root/include/linux/oom.h

INCLUDED FROM

DEFINITIONS

1. set_current_oom_origin
2. clear_current_oom_origin
3. oom_task_origin
4. oom_killer_disable
5. oom_killer_enable
6. oom_gfp_allowed

#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>

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_ABORT,         /* abort the iteration and return */
        OOM_SCAN_SELECT,        /* always select this thread first */
};

/* 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);
}

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

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

extern bool oom_zonelist_trylock(struct zonelist *zonelist, gfp_t gfp_flags);
extern void oom_zonelist_unlock(struct zonelist *zonelist, gfp_t gfp_flags);

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 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;
}

static inline bool oom_gfp_allowed(gfp_t gfp_mask)
{
        return (gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY);
}

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;
#endif /* _INCLUDE_LINUX_OOM_H */