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

From: kernel test robot
Date: Sat Aug 26 2023 - 04:02:46 EST


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@xxxxxxxxx/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@xxxxxxxxx/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@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202308261516.F6FBNktd-lkp@xxxxxxxxx/

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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