/* memcontrol.h - Memory Controller
   *
   * Copyright IBM Corporation, 2007
   * Author Balbir Singh <balbir@linux.vnet.ibm.com>
   *

   * Copyright 2007 OpenVZ SWsoft Inc
   * Author: Pavel Emelianov <xemul@openvz.org>
   *

   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   */
  
  #ifndef _LINUX_MEMCONTROL_H
  #define _LINUX_MEMCONTROL_H

  #include <linux/cgroup.h>

  #include <linux/vm_event_item.h>

  #include <linux/hardirq.h>

  #include <linux/jump_label.h>

  struct mem_cgroup;

  struct page;
  struct mm_struct;

  struct kmem_cache;

  /*
   * The corresponding mem_cgroup_stat_names is defined in mm/memcontrol.c,
   * These two lists should keep in accord with each other.
   */
  enum mem_cgroup_stat_index {
  	/*
  	 * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
  	 */
  	MEM_CGROUP_STAT_CACHE,		/* # of pages charged as cache */
  	MEM_CGROUP_STAT_RSS,		/* # of pages charged as anon rss */
  	MEM_CGROUP_STAT_RSS_HUGE,	/* # of pages charged as anon huge */
  	MEM_CGROUP_STAT_FILE_MAPPED,	/* # of pages charged as file rss */

  	MEM_CGROUP_STAT_WRITEBACK,	/* # of pages under writeback */

  	MEM_CGROUP_STAT_SWAP,		/* # of pages, swapped out */
  	MEM_CGROUP_STAT_NSTATS,

  };

  struct mem_cgroup_reclaim_cookie {
  	struct zone *zone;
  	int priority;
  	unsigned int generation;
  };

  enum mem_cgroup_events_index {
  	MEM_CGROUP_EVENTS_PGPGIN,	/* # of pages paged in */
  	MEM_CGROUP_EVENTS_PGPGOUT,	/* # of pages paged out */
  	MEM_CGROUP_EVENTS_PGFAULT,	/* # of page-faults */
  	MEM_CGROUP_EVENTS_PGMAJFAULT,	/* # of major page-faults */
  	MEM_CGROUP_EVENTS_NSTATS,
  	/* default hierarchy events */
  	MEMCG_LOW = MEM_CGROUP_EVENTS_NSTATS,
  	MEMCG_HIGH,
  	MEMCG_MAX,
  	MEMCG_OOM,
  	MEMCG_NR_EVENTS,
  };

  #ifdef CONFIG_MEMCG

  void mem_cgroup_events(struct mem_cgroup *memcg,
  		       enum mem_cgroup_events_index idx,
  		       unsigned int nr);
  
  bool mem_cgroup_low(struct mem_cgroup *root, struct mem_cgroup *memcg);

  int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm,
  			  gfp_t gfp_mask, struct mem_cgroup **memcgp);
  void mem_cgroup_commit_charge(struct page *page, struct mem_cgroup *memcg,
  			      bool lrucare);
  void mem_cgroup_cancel_charge(struct page *page, struct mem_cgroup *memcg);

  void mem_cgroup_uncharge(struct page *page);

  void mem_cgroup_uncharge_list(struct list_head *page_list);

  void mem_cgroup_migrate(struct page *oldpage, struct page *newpage,
  			bool lrucare);

  struct lruvec *mem_cgroup_zone_lruvec(struct zone *, struct mem_cgroup *);
  struct lruvec *mem_cgroup_page_lruvec(struct page *, struct zone *);

  bool mem_cgroup_is_descendant(struct mem_cgroup *memcg,
  			      struct mem_cgroup *root);
  bool task_in_mem_cgroup(struct task_struct *task, struct mem_cgroup *memcg);

  extern struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page);

  extern struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p);

  extern struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg);

  extern struct mem_cgroup *mem_cgroup_from_css(struct cgroup_subsys_state *css);

  static inline bool mm_match_cgroup(struct mm_struct *mm,
  				   struct mem_cgroup *memcg)

  {

  	struct mem_cgroup *task_memcg;

  	bool match = false;

  	rcu_read_lock();

  	task_memcg = mem_cgroup_from_task(rcu_dereference(mm->owner));

  	if (task_memcg)

  		match = mem_cgroup_is_descendant(task_memcg, memcg);

  	rcu_read_unlock();

  	return match;

  }

  extern struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *memcg);

  struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *,
  				   struct mem_cgroup *,
  				   struct mem_cgroup_reclaim_cookie *);

  void mem_cgroup_iter_break(struct mem_cgroup *, struct mem_cgroup *);

