#ifndef __INCLUDE_LINUX_OOM_H
#define __INCLUDE_LINUX_OOM_H


#include <linux/sched.h>
#include <linux/types.h>
#include <linux/nodemask.h>
#include <uapi/linux/oom.h>
#include <linux/spinlock_types.h>
#include <linux/wait.h>

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

/*
 * Types of limitations to the nodes from which allocations may occur
 */
enum oom_constraint {
	CONSTRAINT_NONE,
	CONSTRAINT_CPUSET,
	CONSTRAINT_MEMORY_POLICY,
	CONSTRAINT_MEMCG,
};

enum oom_scan_t {
	OOM_SCAN_OK,		/* scan thread and find its badness */
	OOM_SCAN_CONTINUE,	/* do not consider thread for oom kill */
	OOM_SCAN_SELECT,	/* always select this thread first */
};

struct oom_context {
	struct task_struct *owner;
	struct task_struct *victim;
	bool marked;
	unsigned long oom_start;
	unsigned long oom_end;
	unsigned long overdraft;
	int rage;
	wait_queue_head_t waitq;
};

extern void init_oom_context(struct oom_context *ctx);
extern void release_oom_context(struct oom_context *ctx);

/* Thread is the potential origin of an oom condition; kill first on oom */
#define OOM_FLAG_ORIGIN		((__force oom_flags_t)0x1)

static inline void set_current_oom_origin(void)
{
	current->signal->oom_flags |= OOM_FLAG_ORIGIN;
}

static inline void clear_current_oom_origin(void)
{
	current->signal->oom_flags &= ~OOM_FLAG_ORIGIN;
}

static inline bool oom_task_origin(const struct task_struct *p)
{
	return !!(p->signal->oom_flags & OOM_FLAG_ORIGIN);
}

/* linux/mm/oom_group.c */
extern int get_task_oom_score_adj(struct task_struct *t);

extern void mark_oom_victim(struct task_struct *tsk);

extern unsigned long oom_badness(struct task_struct *p,
		struct mem_cgroup *memcg, const nodemask_t *nodemask,
		unsigned long totalpages, unsigned long *overdraft);

static inline bool oom_worse(unsigned long points, unsigned long overdraft,
		unsigned long *chosen_points, unsigned long *max_overdraft)
{
	if (overdraft > *max_overdraft) {
		*max_overdraft = overdraft;
		*chosen_points = points;
		return true;
	}
	if (overdraft == *max_overdraft && points > *chosen_points) {
		*chosen_points = points;
		return true;
	}
	return false;
}

extern void oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order,
			     unsigned long points, unsigned long overdraft,
			     unsigned long totalpages,
			     struct mem_cgroup *memcg, nodemask_t *nodemask,
			     const char *message);

extern bool oom_trylock(struct mem_cgroup *memcg);
extern void oom_unlock(struct mem_cgroup *memcg);

extern void check_panic_on_oom(enum oom_constraint constraint, gfp_t gfp_mask,
			       int order, const nodemask_t *nodemask);

extern enum oom_scan_t oom_scan_process_thread(struct task_struct *task,
		unsigned long totalpages, const nodemask_t *nodemask,
		bool force_kill);

extern void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask,
		int order, nodemask_t *mask, bool force_kill);

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_disabled;

static inline void oom_killer_disable(void)
{
	oom_killer_disabled = true;
}

static inline void oom_killer_enable(void)
{
	oom_killer_disabled = false;
}

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;
extern int sysctl_oom_relaxation;
#endif /* _INCLUDE_LINUX_OOM_H */