LXR linux/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
  10struct zonelist;
  11struct notifier_block;
  12struct mem_cgroup;
  13struct 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 */
  19struct 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 */
  39enum oom_constraint {
  40        CONSTRAINT_NONE,
  41        CONSTRAINT_CPUSET,
  42        CONSTRAINT_MEMORY_POLICY,
  43        CONSTRAINT_MEMCG,
  44};
  45
  46enum 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
  56extern struct mutex oom_lock;
  57
  58static inline void set_current_oom_origin(void)
  59{
  60        current->signal->oom_flags |= OOM_FLAG_ORIGIN;
  61}
  62
  63static inline void clear_current_oom_origin(void)
  64{
  65        current->signal->oom_flags &= ~OOM_FLAG_ORIGIN;
  66}
  67
  68static inline bool oom_task_origin(const struct task_struct *p)
  69{
  70        return !!(p->signal->oom_flags & OOM_FLAG_ORIGIN);
  71}
  72
  73extern void mark_oom_victim(struct task_struct *tsk);
  74
  75extern unsigned long oom_badness(struct task_struct *p,
  76                struct mem_cgroup *memcg, const nodemask_t *nodemask,
  77                unsigned long totalpages);
  78
  79extern 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
  83extern void check_panic_on_oom(struct oom_control *oc,
  84                               enum oom_constraint constraint,
  85                               struct mem_cgroup *memcg);
  86
  87extern enum oom_scan_t oom_scan_process_thread(struct oom_control *oc,
  88                struct task_struct *task, unsigned long totalpages);
  89
  90extern bool out_of_memory(struct oom_control *oc);
  91
  92extern void exit_oom_victim(struct task_struct *tsk);
  93
  94extern int register_oom_notifier(struct notifier_block *nb);
  95extern int unregister_oom_notifier(struct notifier_block *nb);
  96
  97extern bool oom_killer_disabled;
  98extern bool oom_killer_disable(void);
  99extern void oom_killer_enable(void);
 100
 101extern struct task_struct *find_lock_task_mm(struct task_struct *p);
 102
 103static 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 */
 115extern int sysctl_oom_dump_tasks;
 116extern int sysctl_oom_kill_allocating_task;
 117extern int sysctl_panic_on_oom;
 118#endif /* _INCLUDE_LINUX_OOM_H */
 119