aboutsummaryrefslogtreecommitdiffstats
path: root/include/linux/oom.h
blob: 2db9a1432511286d1b10d9185c935a89253371bc (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __INCLUDE_LINUX_OOM_H
#define __INCLUDE_LINUX_OOM_H


#include <linux/sched/signal.h>
#include <linux/types.h>
#include <linux/nodemask.h>
#include <uapi/linux/oom.h>
#include <linux/sched/coredump.h> /* MMF_* */
#include <linux/mm.h> /* VM_FAULT* */

struct zonelist;
struct notifier_block;
struct mem_cgroup;
struct task_struct;

enum oom_constraint {
	CONSTRAINT_NONE,
	CONSTRAINT_CPUSET,
	CONSTRAINT_MEMORY_POLICY,
	CONSTRAINT_MEMCG,
};

/*
 * Details of the page allocation that triggered the oom killer that are used to
 * determine what should be killed.
 */
struct oom_control {
	/* Used to determine cpuset */
	struct zonelist *zonelist;

	/* Used to determine mempolicy */
	nodemask_t *nodemask;

	/* Memory cgroup in which oom is invoked, or NULL for global oom */
	struct mem_cgroup *memcg;

	/* Used to determine cpuset and node locality requirement */
	const gfp_t gfp_mask;

	/*
	 * order == -1 means the oom kill is required by sysrq, otherwise only
	 * for display purposes.
	 */
	const int order;

	/* Used by oom implementation, do not set */
	unsigned long totalpages;
	struct task_struct *chosen;
	long chosen_points;

	/* Used to print the constraint info. */
	enum oom_constraint constraint;
};

extern struct mutex oom_lock;
extern struct mutex oom_adj_mutex;

static inline void set_current_oom_origin(void)
{
	current->signal->oom_flag_origin = true;
}

static inline void clear_current_oom_origin(void)
{
	current->signal->oom_flag_origin = false;
}

static inline bool oom_task_origin(const struct task_struct *p)
{
	return p->signal->oom_flag_origin;
}

static inline bool tsk_is_oom_victim(struct task_struct * tsk)
{
	return tsk->signal->oom_mm;
}

/*
 * Use this helper if tsk->mm != mm and the victim mm needs a special
 * handling. This is guaranteed to stay true after once set.
 */
static inline bool mm_is_oom_victim(struct mm_struct *mm)
{
	return test_bit(MMF_OOM_VICTIM, &mm->flags);
}

/*
 * Checks whether a page fault on the given mm is still reliable.
 * This is no longer true if the oom reaper started to reap the
 * address space which is reflected by MMF_UNSTABLE flag set in
 * the mm. At that moment any !shared mapping would lose the content
 * and could cause a memory corruption (zero pages instead of the
 * original content).
 *
 * User should call this before establishing a page table entry for
 * a !shared mapping and under the proper page table lock.
 *
 * Return 0 when the PF is safe VM_FAULT_SIGBUS otherwise.
 */
static inline vm_fault_t check_stable_address_space(struct mm_struct *mm)
{
	if (unlikely(test_bit(MMF_UNSTABLE, &mm->flags)))
		return VM_FAULT_SIGBUS;
	return 0;
}

bool __oom_reap_task_mm(struct mm_struct *mm);

long oom_badness(struct task_struct *p,
		unsigned long totalpages);

extern bool out_of_memory(struct oom_control *oc);

extern void exit_oom_victim(void);

extern int register_oom_notifier(struct notifier_block *nb);
extern int unregister_oom_notifier(struct notifier_block *nb);

extern bool oom_killer_disable(signed long timeout);
extern void oom_killer_enable(void);

extern struct task_struct *find_lock_task_mm(struct task_struct *p);

/* sysctls */
extern int sysctl_oom_dump_tasks;
extern int sysctl_oom_kill_allocating_task;
extern int sysctl_panic_on_oom;
#endif /* _INCLUDE_LINUX_OOM_H */