Hi Toshiki, Thank you for the patch! Yet something to improve: [auto build test ERROR on linus/master] [cannot apply to v5.4-rc6 next-20191108] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system. BTW, we also suggest to use '--base' option to specify the base tree in git format-patch, please see https://stackoverflow.com/a/37406982] url: https://github.com/0day-ci/linux/commits/Toshiki-Fukasawa/make-pfn-walker-support-ZONE_DEVICE/20191110-000508 base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 0058b0a506e40d9a2c62015fe92eb64a44d78cd9 config: i386-randconfig-b002-201945 (attached as .config) compiler: gcc-7 (Debian 7.4.0-14) 7.4.0 reproduce: # save the attached .config to linux build tree make ARCH=i386 If you fix the issue, kindly add following tag Reported-by: kbuild test robot All errors (new ones prefixed by >>): fs/proc/page.c: In function 'kpage_common_read': >> fs/proc/page.c:46:17: error: implicit declaration of function 'pfn_zone_device'; did you mean 'pgprot_device'? [-Werror=implicit-function-declaration] if (!ppage && pfn_zone_device(pfn)) { ^~~~~~~~~~~~~~~ pgprot_device Cyclomatic Complexity 5 include/linux/compiler.h:__read_once_size Cyclomatic Complexity 1 include/linux/kasan-checks.h:kasan_check_read Cyclomatic Complexity 1 arch/x86/include/asm/bitops.h:constant_test_bit Cyclomatic Complexity 1 arch/x86/include/asm/bitops.h:variable_test_bit Cyclomatic Complexity 1 arch/x86/include/asm/atomic.h:arch_atomic_read Cyclomatic Complexity 1 include/asm-generic/atomic-instrumented.h:atomic_read Cyclomatic Complexity 1 include/linux/page-flags.h:PageTail Cyclomatic Complexity 3 include/linux/page-flags.h:PageCompound Cyclomatic Complexity 1 include/linux/page-flags.h:PageLRU Cyclomatic Complexity 1 include/linux/page-flags.h:PageSlab Cyclomatic Complexity 1 include/linux/page-flags.h:PageSwapCache Cyclomatic Complexity 1 include/linux/page-flags.h:PageAnon Cyclomatic Complexity 1 include/linux/page-flags.h:PageKsm Cyclomatic Complexity 1 include/linux/page-flags.h:PageHead Cyclomatic Complexity 1 include/linux/page-flags.h:PageTransCompound Cyclomatic Complexity 1 include/linux/page-flags.h:page_has_type Cyclomatic Complexity 1 include/linux/page-flags.h:PageBuddy Cyclomatic Complexity 1 include/linux/page-flags.h:PageOffline Cyclomatic Complexity 1 include/linux/page-flags.h:PageTable Cyclomatic Complexity 1 include/linux/memremap.h:nr_valid_pages_zone_device Cyclomatic Complexity 1 include/linux/sched.h:_cond_resched Cyclomatic Complexity 1 include/asm-generic/pgtable.h:is_zero_pfn Cyclomatic Complexity 1 include/linux/huge_mm.h:is_huge_zero_page Cyclomatic Complexity 1 fs/proc/page.c:kpf_copy_bit Cyclomatic Complexity 2 include/asm-generic/bitops-instrumented.h:test_bit Cyclomatic Complexity 2 include/linux/page_idle.h:page_is_idle Cyclomatic Complexity 2 include/linux/page-flags.h:compound_head Cyclomatic Complexity 1 include/linux/page_ref.h:page_count Cyclomatic Complexity 1 fs/proc/page.c:proc_page_init Cyclomatic Complexity 12 fs/proc/page.c:kpage_common_read Cyclomatic Complexity 1 fs/proc/page.c:kpageflags_read Cyclomatic Complexity 1 fs/proc/page.c:kpagecount_read Cyclomatic Complexity 2 include/linux/mm.h:page_mapcount Cyclomatic Complexity 4 fs/proc/page.c:page_count_data Cyclomatic Complexity 23 fs/proc/page.c:stable_page_flags Cyclomatic Complexity 1 fs/proc/page.c:page_flags_data cc1: some warnings being treated as errors vim +46 fs/proc/page.c 25 26 /* 27 * This is general function to read various data on pages. 28 */ 29 static ssize_t kpage_common_read(struct file *file, char __user *buf, 30 size_t count, loff_t *ppos, read_page_data_fn_t read_fn) 31 { 32 u64 __user *out = (u64 __user *)buf; 33 struct page *ppage; 34 unsigned long src = *ppos; 35 unsigned long pfn; 36 unsigned long valid_pages = 0; 37 ssize_t ret = 0; 38 39 pfn = src / KPMSIZE; 40 count = min_t(size_t, count, (max_pfn * KPMSIZE) - src); 41 if (src & KPMMASK || count & KPMMASK) 42 return -EINVAL; 43 44 while (count > 0) { 45 ppage = pfn_to_online_page(pfn); > 46 if (!ppage && pfn_zone_device(pfn)) { 47 /* 48 * Skip to read first few uninitialized pages on 49 * ZONE_DEVICE. And count valid pages starting 50 * with the pfn so that minimize the number of 51 * calls to nr_valid_pages_zone_device(). 52 */ 53 if (!valid_pages) 54 valid_pages = nr_valid_pages_zone_device(pfn); 55 if (valid_pages) { 56 ppage = pfn_to_page(pfn); 57 valid_pages--; 58 } 59 } else if (valid_pages) { 60 /* ZONE_DEVICE has been hot removed */ 61 valid_pages = 0; 62 } 63 64 if (put_user(read_fn(ppage), out)) { 65 ret = -EFAULT; 66 break; 67 } 68 69 pfn++; 70 out++; 71 count -= KPMSIZE; 72 73 cond_resched(); 74 } 75 76 *ppos += (char __user *)out - buf; 77 if (!ret) 78 ret = (char __user *)out - buf; 79 return ret; 80 } 81 --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org Intel Corporation