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 | |
53 | /* Used to print the constraint info. */ |
54 | enum oom_constraint constraint; |
55 | }; |
56 | |
57 | extern struct mutex oom_lock; |
58 | extern struct mutex oom_adj_mutex; |
59 | |
60 | static inline void set_current_oom_origin(void) |
61 | { |
62 | current->signal->oom_flag_origin = true; |
63 | } |
64 | |
65 | static inline void clear_current_oom_origin(void) |
66 | { |
67 | current->signal->oom_flag_origin = false; |
68 | } |
69 | |
70 | static inline bool oom_task_origin(const struct task_struct *p) |
71 | { |
72 | return p->signal->oom_flag_origin; |
73 | } |
74 | |
75 | static inline bool tsk_is_oom_victim(struct task_struct * tsk) |
76 | { |
77 | return tsk->signal->oom_mm; |
78 | } |
79 | |
80 | /* |
81 | * Use this helper if tsk->mm != mm and the victim mm needs a special |
82 | * handling. This is guaranteed to stay true after once set. |
83 | */ |
84 | static inline bool mm_is_oom_victim(struct mm_struct *mm) |
85 | { |
86 | return test_bit(MMF_OOM_VICTIM, &mm->flags); |
87 | } |
88 | |
89 | /* |
90 | * Checks whether a page fault on the given mm is still reliable. |
91 | * This is no longer true if the oom reaper started to reap the |
92 | * address space which is reflected by MMF_UNSTABLE flag set in |
93 | * the mm. At that moment any !shared mapping would lose the content |
94 | * and could cause a memory corruption (zero pages instead of the |
95 | * original content). |
96 | * |
97 | * User should call this before establishing a page table entry for |
98 | * a !shared mapping and under the proper page table lock. |
99 | * |
100 | * Return 0 when the PF is safe VM_FAULT_SIGBUS otherwise. |
101 | */ |
102 | static inline vm_fault_t check_stable_address_space(struct mm_struct *mm) |
103 | { |
104 | if (unlikely(test_bit(MMF_UNSTABLE, &mm->flags))) |
105 | return VM_FAULT_SIGBUS; |
106 | return 0; |
107 | } |
108 | |
109 | bool __oom_reap_task_mm(struct mm_struct *mm); |
110 | |
111 | long oom_badness(struct task_struct *p, |
112 | unsigned long totalpages); |
113 | |
114 | extern bool out_of_memory(struct oom_control *oc); |
115 | |
116 | extern void exit_oom_victim(void); |
117 | |
118 | extern int register_oom_notifier(struct notifier_block *nb); |
119 | extern int unregister_oom_notifier(struct notifier_block *nb); |
120 | |
121 | extern bool oom_killer_disable(signed long timeout); |
122 | extern void oom_killer_enable(void); |
123 | |
124 | extern struct task_struct *find_lock_task_mm(struct task_struct *p); |
125 | |
126 | #endif /* _INCLUDE_LINUX_OOM_H */ |
127 | |