  /*
   * For memory reclaim.
   */

  int mem_cgroup_inactive_anon_is_low(struct lruvec *lruvec);

  bool mem_cgroup_lruvec_online(struct lruvec *lruvec);

  int mem_cgroup_select_victim_node(struct mem_cgroup *memcg);

  unsigned long mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list);

  void mem_cgroup_update_lru_size(struct lruvec *, enum lru_list, int);

  extern void mem_cgroup_print_oom_info(struct mem_cgroup *memcg,
  					struct task_struct *p);

  static inline void mem_cgroup_oom_enable(void)

  {

  	WARN_ON(current->memcg_oom.may_oom);
  	current->memcg_oom.may_oom = 1;

  }

  static inline void mem_cgroup_oom_disable(void)

  {

  	WARN_ON(!current->memcg_oom.may_oom);
  	current->memcg_oom.may_oom = 0;

  }

  static inline bool task_in_memcg_oom(struct task_struct *p)
  {

  	return p->memcg_oom.memcg;

  }

  bool mem_cgroup_oom_synchronize(bool wait);

  #ifdef CONFIG_MEMCG_SWAP

  extern int do_swap_account;
  #endif

  
  static inline bool mem_cgroup_disabled(void)
  {

  	if (memory_cgrp_subsys.disabled)

  		return true;
  	return false;
  }

  struct mem_cgroup *mem_cgroup_begin_page_stat(struct page *page);

  void mem_cgroup_update_page_stat(struct mem_cgroup *memcg,
  				 enum mem_cgroup_stat_index idx, int val);

  void mem_cgroup_end_page_stat(struct mem_cgroup *memcg);

  
  static inline void mem_cgroup_inc_page_stat(struct mem_cgroup *memcg,

  					    enum mem_cgroup_stat_index idx)

  {

  	mem_cgroup_update_page_stat(memcg, idx, 1);

  }

  static inline void mem_cgroup_dec_page_stat(struct mem_cgroup *memcg,

  					    enum mem_cgroup_stat_index idx)

  {

  	mem_cgroup_update_page_stat(memcg, idx, -1);

  }

  unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
  						gfp_t gfp_mask,
  						unsigned long *total_scanned);

  void __mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx);
  static inline void mem_cgroup_count_vm_event(struct mm_struct *mm,
  					     enum vm_event_item idx)
  {
  	if (mem_cgroup_disabled())
  		return;
  	__mem_cgroup_count_vm_event(mm, idx);
  }

  #ifdef CONFIG_TRANSPARENT_HUGEPAGE

  void mem_cgroup_split_huge_fixup(struct page *head);

  #endif

  #else /* CONFIG_MEMCG */

  struct mem_cgroup;

  static inline void mem_cgroup_events(struct mem_cgroup *memcg,
  				     enum mem_cgroup_events_index idx,
  				     unsigned int nr)
  {
  }
  
  static inline bool mem_cgroup_low(struct mem_cgroup *root,
  				  struct mem_cgroup *memcg)
  {
  	return false;
  }

  static inline int mem_cgroup_try_charge(struct page *page, struct mm_struct *mm,
  					gfp_t gfp_mask,
  					struct mem_cgroup **memcgp)

  {

  	*memcgp = NULL;

  	return 0;
  }

  static inline void mem_cgroup_commit_charge(struct page *page,
  					    struct mem_cgroup *memcg,
  					    bool lrucare)

  {
  }

  static inline void mem_cgroup_cancel_charge(struct page *page,
  					    struct mem_cgroup *memcg)

  {
  }

  static inline void mem_cgroup_uncharge(struct page *page)

  {
  }

  static inline void mem_cgroup_uncharge_list(struct list_head *page_list)

  {
  }

  static inline void mem_cgroup_migrate(struct page *oldpage,
  				      struct page *newpage,
  				      bool lrucare)

  {
  }

  static inline struct lruvec *mem_cgroup_zone_lruvec(struct zone *zone,
  						    struct mem_cgroup *memcg)

  {

  	return &zone->lruvec;

  }

  static inline struct lruvec *mem_cgroup_page_lruvec(struct page *page,
  						    struct zone *zone)

  {

  	return &zone->lruvec;

  }

  static inline struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page)
  {
  	return NULL;
  }

  static inline bool mm_match_cgroup(struct mm_struct *mm,

  		struct mem_cgroup *memcg)

  {

  	return true;

  }

  static inline bool task_in_mem_cgroup(struct task_struct *task,
  				      const struct mem_cgroup *memcg)

  {

  	return true;

  }

  static inline struct cgroup_subsys_state
  		*mem_cgroup_css(struct mem_cgroup *memcg)

