On 26/08/2023 06:56, kernel test robot wrote: > Hi Mike, > > kernel test robot noticed the following build errors: > > [auto build test ERROR 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/20230825190436.55045-11-mike.kravetz%40oracle.com > patch subject: [PATCH 10/12] hugetlb: batch PMD split for bulk vmemmap dedup > config: s390-randconfig-001-20230826 (https://download.01.org/0day-ci/archive/20230826/202308261325.ipTttZHZ-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/20230826/202308261325.ipTttZHZ-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/202308261325.ipTttZHZ-lkp@xxxxxxxxx/ > > All error/warnings (new ones prefixed by >>): > [...] >>> mm/hugetlb_vmemmap.c:698:28: error: use of undeclared identifier 'TLB_FLUSH_ALL' > 698 | flush_tlb_kernel_range(0, TLB_FLUSH_ALL); > | ^ > 2 warnings and 1 error generated. > > TLB_FLUSH_ALL is x86 only so what I wrote above is wrong in what should be architecture independent. The way I should have written the global TLB flush is to use flush_tlb_all(), which is what is implemented by the arch. The alternative is to compose a start/end tuple in the top-level optimize-folios function as we iterate over folios to remap, and flush via flush_tlb_kernel_range(). But this would likely only be relevant on x86 only, that is to optimize the flushing of 3 contiguous 2M hugetlb pages (~24 vmemmap pages) as that's where the TLB flush ceiling is put (31 pages) for per-page VA flush, before falling back to a global TLB flush. Weren't sure of the added complexity for dubious benefit thus kept it in global TLB flush. > vim +/TLB_FLUSH_ALL +698 mm/hugetlb_vmemmap.c > > 666 > > 667 void hugetlb_vmemmap_split(const struct hstate *h, struct page *head) > 668 { > 669 unsigned long vmemmap_start = (unsigned long)head, vmemmap_end; > 670 unsigned long vmemmap_reuse; > 671 > 672 if (!vmemmap_should_optimize(h, head)) > 673 return; > 674 > 675 static_branch_inc(&hugetlb_optimize_vmemmap_key); > 676 > 677 vmemmap_end = vmemmap_start + hugetlb_vmemmap_size(h); > 678 vmemmap_reuse = vmemmap_start; > 679 vmemmap_start += HUGETLB_VMEMMAP_RESERVE_SIZE; > 680 > 681 /* > 682 * Remap the vmemmap virtual address range [@vmemmap_start, @vmemmap_end) > 683 * to the page which @vmemmap_reuse is mapped to, then free the pages > 684 * which the range [@vmemmap_start, @vmemmap_end] is mapped to. > 685 */ > 686 if (vmemmap_remap_split(vmemmap_start, vmemmap_end, vmemmap_reuse)) > 687 static_branch_dec(&hugetlb_optimize_vmemmap_key); > 688 } > 689 > 690 void hugetlb_vmemmap_optimize_folios(struct hstate *h, struct list_head *folio_list) > 691 { > 692 struct folio *folio; > 693 LIST_HEAD(vmemmap_pages); > 694 > 695 list_for_each_entry(folio, folio_list, lru) > 696 hugetlb_vmemmap_split(h, &folio->page); > 697 > > 698 flush_tlb_kernel_range(0, TLB_FLUSH_ALL); > 699 > 700 list_for_each_entry(folio, folio_list, lru) > 701 hugetlb_vmemmap_optimize_bulk(h, &folio->page, &vmemmap_pages); > 702 > 703 free_vmemmap_page_list(&vmemmap_pages); > 704 } > 705 >
