1 #ifndef __INCLUDE_LINUX_OOM_H 2 #define __INCLUDE_LINUX_OOM_H 3 4 5 #include <linux/sched.h> 6 #include <linux/types.h> 7 #include <linux/nodemask.h> 8 #include <uapi/linux/oom.h> 9 10 struct zonelist; 11 struct notifier_block; 12 struct mem_cgroup; 13 struct task_struct; 14 15 /* 16 * Details of the page allocation that triggered the oom killer that are used to 17 * determine what should be killed. 18 */ 19 struct oom_control { 20 /* Used to determine cpuset */ 21 struct zonelist *zonelist; 22 23 /* Used to determine mempolicy */ 24 nodemask_t *nodemask; 25 26 /* Used to determine cpuset and node locality requirement */ 27 const gfp_t gfp_mask; 28 29 /* 30 * order == -1 means the oom kill is required by sysrq, otherwise only 31 * for display purposes. 32 */ 33 const int order; 34 }; 35 36 /* 37 * Types of limitations to the nodes from which allocations may occur 38 */ 39 enum oom_constraint { 40 CONSTRAINT_NONE, 41 CONSTRAINT_CPUSET, 42 CONSTRAINT_MEMORY_POLICY, 43 CONSTRAINT_MEMCG, 44 }; 45 46 enum oom_scan_t { 47 OOM_SCAN_OK, /* scan thread and find its badness */ 48 OOM_SCAN_CONTINUE, /* do not consider thread for oom kill */ 49 OOM_SCAN_ABORT, /* abort the iteration and return */ 50 OOM_SCAN_SELECT, /* always select this thread first */ 51 }; 52 53 /* Thread is the potential origin of an oom condition; kill first on oom */ 54 #define OOM_FLAG_ORIGIN ((__force oom_flags_t)0x1) 55 56 extern struct mutex oom_lock; 57 58 static inline void set_current_oom_origin(void) 59 { 60 current->signal->oom_flags |= OOM_FLAG_ORIGIN; 61 } 62 63 static inline void clear_current_oom_origin(void) 64 { 65 current->signal->oom_flags &= ~OOM_FLAG_ORIGIN; 66 } 67 68 static inline bool oom_task_origin(const struct task_struct *p) 69 { 70 return !!(p->signal->oom_flags & OOM_FLAG_ORIGIN); 71 } 72 73 extern void mark_oom_victim(struct task_struct *tsk); 74 75 #ifdef CONFIG_MMU 76 extern void try_oom_reaper(struct task_struct *tsk); 77 #else 78 static inline void try_oom_reaper(struct task_struct *tsk) 79 { 80 } 81 #endif 82 83 extern unsigned long oom_badness(struct task_struct *p, 84 struct mem_cgroup *memcg, const nodemask_t *nodemask, 85 unsigned long totalpages); 86 87 extern void oom_kill_process(struct oom_control *oc, struct task_struct *p, 88 unsigned int points, unsigned long totalpages, 89 struct mem_cgroup *memcg, const char *message); 90 91 extern void check_panic_on_oom(struct oom_control *oc, 92 enum oom_constraint constraint, 93 struct mem_cgroup *memcg); 94 95 extern enum oom_scan_t oom_scan_process_thread(struct oom_control *oc, 96 struct task_struct *task, unsigned long totalpages); 97 98 extern bool out_of_memory(struct oom_control *oc); 99 100 extern void exit_oom_victim(struct task_struct *tsk); 101 102 extern int register_oom_notifier(struct notifier_block *nb); 103 extern int unregister_oom_notifier(struct notifier_block *nb); 104 105 extern bool oom_killer_disabled; 106 extern bool oom_killer_disable(void); 107 extern void oom_killer_enable(void); 108 109 extern struct task_struct *find_lock_task_mm(struct task_struct *p); 110 111 static inline bool task_will_free_mem(struct task_struct *task) 112 { 113 struct signal_struct *sig = task->signal; 114 115 /* 116 * A coredumping process may sleep for an extended period in exit_mm(), 117 * so the oom killer cannot assume that the process will promptly exit 118 * and release memory. 119 */ 120 if (sig->flags & SIGNAL_GROUP_COREDUMP) 121 return false; 122 123 if (!(task->flags & PF_EXITING)) 124 return false; 125 126 /* Make sure that the whole thread group is going down */ 127 if (!thread_group_empty(task) && !(sig->flags & SIGNAL_GROUP_EXIT)) 128 return false; 129 130 return true; 131 } 132 133 /* sysctls */ 134 extern int sysctl_oom_dump_tasks; 135 extern int sysctl_oom_kill_allocating_task; 136 extern int sysctl_panic_on_oom; 137 #endif /* _INCLUDE_LINUX_OOM_H */ 138