Hi Liu, Thank you for the patch! Yet something to improve: [auto build test ERROR on akpm-mm/mm-everything] [also build test ERROR on linus/master v5.19-rc8 next-20220726] [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/Liu-Zixian/shmem-support-huge_fault-to-avoid-pmd-split/20220726-212946 base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything config: hexagon-randconfig-r045-20220724 (https://download.01.org/0day-ci/archive/20220727/202207270709.lDgcRjnd-lkp@xxxxxxxxx/config) compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 83882606dbd7ffb0bdd3460356202d97705809c8) reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # https://github.com/intel-lab-lkp/linux/commit/40060ce82c97d38c8e2d71f9d0e4ee818596bb14 git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review Liu-Zixian/shmem-support-huge_fault-to-avoid-pmd-split/20220726-212946 git checkout 40060ce82c97d38c8e2d71f9d0e4ee818596bb14 # save the config file mkdir build_dir && cp config build_dir/.config COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=hexagon SHELL=/bin/bash If you fix the issue, kindly add following tag where applicable Reported-by: kernel test robot <lkp@xxxxxxxxx> All errors (new ones prefixed by >>): >> mm/shmem.c:2164:2: error: call to undeclared function 'copy_user_huge_page'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration] copy_user_huge_page(new_page, old_page, haddr, vmf->vma, HPAGE_PMD_NR); ^ mm/shmem.c:2164:2: note: did you mean 'copy_user_highpage'? include/linux/highmem.h:307:20: note: 'copy_user_highpage' declared here static inline void copy_user_highpage(struct page *to, struct page *from, ^ 1 error generated. vim +/copy_user_huge_page +2164 mm/shmem.c 2132 2133 static vm_fault_t shmem_huge_fault(struct vm_fault *vmf, enum page_entry_size pe_size) 2134 { 2135 vm_fault_t ret = VM_FAULT_FALLBACK; 2136 unsigned long haddr = vmf->address & HPAGE_PMD_MASK; 2137 struct page *old_page, *new_page; 2138 int gfp_flags = GFP_HIGHUSER_MOVABLE | __GFP_COMP; 2139 2140 /* read or shared fault will not split huge pmd */ 2141 if (!(vmf->flags & FAULT_FLAG_WRITE) 2142 || (vmf->vma->vm_flags & VM_SHARED)) 2143 return VM_FAULT_FALLBACK; 2144 if (pe_size != PE_SIZE_PMD) 2145 return VM_FAULT_FALLBACK; 2146 2147 if (pmd_none(*vmf->pmd)) { 2148 if (shmem_fault(vmf) & VM_FAULT_ERROR) 2149 goto out; 2150 if (!PageTransHuge(vmf->page)) 2151 goto out; 2152 old_page = vmf->page; 2153 } else { 2154 old_page = pmd_page(*vmf->pmd); 2155 page_remove_rmap(old_page, vmf->vma, true); 2156 pmdp_huge_clear_flush(vmf->vma, haddr, vmf->pmd); 2157 add_mm_counter(vmf->vma->vm_mm, MM_SHMEMPAGES, -HPAGE_PMD_NR); 2158 } 2159 2160 new_page = &vma_alloc_folio(gfp_flags, HPAGE_PMD_ORDER, 2161 vmf->vma, haddr, true)->page; 2162 if (!new_page) 2163 goto out; > 2164 copy_user_huge_page(new_page, old_page, haddr, vmf->vma, HPAGE_PMD_NR); 2165 __SetPageUptodate(new_page); 2166 2167 ret = do_set_pmd(vmf, new_page); 2168 2169 out: 2170 if (vmf->page) { 2171 unlock_page(vmf->page); 2172 put_page(vmf->page); 2173 } 2174 return ret; 2175 } 2176 -- 0-DAY CI Kernel Test Service https://01.org/lkp