Re: [PATCH 12/12] hugetlb: batch TLB flushes when restoring vmemmap

Re: [PATCH 12/12] hugetlb: batch TLB flushes when restoring vmemmap

[kernel test robot]

Hi Mike,

kernel test robot noticed the following build warnings:

[auto build test WARNING on next-20230825]
[cannot apply to akpm-mm/mm-everything v6.5-rc7 v6.5-rc6 v6.5-rc5 linus/master v6.5-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/Mike-Kravetz/hugetlb-clear-flags-in-tail-pages-that-will-be-freed-individually/20230826-030805
base:   next-20230825
patch link:    https://lore.kernel.org/r/20230825190436.55045-13-mike.kravetz%40oracle.com
patch subject: [PATCH 12/12] hugetlb: batch TLB flushes when restoring vmemmap
config: s390-randconfig-001-20230826 (https://download.01.org/0day-ci/archive/20230826/202308261516.F6FBNktd-lkp@intel.com/config)
compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project.git 4a5ac14ee968ff0ad5d2cc1ffa0299048db4c88a)
reproduce: (https://download.01.org/0day-ci/archive/20230826/202308261516.F6FBNktd-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/202308261516.F6FBNktd-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> mm/hugetlb_vmemmap.c:516:5: warning: no previous prototype for function '__hugetlb_vmemmap_restore' [-Wmissing-prototypes]
     516 | int __hugetlb_vmemmap_restore(const struct hstate *h, struct page *head, bool bulk)
         |     ^
   mm/hugetlb_vmemmap.c:516:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
     516 | int __hugetlb_vmemmap_restore(const struct hstate *h, struct page *head, bool bulk)
         | ^
         | static 
   mm/hugetlb_vmemmap.c:567:28: error: use of undeclared identifier 'TLB_FLUSH_ALL'
     567 |         flush_tlb_kernel_range(0, TLB_FLUSH_ALL);
         |                                   ^
   mm/hugetlb_vmemmap.c:673:6: warning: no previous prototype for function 'hugetlb_vmemmap_optimize_bulk' [-Wmissing-prototypes]
     673 | void hugetlb_vmemmap_optimize_bulk(const struct hstate *h, struct page *head,
         |      ^
   mm/hugetlb_vmemmap.c:673:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
     673 | void hugetlb_vmemmap_optimize_bulk(const struct hstate *h, struct page *head,
         | ^
         | static 
   mm/hugetlb_vmemmap.c:679:6: warning: no previous prototype for function 'hugetlb_vmemmap_split' [-Wmissing-prototypes]
     679 | void hugetlb_vmemmap_split(const struct hstate *h, struct page *head)
         |      ^
   mm/hugetlb_vmemmap.c:679:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
     679 | void hugetlb_vmemmap_split(const struct hstate *h, struct page *head)
         | ^
         | static 
   mm/hugetlb_vmemmap.c:710:28: error: use of undeclared identifier 'TLB_FLUSH_ALL'
     710 |         flush_tlb_kernel_range(0, TLB_FLUSH_ALL);
         |                                   ^
   mm/hugetlb_vmemmap.c:715:28: error: use of undeclared identifier 'TLB_FLUSH_ALL'
     715 |         flush_tlb_kernel_range(0, TLB_FLUSH_ALL);
         |                                   ^
   3 warnings and 3 errors generated.


vim +/__hugetlb_vmemmap_restore +516 mm/hugetlb_vmemmap.c

   515	
 > 516	int __hugetlb_vmemmap_restore(const struct hstate *h, struct page *head, bool bulk)
   517	{
   518		int ret;
   519		unsigned long vmemmap_start = (unsigned long)head, vmemmap_end;
   520		unsigned long vmemmap_reuse;
   521	
   522		if (!HPageVmemmapOptimized(head))
   523			return 0;
   524	
   525		vmemmap_end	= vmemmap_start + hugetlb_vmemmap_size(h);
   526		vmemmap_reuse	= vmemmap_start;
   527		vmemmap_start	+= HUGETLB_VMEMMAP_RESERVE_SIZE;
   528	
   529		/*
   530		 * The pages which the vmemmap virtual address range [@vmemmap_start,
   531		 * @vmemmap_end) are mapped to are freed to the buddy allocator, and
   532		 * the range is mapped to the page which @vmemmap_reuse is mapped to.
   533		 * When a HugeTLB page is freed to the buddy allocator, previously
   534		 * discarded vmemmap pages must be allocated and remapping.
   535		 */
   536		ret = vmemmap_remap_alloc(vmemmap_start, vmemmap_end, vmemmap_reuse, bulk);
   537		if (!ret) {
   538			ClearHPageVmemmapOptimized(head);
   539			static_branch_dec(&hugetlb_optimize_vmemmap_key);
   540		}
   541	
   542		return ret;
   543	}
   544	

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