tree: https://chromium.googlesource.com/chromiumos/third_party/kernel chromeos-5.15 head: b4852fbf90916fdc2f1e0e282e100f7e0e889d77 commit: 467d55003e7cac35a55032ae02df445c18566434 [989/2818] CHROMIUM: mm: move low memory code config: arm-chromiumos-arm-customedconfig-chrome-os:chromeos-5.15:b4852fbf90916fdc2f1e0e282e100f7e0e889d77 (https://download.01.org/0day-ci/archive/20211212/202112120914.wBfKM0Ox-lk...) compiler: arm-linux-gnueabi-gcc (GCC) 11.2.0 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 git remote add chrome-os https://chromium.googlesource.com/chromiumos/third_party/kernel git fetch --no-tags chrome-os chromeos-5.15 git checkout 467d55003e7cac35a55032ae02df445c18566434 # save the config file to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=arm SHELL=/bin/bash 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 >>): 53 | void low_mem_notify(void) | ^~~~~~~~~~~~~~ 121 | bool low_mem_check(void) | ^~~~~~~~~~~~~ cc1: all warnings being treated as errors vim +/low_mem_notify +53 mm/low-mem-notify.c 6f9d293215315a Luigi Semenzato 2014-04-03 52 6f9d293215315a Luigi Semenzato 2014-04-03 @53 void low_mem_notify(void) 6f9d293215315a Luigi Semenzato 2014-04-03 54 { 6f9d293215315a Luigi Semenzato 2014-04-03 55 atomic_set(&low_mem_state, true); 6f9d293215315a Luigi Semenzato 2014-04-03 56 wake_up(&low_mem_wait); 6f9d293215315a Luigi Semenzato 2014-04-03 57 } 6f9d293215315a Luigi Semenzato 2014-04-03 58 467d55003e7cac Yu Zhao 2019-11-10 59 /* 467d55003e7cac Yu Zhao 2019-11-10 60 * Compute available memory used by files that can be reclaimed quickly. 467d55003e7cac Yu Zhao 2019-11-10 61 */ 467d55003e7cac Yu Zhao 2019-11-10 62 static unsigned long get_available_file_mem(void) 6f9d293215315a Luigi Semenzato 2014-04-03 63 { 467d55003e7cac Yu Zhao 2019-11-10 64 unsigned long file_mem = 467d55003e7cac Yu Zhao 2019-11-10 65 global_node_page_state(NR_ACTIVE_FILE) + 467d55003e7cac Yu Zhao 2019-11-10 66 global_node_page_state(NR_INACTIVE_FILE); 467d55003e7cac Yu Zhao 2019-11-10 67 unsigned long dirty_mem = global_node_page_state(NR_FILE_DIRTY); 467d55003e7cac Yu Zhao 2019-11-10 68 unsigned long min_file_mem = min_filelist_kbytes >> (PAGE_SHIFT - 10); 467d55003e7cac Yu Zhao 2019-11-10 69 unsigned long clean_file_mem = file_mem > dirty_mem ? 467d55003e7cac Yu Zhao 2019-11-10 70 file_mem - dirty_mem : 0; 467d55003e7cac Yu Zhao 2019-11-10 71 /* Conservatively estimate the amount of available_file_mem */ 467d55003e7cac Yu Zhao 2019-11-10 72 unsigned long available_file_mem = clean_file_mem > min_file_mem ? 467d55003e7cac Yu Zhao 2019-11-10 73 clean_file_mem - min_file_mem : 0; 467d55003e7cac Yu Zhao 2019-11-10 74 return available_file_mem; 467d55003e7cac Yu Zhao 2019-11-10 75 } 6f9d293215315a Luigi Semenzato 2014-04-03 76 467d55003e7cac Yu Zhao 2019-11-10 77 /* 467d55003e7cac Yu Zhao 2019-11-10 78 * Available anonymous memory. 