1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __INCLUDE_LINUX_OOM_H
3 #define __INCLUDE_LINUX_OOM_H
4
5
6 #include <linux/sched/signal.h>
7 #include <linux/types.h>
8 #include <linux/nodemask.h>
9 #include <uapi/linux/oom.h>
10 #include <linux/sched/coredump.h> /* MMF_* */
11 #include <linux/mm.h> /* VM_FAULT* */
12
13 struct zonelist;
14 struct notifier_block;
15 struct mem_cgroup;
16 struct task_struct;
17
18 enum oom_constraint {
19 CONSTRAINT_NONE,
20 CONSTRAINT_CPUSET,
21 CONSTRAINT_MEMORY_POLICY,
22 CONSTRAINT_MEMCG,
23 };
24
25 /*
26 * Details of the page allocation that triggered the oom killer that are used to
27 * determine what should be killed.
28 */
29 struct oom_control {
30 /* Used to determine cpuset */
31 struct zonelist *zonelist;
32
33 /* Used to determine mempolicy */
34 nodemask_t *nodemask;
35
36 /* Memory cgroup in which oom is invoked, or NULL for global oom */
37 struct mem_cgroup *memcg;
38
39 /* Used to determine cpuset and node locality requirement */
40 const gfp_t gfp_mask;
41
42 /*
43 * order == -1 means the oom kill is required by sysrq, otherwise only
44 * for display purposes.
45 */
46 const int order;
47
48 /* Used by oom implementation, do not set */
49 unsigned long totalpages;
50 struct task_struct *chosen;
51 long chosen_points;
52 struct task_struct *chosen_non_negative_adj;
53 long chosen_non_negative_adj_points;
54
55 /* Used to print the constraint info. */
56 enum oom_constraint constraint;
57 };
58
59 extern struct mutex oom_lock;
60 extern struct mutex oom_adj_mutex;
61
set_current_oom_origin(void)62 static inline void set_current_oom_origin(void)
63 {
64 current->signal->oom_flag_origin = true;
65 }
66
clear_current_oom_origin(void)67 static inline void clear_current_oom_origin(void)
68 {
69 current->signal->oom_flag_origin = false;
70 }
71
oom_task_origin(const struct task_struct * p)72 static inline bool oom_task_origin(const struct task_struct *p)
73 {
74 return p->signal->oom_flag_origin;
75 }
76
tsk_is_oom_victim(struct task_struct * tsk)77 static inline bool tsk_is_oom_victim(struct task_struct * tsk)
78 {
79 return tsk->signal->oom_mm;
80 }
81
82 /*
83 * Use this helper if tsk->mm != mm and the victim mm needs a special
84 * handling. This is guaranteed to stay true after once set.
85 */
mm_is_oom_victim(struct mm_struct * mm)86 static inline bool mm_is_oom_victim(struct mm_struct *mm)
87 {
88 return test_bit(MMF_OOM_VICTIM, &mm->flags);
89 }
90
91 /*
92 * Checks whether a page fault on the given mm is still reliable.
93 * This is no longer true if the oom reaper started to reap the
94 * address space which is reflected by MMF_UNSTABLE flag set in
95 * the mm. At that moment any !shared mapping would lose the content
96 * and could cause a memory corruption (zero pages instead of the
97 * original content).
98 *
99 * User should call this before establishing a page table entry for
100 * a !shared mapping and under the proper page table lock.
101 *
102 * Return 0 when the PF is safe VM_FAULT_SIGBUS otherwise.
103 */
check_stable_address_space(struct mm_struct * mm)104 static inline vm_fault_t check_stable_address_space(struct mm_struct *mm)
105 {
106 if (unlikely(test_bit(MMF_UNSTABLE, &mm->flags)))
107 return VM_FAULT_SIGBUS;
108 return 0;
109 }
110
111 bool __oom_reap_task_mm(struct mm_struct *mm);
112
113 long oom_badness(struct task_struct *p,
114 unsigned long totalpages);
115
116 extern bool out_of_memory(struct oom_control *oc);
117
118 extern void exit_oom_victim(void);
119
120 extern int register_oom_notifier(struct notifier_block *nb);
121 extern int unregister_oom_notifier(struct notifier_block *nb);
122
123 extern bool oom_killer_disable(signed long timeout);
124 extern void oom_killer_enable(void);
125
126 extern struct task_struct *find_lock_task_mm(struct task_struct *p);
127
128 /* sysctls */
129 extern int sysctl_oom_dump_tasks;
130 extern int sysctl_oom_kill_allocating_task;
131 extern int sysctl_panic_on_oom;
132
133 /* call for adding killed process to reaper. */
134 extern void add_to_oom_reaper(struct task_struct *p);
135 #endif /* _INCLUDE_LINUX_OOM_H */
136