Hi Axel, Thank you for the patch! Yet something to improve: [auto build test ERROR on arm64/for-next/core] [also build test ERROR on powerpc/next s390/features tip/perf/core linus/master v5.11-rc3 next-20210115] [cannot apply to hp-parisc/for-next hnaz-linux-mm/master ia64/next sparc/master] [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] url: https://github.com/0day-ci/linux/commits/Axel-Rasmussen/userfaultfd-add-m... base: https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-next/core config: i386-randconfig-r013-20210115 (attached as .config) compiler: gcc-9 (Debian 9.3.0-15) 9.3.0 reproduce (this is a W=1 build): # https://github.com/0day-ci/linux/commit/97d3dcca13a550a56e5afe40abcc8db92... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Axel-Rasmussen/userfaultfd-add-minor-fault-handling/20210116-030900 git checkout 97d3dcca13a550a56e5afe40abcc8db929bd3916 # save the attached .config to linux build tree make W=1 ARCH=i386 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): In file included from include/linux/migrate.h:8, from fs/f2fs/data.c:3857: include/linux/hugetlb.h: In function 'want_pmd_share': 954 | if (uffd_disable_huge_pmd_share(vma)) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ cc1: some warnings being treated as errors -- In file included from mm/filemap.c:36: include/linux/hugetlb.h: In function 'want_pmd_share': 954 | if (uffd_disable_huge_pmd_share(vma)) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ mm/filemap.c: At top level: mm/filemap.c:830:14: warning: no previous prototype for '__add_to_page_cache_locked' [-Wmissing-prototypes] 830 | noinline int __add_to_page_cache_locked(struct page *page, | ^~~~~~~~~~~~~~~~~~~~~~~~~~ cc1: some warnings being treated as errors -- In file included from mm/util.c:16: include/linux/hugetlb.h: In function 'want_pmd_share': 954 | if (uffd_disable_huge_pmd_share(vma)) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ mm/util.c: In function 'page_mapping': mm/util.c:700:15: warning: variable 'entry' set but not used [-Wunused-but-set-variable] 700 | swp_entry_t entry; | ^~~~~ cc1: some warnings being treated as errors -- In file included from include/linux/migrate.h:8, from mm/page_alloc.c:61: include/linux/hugetlb.h: In function 'want_pmd_share': 954 | if (uffd_disable_huge_pmd_share(vma)) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ mm/page_alloc.c: At top level: mm/page_alloc.c:3594:15: warning: no previous prototype for 'should_fail_alloc_page' [-Wmissing-prototypes] 3594 | noinline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) | ^~~~~~~~~~~~~~~~~~~~~~ mm/page_alloc.c:6255:23: warning: no previous prototype for 'memmap_init' [-Wmissing-prototypes] 6255 | void __meminit __weak memmap_init(unsigned long size, int nid, | ^~~~~~~~~~~ cc1: some warnings being treated as errors -- In file included from kernel/events/core.c:31: include/linux/hugetlb.h: In function 'want_pmd_share': 954 | if (uffd_disable_huge_pmd_share(vma)) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ kernel/events/core.c: At top level: kernel/events/core.c:6535:6: warning: no previous prototype for 'perf_pmu_snapshot_aux' [-Wmissing-prototypes] 6535 | long perf_pmu_snapshot_aux(struct perf_buffer *rb, | ^~~~~~~~~~~~~~~~~~~~~ cc1: some warnings being treated as errors -- In file included from include/linux/migrate.h:8, from kernel/sched/sched.h:53, from kernel/sched/core.c:13: include/linux/hugetlb.h: In function 'want_pmd_share': 954 | if (uffd_disable_huge_pmd_share(vma)) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ kernel/sched/core.c: In function 'schedule_tail': kernel/sched/core.c:4238:13: warning: variable 'rq' set but not used [-Wunused-but-set-variable] 4238 | struct rq *rq; | ^~ cc1: some warnings being treated as errors -- In file included from include/linux/migrate.h:8, from kernel/sched/sched.h:53, from kernel/sched/rt.c:6: include/linux/hugetlb.h: In function 'want_pmd_share': 954 | if (uffd_disable_huge_pmd_share(vma)) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ kernel/sched/rt.c: At top level: kernel/sched/rt.c:669:6: warning: no previous prototype for 'sched_rt_bandwidth_account' [-Wmissing-prototypes] 669 | bool sched_rt_bandwidth_account(struct rt_rq *rt_rq) | ^~~~~~~~~~~~~~~~~~~~~~~~~~ cc1: some warnings being treated as errors vim +/uffd_disable_huge_pmd_share +954 include/linux/hugetlb.h 950 951 static inline bool want_pmd_share(struct vm_area_struct *vma) 952 { 953 #ifdef CONFIG_ARCH_WANT_HUGE_PMD_SHARE 955 return false; 956 return true; 957 #else 958 return false; 959 #endif 960 } 961 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org