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
set_current_oom_origin(void)58 static inline void set_current_oom_origin(void)
59 {
60 current->signal->oom_flags |= OOM_FLAG_ORIGIN;
61 }
62
clear_current_oom_origin(void)63 static inline void clear_current_oom_origin(void)
64 {
65 current->signal->oom_flags &= ~OOM_FLAG_ORIGIN;
66 }
67
oom_task_origin(const struct task_struct * p)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 extern unsigned long oom_badness(struct task_struct *p,
76 struct mem_cgroup *memcg, const nodemask_t *nodemask,
77 unsigned long totalpages);
78
79 extern int oom_kills_count(void);
80 extern void note_oom_kill(void);
81 extern void oom_kill_process(struct oom_control *oc, struct task_struct *p,
82 unsigned int points, unsigned long totalpages,
83 struct mem_cgroup *memcg, const char *message);
84
85 extern void check_panic_on_oom(struct oom_control *oc,
86 enum oom_constraint constraint,
87 struct mem_cgroup *memcg);
88
89 extern enum oom_scan_t oom_scan_process_thread(struct oom_control *oc,
90 struct task_struct *task, unsigned long totalpages);
91
92 extern bool out_of_memory(struct oom_control *oc);
93
94 extern void exit_oom_victim(void);
95
96 extern int register_oom_notifier(struct notifier_block *nb);
97 extern int unregister_oom_notifier(struct notifier_block *nb);
98
99 extern bool oom_killer_disabled;
100 extern bool oom_killer_disable(void);
101 extern void oom_killer_enable(void);
102
103 extern struct task_struct *find_lock_task_mm(struct task_struct *p);
104
task_will_free_mem(struct task_struct * task)105 static inline bool task_will_free_mem(struct task_struct *task)
106 {
107 /*
108 * A coredumping process may sleep for an extended period in exit_mm(),
109 * so the oom killer cannot assume that the process will promptly exit
110 * and release memory.
111 */
112 return (task->flags & PF_EXITING) &&
113 !(task->signal->flags & SIGNAL_GROUP_COREDUMP);
114 }
115
116 /* sysctls */
117 extern int sysctl_oom_dump_tasks;
118 extern int sysctl_oom_kill_allocating_task;
119 extern int sysctl_panic_on_oom;
120 #endif /* _INCLUDE_LINUX_OOM_H */
121