xref: /linux-6.15/include/linux/oom.h (revision 4a8e43fe)
1 #ifndef __INCLUDE_LINUX_OOM_H
2 #define __INCLUDE_LINUX_OOM_H
3 
4 /*
5  * /proc/<pid>/oom_score_adj set to OOM_SCORE_ADJ_MIN disables oom killing for
6  * pid.
7  */
8 #define OOM_SCORE_ADJ_MIN	(-1000)
9 #define OOM_SCORE_ADJ_MAX	1000
10 
11 #ifdef __KERNEL__
12 
13 #include <linux/sched.h>
14 #include <linux/types.h>
15 #include <linux/nodemask.h>
16 
17 struct zonelist;
18 struct notifier_block;
19 struct mem_cgroup;
20 struct task_struct;
21 
22 /*
23  * Types of limitations to the nodes from which allocations may occur
24  */
25 enum oom_constraint {
26 	CONSTRAINT_NONE,
27 	CONSTRAINT_CPUSET,
28 	CONSTRAINT_MEMORY_POLICY,
29 	CONSTRAINT_MEMCG,
30 };
31 
32 enum oom_scan_t {
33 	OOM_SCAN_OK,		/* scan thread and find its badness */
34 	OOM_SCAN_CONTINUE,	/* do not consider thread for oom kill */
35 	OOM_SCAN_ABORT,		/* abort the iteration and return */
36 	OOM_SCAN_SELECT,	/* always select this thread first */
37 };
38 
39 extern void compare_swap_oom_score_adj(int old_val, int new_val);
40 extern int test_set_oom_score_adj(int new_val);
41 
42 extern unsigned long oom_badness(struct task_struct *p,
43 		struct mem_cgroup *memcg, const nodemask_t *nodemask,
44 		unsigned long totalpages);
45 extern void oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order,
46 			     unsigned int points, unsigned long totalpages,
47 			     struct mem_cgroup *memcg, nodemask_t *nodemask,
48 			     const char *message);
49 
50 extern int try_set_zonelist_oom(struct zonelist *zonelist, gfp_t gfp_flags);
51 extern void clear_zonelist_oom(struct zonelist *zonelist, gfp_t gfp_flags);
52 
53 extern void check_panic_on_oom(enum oom_constraint constraint, gfp_t gfp_mask,
54 			       int order, const nodemask_t *nodemask);
55 
56 extern enum oom_scan_t oom_scan_process_thread(struct task_struct *task,
57 		unsigned long totalpages, const nodemask_t *nodemask,
58 		bool force_kill);
59 extern void mem_cgroup_out_of_memory(struct mem_cgroup *memcg, gfp_t gfp_mask,
60 				     int order);
61 
62 extern void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask,
63 		int order, nodemask_t *mask, bool force_kill);
64 extern int register_oom_notifier(struct notifier_block *nb);
65 extern int unregister_oom_notifier(struct notifier_block *nb);
66 
67 extern bool oom_killer_disabled;
68 
69 static inline void oom_killer_disable(void)
70 {
71 	oom_killer_disabled = true;
72 }
73 
74 static inline void oom_killer_enable(void)
75 {
76 	oom_killer_disabled = false;
77 }
78 
79 extern struct task_struct *find_lock_task_mm(struct task_struct *p);
80 
81 /* sysctls */
82 extern int sysctl_oom_dump_tasks;
83 extern int sysctl_oom_kill_allocating_task;
84 extern int sysctl_panic_on_oom;
85 #endif /* __KERNEL__*/
86 #endif /* _INCLUDE_LINUX_OOM_H */
87