Hi Mina, Thank you for the patch! Yet something to improve: [auto build test ERROR on hnaz-mm/master] url: https://github.com/0day-ci/linux/commits/Mina-Almasry/mm-shmem-support-de... base: https://github.com/hnaz/linux-mm master config: um-i386_defconfig (attached as .config) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 reproduce (this is a W=1 build): # https://github.com/0day-ci/linux/commit/452a4d110272eb39892e4be30526411c7... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Mina-Almasry/mm-shmem-support-deterministic-charging-of-tmpfs/20211111-062122 git checkout 452a4d110272eb39892e4be30526411c7a5cb2e3 # save the attached .config to linux build tree mkdir build_dir make W=1 O=build_dir ARCH=um SUBARCH=i386 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 >>): mm/oom_kill.c: In function 'out_of_memory': 1116 | if (current->in_user_fault && | ^~ vim +1116 mm/oom_kill.c 1044 1045 /** 1046 * out_of_memory - kill the "best" process when we run out of memory 1047 * @oc: pointer to struct oom_control 1048 * 1049 * If we run out of memory, we have the choice between either 1050 * killing a random task (bad), letting the system crash (worse) 1051 * OR try to be smart about which process to kill. Note that we 1052 * don't have to be perfect here, we just have to be good. 1053 */ 1054 bool out_of_memory(struct oom_control *oc) 1055 { 1056 unsigned long freed = 0; 1057 1058 if (oom_killer_disabled) 1059 return false; 1060 1061 if (!is_memcg_oom(oc)) { 1062 blocking_notifier_call_chain(&oom_notify_list, 0, &freed); 1063 if (freed > 0) 1064 /* Got some memory back in the last second. */ 1065 return true; 1066 } 1067 1068 /* 1069 * If current has a pending SIGKILL or is exiting, then automatically 1070 * select it. The goal is to allow it to allocate so that it may 1071 * quickly exit and free its memory. 1072 */ 1073 if (task_will_free_mem(current)) { 1074 mark_oom_victim(current); 1075 wake_oom_reaper(current); 1076 return true; 1077 } 1078 1079 /* 1080 * The OOM killer does not compensate for IO-less reclaim. 1081 * pagefault_out_of_memory lost its gfp context so we have to 1082 * make sure exclude 0 mask - all other users should have at least 1083 * ___GFP_DIRECT_RECLAIM to get here. But mem_cgroup_oom() has to 1084 * invoke the OOM killer even if it is a GFP_NOFS allocation. 1085 */ 1086 if (oc->gfp_mask && !(oc->gfp_mask & __GFP_FS) && !is_memcg_oom(oc)) 1087 return true; 1088 1089 /* 1090 * Check if there were limitations on the allocation (only relevant for 1091 * NUMA and memcg) that may require different handling. 1092 */ 1093 oc->constraint = constrained_alloc(oc); 1094 if (oc->constraint != CONSTRAINT_MEMORY_POLICY) 1095 oc->nodemask = NULL; 1096 check_panic_on_oom(oc); 1097 1098 if (!is_memcg_oom(oc) && sysctl_oom_kill_allocating_task && 1099 current->mm && !oom_unkillable_task(current) && 1100 oom_cpuset_eligible(current, oc) && 1101 current->signal->oom_score_adj != OOM_SCORE_ADJ_MIN) { 1102 get_task_struct(current); 1103 oc->chosen = current; 1104 oom_kill_process(oc, "Out of memory (oom_kill_allocating_task)"); 1105 return true; 1106 } 1107 1108 select_bad_process(oc); 1109 /* Found nothing?!?! */ 1110 if (!oc->chosen) { 1111 if (is_remote_oom(oc->memcg)) { 1112 /* 1113 * For remote ooms in userfaults, we have no choice but 1114 * to kill the allocating process. 1115 */ 1117 !oom_unkillable_task(current)) { 1118 get_task_struct(current); 1119 oc->chosen = current; 1120 oom_kill_process( 1121 oc, 1122 "Out of memory (Killing remote allocating task)"); 1123 return true; 1124 } 1125 1126 /* 1127 * For remote ooms in non-userfaults, simply return 1128 * ENOMEM to the caller. 1129 */ 1130 return false; 1131 } 1132 1133 dump_header(oc, NULL); 1134 pr_warn("Out of memory and no killable processes...\n"); 1135 /* 1136 * If we got here due to an actual allocation at the 1137 * system level, we cannot survive this and will enter 1138 * an endless loop in the allocator. Bail out now. 1139 */ 1140 if (!is_sysrq_oom(oc) && !is_memcg_oom(oc)) 1141 panic("System is deadlocked on memory\n"); 1142 } 1143 if (oc->chosen && oc->chosen != (void *)-1UL) 1144 oom_kill_process(oc, !is_memcg_oom(oc) ? "Out of memory" : 1145 "Memory cgroup out of memory"); 1146 return !!oc->chosen; 1147 } 1148 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org