin control policy
> config: x86_64-randconfig-121-20240727 (https://download.01.org/0day-ci/archive/20240727/202407271351.ffZPMT6W-lkp@intel.com/config)
> compiler: gcc-11 (Ubuntu 11.4.0-4ubuntu1) 11.4.0
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240727/202407271351.ffZPMT6W-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/202407271351.ffZPMT6W-lkp@intel.com/
>
> sparse warnings: (new ones prefixed by >>)
> >> mm/huge_memory.c:83:15: sparse: sparse: symbol 'huge_anon_orders_swapin_always' was not declared. Should it be static?
>    mm/huge_memory.c: note: in included file (through include/linux/smp.h, include/linux/lockdep.h, include/linux/spinlock.h, ...):
>    include/linux/list.h:83:21: sparse: sparse: self-comparison always evaluates to true
>    mm/huge_memory.c: note: in included file (through include/linux/mmzone.h, include/linux/gfp.h, include/linux/mm.h):
>    include/linux/page-flags.h:235:46: sparse: sparse: self-comparison always evaluates to false
>    include/linux/page-flags.h:235:46: sparse: sparse: self-comparison always evaluates to false
>    mm/huge_memory.c:1867:20: sparse: sparse: context imbalance in 'madvise_free_huge_pmd' - unexpected unlock
>    include/linux/page-flags.h:235:46: sparse: sparse: self-comparison always evaluates to false
>    mm/huge_memory.c:1905:28: sparse: sparse: context imbalance in 'zap_huge_pmd' - unexpected unlock
>    mm/huge_memory.c:2016:28: sparse: sparse: context imbalance in 'move_huge_pmd' - unexpected unlock
>    mm/huge_memory.c:2156:20: sparse: sparse: context imbalance in 'change_huge_pmd' - unexpected unlock
>    mm/huge_memory.c:2306:12: sparse: sparse: context imbalance in '__pmd_trans_huge_lock' - wrong count at exit
>    mm/huge_memory.c:2323:12: sparse: sparse: context imbalance in '__pud_trans_huge_lock' - wrong count at exit
>    mm/huge_memory.c:2347:28: sparse: sparse: context imbalance in 'zap_huge_pud' - unexpected unlock
>    mm/huge_memory.c:2426:18: sparse: sparse: context imbalance in '__split_huge_zero_page_pmd' - unexpected unlock
>    mm/huge_memory.c:2640:18: sparse: sparse: context imbalance in '__split_huge_pmd_locked' - unexpected unlock
>    include/linux/page-flags.h:235:46: sparse: sparse: self-comparison always evaluates to false
>    mm/huge_memory.c: note: in included file (through include/linux/smp.h, include/linux/lockdep.h, include/linux/spinlock.h, ...):
>    include/linux/list.h:83:21: sparse: sparse: self-comparison always evaluates to true
>    include/linux/list.h:83:21: sparse: sparse: self-comparison always evaluates to true
>    mm/huge_memory.c: note: in included file (through include/linux/mmzone.h, include/linux/gfp.h, include/linux/mm.h):
>    include/linux/page-flags.h:235:46: sparse: sparse: self-comparison always evaluates to false
>    mm/huge_memory.c:3031:30: sparse: sparse: context imbalance in '__split_huge_page' - unexpected unlock
>    mm/huge_memory.c:3306:17: sparse: sparse: context imbalance in 'split_huge_page_to_list_to_order' - different lock contexts for basic block
>    mm/huge_memory.c: note: in included file (through include/linux/smp.h, include/linux/lockdep.h, include/linux/spinlock.h, ...):
>    include/linux/list.h:83:21: sparse: sparse: self-comparison always evaluates to true
>    mm/huge_memory.c: note: in included file (through include/linux/mmzone.h, include/linux/gfp.h, include/linux/mm.h):
>    include/linux/page-flags.h:235:46: sparse: sparse: self-comparison always evaluates to false
>    mm/huge_memory.c: note: in included file (through include/linux/smp.h, include/linux/lockdep.h, include/linux/spinlock.h, ...):
>    include/linux/list.h:83:21: sparse: sparse: self-comparison always evaluates to true
>    mm/huge_memory.c: note: in included file (through include/linux/mmzone.h, include/linux/gfp.h, include/linux/mm.h):
>    include/linux/page-flags.h:235:46: sparse: sparse: self-comparison always evaluates to false
>    include/linux/page-flags.h:235:46: sparse: sparse: self-comparison always evaluates to false
>
> vim +/huge_anon_orders_swapin_always +83 mm/huge_memory.c
>
>     51 
>     52  /*
>     53   * By default, transparent hugepage support is disabled in order to avoid
>     54   * risking an increased memory footprint for applications that are not
>     55   * guaranteed to benefit from it. When transparent hugepage support is
>     56   * enabled, it is for all mappings, and khugepaged scans all mappings.
>     57   * Defrag is invoked by khugepaged hugepage allocations and by page faults
>     58   * for all hugepage allocations.
>     59   */
>     60  unsigned long transparent_hugepage_flags __read_mostly =
>     61  #ifdef CONFIG_TRANSPARENT_HUGEPAGE_ALWAYS
>     62          (1<<TRANSPARENT_HUGEPAGE_FLAG)|
>     63  #endif
>     64  #ifdef CONFIG_TRANSPARENT_HUGEPAGE_MADVISE
>     65          (1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG)|
>     66  #endif
>     67          (1<<TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG)|
>     68          (1<<TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG)|
>     69          (1<<TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG);
>     70 
>     71  static struct shrinker *deferred_split_shrinker;
>     72  static unsigned long deferred_split_count(struct shrinker *shrink,
>     73                                            struct shrink_control *sc);
>     74  static unsigned long deferred_split_scan(struct shrinker *shrink,
>     75                                           struct shrink_control *sc);
>     76 
>     77  static atomic_t huge_zero_refcount;
>     78  struct folio *huge_zero_folio __read_mostly;
>     79  unsigned long huge_zero_pfn __read_mostly = ~0UL;
>     80  unsigned long huge_anon_orders_always __read_mostly;
>     81  unsigned long huge_anon_orders_madvise __read_mostly;
>     82  unsigned long huge_anon_orders_inherit __read_mostly;
>   > 83  unsigned long huge_anon_orders_swapin_always __read_mostly;
>     84 
>
> --
> 0-DAY CI Kernel Test Service
> https://github.com/intel/lkp-tests/wiki

Thanks
Barry