  {
  	return NULL;
  }

  static inline struct mem_cgroup *
  mem_cgroup_iter(struct mem_cgroup *root,
  		struct mem_cgroup *prev,
  		struct mem_cgroup_reclaim_cookie *reclaim)
  {
  	return NULL;
  }
  
  static inline void mem_cgroup_iter_break(struct mem_cgroup *root,
  					 struct mem_cgroup *prev)
  {
  }

  static inline bool mem_cgroup_disabled(void)
  {
  	return true;
  }

  static inline int

  mem_cgroup_inactive_anon_is_low(struct lruvec *lruvec)

  {
  	return 1;
  }

  static inline bool mem_cgroup_lruvec_online(struct lruvec *lruvec)
  {
  	return true;
  }

  static inline unsigned long

  mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list lru)

  {
  	return 0;
  }

  static inline void
  mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru,
  			      int increment)

  {

  }

  static inline void
  mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
  {
  }

  static inline struct mem_cgroup *mem_cgroup_begin_page_stat(struct page *page)

  {

  	return NULL;

  }

  static inline void mem_cgroup_end_page_stat(struct mem_cgroup *memcg)

  {
  }

  static inline void mem_cgroup_oom_enable(void)

  {
  }

  static inline void mem_cgroup_oom_disable(void)

  {
  }

  static inline bool task_in_memcg_oom(struct task_struct *p)
  {
  	return false;
  }

  static inline bool mem_cgroup_oom_synchronize(bool wait)

  {
  	return false;
  }

  static inline void mem_cgroup_inc_page_stat(struct mem_cgroup *memcg,

  					    enum mem_cgroup_stat_index idx)

  {
  }

  static inline void mem_cgroup_dec_page_stat(struct mem_cgroup *memcg,

  					    enum mem_cgroup_stat_index idx)

  {
  }

  static inline

  unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order,
  					    gfp_t gfp_mask,
  					    unsigned long *total_scanned)

  {

  	return 0;

  }

  static inline void mem_cgroup_split_huge_fixup(struct page *head)

  {
  }

  static inline
  void mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx)
  {
  }

  #endif /* CONFIG_MEMCG */

  enum {
  	UNDER_LIMIT,
  	SOFT_LIMIT,
  	OVER_LIMIT,
  };
  
  struct sock;

  #if defined(CONFIG_INET) && defined(CONFIG_MEMCG_KMEM)

  void sock_update_memcg(struct sock *sk);
  void sock_release_memcg(struct sock *sk);
  #else
  static inline void sock_update_memcg(struct sock *sk)
  {
  }
  static inline void sock_release_memcg(struct sock *sk)
  {
  }

  #endif /* CONFIG_INET && CONFIG_MEMCG_KMEM */

  
  #ifdef CONFIG_MEMCG_KMEM

  extern struct static_key memcg_kmem_enabled_key;

  extern int memcg_nr_cache_ids;

  extern void memcg_get_cache_ids(void);
  extern void memcg_put_cache_ids(void);

  
  /*
   * Helper macro to loop through all memcg-specific caches. Callers must still
   * check if the cache is valid (it is either valid or NULL).
   * the slab_mutex must be held when looping through those caches
   */

  #define for_each_memcg_cache_index(_idx)	\

  	for ((_idx) = 0; (_idx) < memcg_nr_cache_ids; (_idx)++)

  static inline bool memcg_kmem_enabled(void)
  {

  	return static_key_false(&memcg_kmem_enabled_key);

  }

  bool memcg_kmem_is_active(struct mem_cgroup *memcg);

  /*
   * In general, we'll do everything in our power to not incur in any overhead
   * for non-memcg users for the kmem functions. Not even a function call, if we
   * can avoid it.
   *
   * Therefore, we'll inline all those functions so that in the best case, we'll
   * see that kmemcg is off for everybody and proceed quickly.  If it is on,
   * we'll still do most of the flag checking inline. We check a lot of
   * conditions, but because they are pretty simple, they are expected to be
   * fast.
   */
  bool __memcg_kmem_newpage_charge(gfp_t gfp, struct mem_cgroup **memcg,
  					int order);
  void __memcg_kmem_commit_charge(struct page *page,
  				       struct mem_cgroup *memcg, int order);
  void __memcg_kmem_uncharge_pages(struct page *page, int order);

  int memcg_cache_id(struct mem_cgroup *memcg);

  struct kmem_cache *__memcg_kmem_get_cache(struct kmem_cache *cachep);
  void __memcg_kmem_put_cache(struct kmem_cache *cachep);

  struct mem_cgroup *__mem_cgroup_from_kmem(void *ptr);

  int memcg_charge_kmem(struct mem_cgroup *memcg, gfp_t gfp,
  		      unsigned long nr_pages);
  void memcg_uncharge_kmem(struct mem_cgroup *memcg, unsigned long nr_pages);

