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  * Types of limitations to the nodes from which allocations may occur
  17  */
  18 enum oom_constraint {
  19         CONSTRAINT_NONE,
  20         CONSTRAINT_CPUSET,
  21         CONSTRAINT_MEMORY_POLICY,
  22         CONSTRAINT_MEMCG,
  23 };
  24
  25 enum oom_scan_t {
  26         OOM_SCAN_OK,            /* scan thread and find its badness */
  27         OOM_SCAN_CONTINUE,      /* do not consider thread for oom kill */
  28         OOM_SCAN_ABORT,         /* abort the iteration and return */
  29         OOM_SCAN_SELECT,        /* always select this thread first */
  30 };
  31
  32 /* Thread is the potential origin of an oom condition; kill first on oom */
  33 #define OOM_FLAG_ORIGIN         ((__force oom_flags_t)0x1)
  34
  35 static inline void set_current_oom_origin(void)
  36 {
  37         current->signal->oom_flags |= OOM_FLAG_ORIGIN;
  38 }
  39
  40 static inline void clear_current_oom_origin(void)
  41 {
  42         current->signal->oom_flags &= ~OOM_FLAG_ORIGIN;
  43 }
  44
  45 static inline bool oom_task_origin(const struct task_struct *p)
  46 {
  47         return !!(p->signal->oom_flags & OOM_FLAG_ORIGIN);
  48 }
  49
  50 extern unsigned long oom_badness(struct task_struct *p,
  51                 struct mem_cgroup *memcg, const nodemask_t *nodemask,
  52                 unsigned long totalpages);
  53
  54 extern int oom_kills_count(void);
  55 extern void note_oom_kill(void);
  56 extern void oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order,
  57                              unsigned int points, unsigned long totalpages,
  58                              struct mem_cgroup *memcg, nodemask_t *nodemask,
  59                              const char *message);
  60
  61 extern bool oom_zonelist_trylock(struct zonelist *zonelist, gfp_t gfp_flags);
  62 extern void oom_zonelist_unlock(struct zonelist *zonelist, gfp_t gfp_flags);
  63
  64 extern void check_panic_on_oom(enum oom_constraint constraint, gfp_t gfp_mask,
  65                                int order, const nodemask_t *nodemask);
  66
  67 extern enum oom_scan_t oom_scan_process_thread(struct task_struct *task,
  68                 unsigned long totalpages, const nodemask_t *nodemask,
  69                 bool force_kill);
  70
  71 extern void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask,
  72                 int order, nodemask_t *mask, bool force_kill);
  73 extern int register_oom_notifier(struct notifier_block *nb);
  74 extern int unregister_oom_notifier(struct notifier_block *nb);
  75
  76 extern bool oom_killer_disabled;
  77
  78 static inline void oom_killer_disable(void)
  79 {
  80         oom_killer_disabled = true;
  81 }
  82
  83 static inline void oom_killer_enable(void)
  84 {
  85         oom_killer_disabled = false;
  86 }
  87
  88 extern struct task_struct *find_lock_task_mm(struct task_struct *p);
  89
  90 static inline bool task_will_free_mem(struct task_struct *task)
  91 {
  92         /*
  93          * A coredumping process may sleep for an extended period in exit_mm(),
  94          * so the oom killer cannot assume that the process will promptly exit
  95          * and release memory.
  96          */
  97         return (task->flags & PF_EXITING) &&
  98                 !(task->signal->flags & SIGNAL_GROUP_COREDUMP);
  99 }
 100
 101 /* sysctls */
 102 extern int sysctl_oom_dump_tasks;
 103 extern int sysctl_oom_kill_allocating_task;
 104 extern int sysctl_panic_on_oom;
 105 #endif /* _INCLUDE_LINUX_OOM_H */