include/linux/oom.h

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