  /**
   * memcg_kmem_newpage_charge: verify if a new kmem allocation is allowed.
   * @gfp: the gfp allocation flags.
   * @memcg: a pointer to the memcg this was charged against.
   * @order: allocation order.
   *
   * returns true if the memcg where the current task belongs can hold this
   * allocation.
   *
   * We return true automatically if this allocation is not to be accounted to
   * any memcg.
   */
  static inline bool
  memcg_kmem_newpage_charge(gfp_t gfp, struct mem_cgroup **memcg, int order)
  {
  	if (!memcg_kmem_enabled())
  		return true;

  	if (gfp & __GFP_NOACCOUNT)
  		return true;

  	/*
  	 * __GFP_NOFAIL allocations will move on even if charging is not
  	 * possible. Therefore we don't even try, and have this allocation

  	 * unaccounted. We could in theory charge it forcibly, but we hope
  	 * those allocations are rare, and won't be worth the trouble.

  	 */

  	if (gfp & __GFP_NOFAIL)

  		return true;
  	if (in_interrupt() || (!current->mm) || (current->flags & PF_KTHREAD))
  		return true;
  
  	/* If the test is dying, just let it go. */
  	if (unlikely(fatal_signal_pending(current)))
  		return true;
  
  	return __memcg_kmem_newpage_charge(gfp, memcg, order);
  }
  
  /**
   * memcg_kmem_uncharge_pages: uncharge pages from memcg
   * @page: pointer to struct page being freed
   * @order: allocation order.

   */
  static inline void
  memcg_kmem_uncharge_pages(struct page *page, int order)
  {
  	if (memcg_kmem_enabled())
  		__memcg_kmem_uncharge_pages(page, order);
  }
  
  /**
   * memcg_kmem_commit_charge: embeds correct memcg in a page
   * @page: pointer to struct page recently allocated
   * @memcg: the memcg structure we charged against
   * @order: allocation order.
   *
   * Needs to be called after memcg_kmem_newpage_charge, regardless of success or
   * failure of the allocation. if @page is NULL, this function will revert the

   * charges. Otherwise, it will commit @page to @memcg.

   */
  static inline void
  memcg_kmem_commit_charge(struct page *page, struct mem_cgroup *memcg, int order)
  {
  	if (memcg_kmem_enabled() && memcg)
  		__memcg_kmem_commit_charge(page, memcg, order);
  }

  /**
   * memcg_kmem_get_cache: selects the correct per-memcg cache for allocation
   * @cachep: the original global kmem cache
   * @gfp: allocation flags.
   *

   * All memory allocated from a per-memcg cache is charged to the owner memcg.

   */
  static __always_inline struct kmem_cache *
  memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp)
  {
  	if (!memcg_kmem_enabled())
  		return cachep;

  	if (gfp & __GFP_NOACCOUNT)
  		return cachep;

  	if (gfp & __GFP_NOFAIL)
  		return cachep;
  	if (in_interrupt() || (!current->mm) || (current->flags & PF_KTHREAD))
  		return cachep;
  	if (unlikely(fatal_signal_pending(current)))
  		return cachep;

  	return __memcg_kmem_get_cache(cachep);

  }

  
  static __always_inline void memcg_kmem_put_cache(struct kmem_cache *cachep)
  {
  	if (memcg_kmem_enabled())
  		__memcg_kmem_put_cache(cachep);
  }

  
  static __always_inline struct mem_cgroup *mem_cgroup_from_kmem(void *ptr)
  {
  	if (!memcg_kmem_enabled())
  		return NULL;
  	return __mem_cgroup_from_kmem(ptr);
  }

  #else

  #define for_each_memcg_cache_index(_idx)	\
  	for (; NULL; )

  static inline bool memcg_kmem_enabled(void)
  {
  	return false;
  }

  static inline bool memcg_kmem_is_active(struct mem_cgroup *memcg)
  {
  	return false;
  }

  static inline bool
  memcg_kmem_newpage_charge(gfp_t gfp, struct mem_cgroup **memcg, int order)
  {
  	return true;
  }
  
  static inline void memcg_kmem_uncharge_pages(struct page *page, int order)
  {
  }
  
  static inline void
  memcg_kmem_commit_charge(struct page *page, struct mem_cgroup *memcg, int order)
  {
  }

  
  static inline int memcg_cache_id(struct mem_cgroup *memcg)
  {
  	return -1;
  }

  static inline void memcg_get_cache_ids(void)
  {
  }
  
  static inline void memcg_put_cache_ids(void)
  {
  }

  static inline struct kmem_cache *
  memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp)
  {
  	return cachep;
  }

  
  static inline void memcg_kmem_put_cache(struct kmem_cache *cachep)
  {
  }

  
  static inline struct mem_cgroup *mem_cgroup_from_kmem(void *ptr)
  {
  	return NULL;
  }

  #endif /* CONFIG_MEMCG_KMEM */

  #endif /* _LINUX_MEMCONTROL_H */