467d55003e7cac Yu Zhao 2019-11-10 79 */ 467d55003e7cac Yu Zhao 2019-11-10 80 static unsigned long get_available_anon_mem(void) 467d55003e7cac Yu Zhao 2019-11-10 81 { 467d55003e7cac Yu Zhao 2019-11-10 82 return global_node_page_state(NR_ACTIVE_ANON) + 467d55003e7cac Yu Zhao 2019-11-10 83 global_node_page_state(NR_INACTIVE_ANON); 6f9d293215315a Luigi Semenzato 2014-04-03 84 } 6f9d293215315a Luigi Semenzato 2014-04-03 85 467d55003e7cac Yu Zhao 2019-11-10 86 /* 467d55003e7cac Yu Zhao 2019-11-10 87 * Compute "available" memory, that is either free memory or memory that can be 467d55003e7cac Yu Zhao 2019-11-10 88 * reclaimed quickly, adjusted for the presence of swap. 467d55003e7cac Yu Zhao 2019-11-10 89 */ 467d55003e7cac Yu Zhao 2019-11-10 90 static unsigned long get_available_mem_adj(void) 467d55003e7cac Yu Zhao 2019-11-10 91 { 467d55003e7cac Yu Zhao 2019-11-10 92 /* free_mem is completely unallocated; clean file-backed memory 467d55003e7cac Yu Zhao 2019-11-10 93 * (file_mem - dirty_mem) is easy to reclaim, except for the last 467d55003e7cac Yu Zhao 2019-11-10 94 * min_filelist_kbytes. totalreserve_pages is the reserve of pages that 467d55003e7cac Yu Zhao 2019-11-10 95 * are not available to user space. 467d55003e7cac Yu Zhao 2019-11-10 96 */ 467d55003e7cac Yu Zhao 2019-11-10 97 unsigned long raw_free_mem = global_zone_page_state(NR_FREE_PAGES); 467d55003e7cac Yu Zhao 2019-11-10 98 unsigned long free_mem = raw_free_mem > totalreserve_pages ? 467d55003e7cac Yu Zhao 2019-11-10 99 raw_free_mem - totalreserve_pages : 0; 467d55003e7cac Yu Zhao 2019-11-10 100 unsigned long available_mem = free_mem + get_available_file_mem(); 467d55003e7cac Yu Zhao 2019-11-10 101 unsigned long swappable_pages = min_t(unsigned long, 467d55003e7cac Yu Zhao 2019-11-10 102 get_nr_swap_pages(), get_available_anon_mem()); 467d55003e7cac Yu Zhao 2019-11-10 103 /* 467d55003e7cac Yu Zhao 2019-11-10 104 * The contribution of swap is reduced by a factor of 467d55003e7cac Yu Zhao 2019-11-10 105 * low_mem_ram_vs_swap_weight. 467d55003e7cac Yu Zhao 2019-11-10 106 */ 467d55003e7cac Yu Zhao 2019-11-10 107 return available_mem + swappable_pages / low_mem_ram_vs_swap_weight; 467d55003e7cac Yu Zhao 2019-11-10 108 } 467d55003e7cac Yu Zhao 2019-11-10 109 467d55003e7cac Yu Zhao 2019-11-10 110 #ifdef CONFIG_SYSFS 467d55003e7cac Yu Zhao 2019-11-10 111 static void low_mem_threshold_notify(void); 467d55003e7cac Yu Zhao 2019-11-10 112 #else 467d55003e7cac Yu Zhao 2019-11-10 113 static void low_mem_threshold_notify(void) 467d55003e7cac Yu Zhao 2019-11-10 114 { 467d55003e7cac Yu Zhao 2019-11-10 115 } 467d55003e7cac Yu Zhao 2019-11-10 116 #endif 467d55003e7cac Yu Zhao 2019-11-10 117 467d55003e7cac Yu Zhao 2019-11-10 118 /* 467d55003e7cac Yu Zhao 2019-11-10 119 * Returns TRUE if we are in a low memory state. 467d55003e7cac Yu Zhao 2019-11-10 120 */ 467d55003e7cac Yu Zhao 2019-11-10 @121 bool low_mem_check(void) 467d55003e7cac Yu Zhao 2019-11-10 122 { 467d55003e7cac Yu Zhao 2019-11-10 123 static bool was_low_mem; /* = false, as per style guide */ 467d55003e7cac Yu Zhao 2019-11-10 124 static atomic_t in_low_mem_check = ATOMIC_INIT(0); 467d55003e7cac Yu Zhao 2019-11-10 125 /* last observed threshold */ 467d55003e7cac Yu Zhao 2019-11-10 126 static unsigned int low_mem_threshold_last = UINT_MAX; 467d55003e7cac Yu Zhao 2019-11-10 127 /* Limit logging low memory to once per second. */ 467d55003e7cac Yu Zhao 2019-11-10 128 static DEFINE_RATELIMIT_STATE(low_mem_logging_ratelimit, 1 * HZ, 1); 467d55003e7cac Yu Zhao 2019-11-10 129 467d55003e7cac Yu Zhao 2019-11-10 130 /* We declare a low-memory condition when a combination of RAM and swap 467d55003e7cac Yu Zhao 2019-11-10 131 * space is low. 467d55003e7cac Yu Zhao 2019-11-10 132 */ 467d55003e7cac Yu Zhao 2019-11-10 133 unsigned long available_mem = get_available_mem_adj(); 467d55003e7cac Yu Zhao 2019-11-10 134 /* 467d55003e7cac Yu Zhao 2019-11-10 135 * For backwards compatibility with the older margin interface, we will 467d55003e7cac Yu Zhao 2019-11-10 136 * trigger the /dev/chromeos-low_mem device when we are below the 467d55003e7cac Yu Zhao 2019-11-10 137 * lowest threshold 467d55003e7cac Yu Zhao 2019-11-10 138 */ 467d55003e7cac Yu Zhao 2019-11-10 139 bool is_low_mem = available_mem < low_mem_thresholds[0]; 467d55003e7cac Yu Zhao 2019-11-10 140 unsigned int threshold_lowest = UINT_MAX; 467d55003e7cac Yu Zhao 2019-11-10 141 int i; 467d55003e7cac Yu Zhao 2019-11-10 142 467d55003e7cac Yu Zhao 2019-11-10 143 if (!low_mem_margin_enabled) 467d55003e7cac Yu Zhao 2019-11-10 144 return false; 467d55003e7cac Yu Zhao 2019-11-10 145 467d55003e7cac Yu Zhao 2019-11-10 146 if (atomic_read(&in_low_mem_check) || atomic_xchg(&in_low_mem_check, 1)) 467d55003e7cac Yu Zhao 2019-11-10 147 return was_low_mem; 467d55003e7cac Yu Zhao 2019-11-10 148 467d55003e7cac Yu Zhao 2019-11-10 149 if (unlikely(is_low_mem && !was_low_mem) && 467d55003e7cac Yu Zhao 2019-11-10 150 __ratelimit(&low_mem_logging_ratelimit)) { 467d55003e7cac Yu Zhao 2019-11-10 151 pr_info("entering low_mem (avail RAM = %lu kB, avail swap %lu kB, avail file %lu kB, anon mem: %lu kB)\n", 467d55003e7cac Yu Zhao 2019-11-10 152 available_mem * PAGE_SIZE / 1024, 467d55003e7cac Yu Zhao 2019-11-10 153 get_nr_swap_pages() * PAGE_SIZE / 1024, 467d55003e7cac Yu Zhao 2019-11-10 154 get_available_file_mem() * PAGE_SIZE / 1024, 467d55003e7cac Yu Zhao 2019-11-10 155 get_available_anon_mem() * PAGE_SIZE / 1024); 467d55003e7cac Yu Zhao 2019-11-10 156 } 467d55003e7cac Yu Zhao 2019-11-10 157 was_low_mem = is_low_mem; 467d55003e7cac Yu Zhao 2019-11-10 158 467d55003e7cac Yu Zhao 2019-11-10 159 if (is_low_mem) 467d55003e7cac Yu Zhao 2019-11-10 160 low_mem_notify(); 467d55003e7cac Yu Zhao 2019-11-10 161 467d55003e7cac Yu Zhao 2019-11-10 162 for (i = 0; i < low_mem_threshold_count; i++) { 467d55003e7cac Yu Zhao 2019-11-10 163 if (available_mem < low_mem_thresholds[i]) { 467d55003e7cac Yu Zhao 2019-11-10 164 threshold_lowest = i; 467d55003e7cac Yu Zhao 2019-11-10 165 break; 467d55003e7cac Yu Zhao 2019-11-10 166 } 467d55003e7cac Yu Zhao 2019-11-10 167 } 467d55003e7cac Yu Zhao 2019-11-10 168 467d55003e7cac Yu Zhao 2019-11-10 169 /* we crossed one or more thresholds */ 467d55003e7cac Yu Zhao 2019-11-10 170 if (unlikely(threshold_lowest < low_mem_threshold_last)) 467d55003e7cac Yu Zhao 2019-11-10 171 low_mem_threshold_notify(); 467d55003e7cac Yu Zhao 2019-11-10 172 467d55003e7cac Yu Zhao 2019-11-10 173 low_mem_threshold_last = threshold_lowest; 467d55003e7cac Yu Zhao 2019-11-10 174 467d55003e7cac Yu Zhao 2019-11-10 175 atomic_set(&in_low_mem_check, 0); 467d55003e7cac Yu Zhao 2019-11-10 176 467d55003e7cac Yu Zhao 2019-11-10 177 return is_low_mem; 467d55003e7cac Yu Zhao 2019-11-10 178 } 467d55003e7cac Yu Zhao 2019-11-10 179 :::::: The code at line 53 was first introduced by commit :::::: 6f9d293215315aefb091456a2eb8c2799ff1232a CHROMIUM: Add /dev/low-mem device for low-memory notification. :::::: TO: Luigi Semenzato <semenzato(a)chromium.org&gt; :::::: CC: Guenter Roeck <groeck(a)chromium.org&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org