1#ifndef __LINUX_PAGE_CGROUP_H
  2#define __LINUX_PAGE_CGROUP_H
  3
  4enum {
  5	/* flags for mem_cgroup */
  6	PCG_LOCK,  /* Lock for pc->mem_cgroup and following bits. */
  7	PCG_CACHE, /* charged as cache */
  8	PCG_USED, /* this object is in use. */
  9	PCG_MIGRATION, /* under page migration */
 10	/* flags for mem_cgroup and file and I/O status */
 11	PCG_MOVE_LOCK, /* For race between move_account v.s. following bits */
 12	PCG_FILE_MAPPED, /* page is accounted as "mapped" */
 13	/* No lock in page_cgroup */
 14	PCG_ACCT_LRU, /* page has been accounted for (under lru_lock) */
 15	__NR_PCG_FLAGS,
 16};
 17
 18#ifndef __GENERATING_BOUNDS_H
 19#include <generated/bounds.h>
 20
 21#ifdef CONFIG_CGROUP_MEM_RES_CTLR
 22#include <linux/bit_spinlock.h>
 23
 24/*
 25 * Page Cgroup can be considered as an extended mem_map.
 26 * A page_cgroup page is associated with every page descriptor. The
 27 * page_cgroup helps us identify information about the cgroup
 28 * All page cgroups are allocated at boot or memory hotplug event,
 29 * then the page cgroup for pfn always exists.
 30 */
 31struct page_cgroup {
 32	unsigned long flags;
 33	struct mem_cgroup *mem_cgroup;
 34	struct list_head lru;		/* per cgroup LRU list */
 35};
 36
 37void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat);
 38
 39#ifdef CONFIG_SPARSEMEM
 40static inline void __init page_cgroup_init_flatmem(void)
 41{
 42}
 43extern void __init page_cgroup_init(void);
 44#else
 45void __init page_cgroup_init_flatmem(void);
 46static inline void __init page_cgroup_init(void)
 47{
 48}
 49#endif
 50
 51struct page_cgroup *lookup_page_cgroup(struct page *page);
 52struct page *lookup_cgroup_page(struct page_cgroup *pc);
 53
 54#define TESTPCGFLAG(uname, lname)			\
 55static inline int PageCgroup##uname(struct page_cgroup *pc)	\
 56	{ return test_bit(PCG_##lname, &pc->flags); }
 57
 58#define SETPCGFLAG(uname, lname)			\
 59static inline void SetPageCgroup##uname(struct page_cgroup *pc)\
 60	{ set_bit(PCG_##lname, &pc->flags);  }
 61
 62#define CLEARPCGFLAG(uname, lname)			\
 63static inline void ClearPageCgroup##uname(struct page_cgroup *pc)	\
 64	{ clear_bit(PCG_##lname, &pc->flags);  }
 65
 66#define TESTCLEARPCGFLAG(uname, lname)			\
 67static inline int TestClearPageCgroup##uname(struct page_cgroup *pc)	\
 68	{ return test_and_clear_bit(PCG_##lname, &pc->flags);  }
 69
 70/* Cache flag is set only once (at allocation) */
 71TESTPCGFLAG(Cache, CACHE)
 72CLEARPCGFLAG(Cache, CACHE)
 73SETPCGFLAG(Cache, CACHE)
 74
 75TESTPCGFLAG(Used, USED)
 76CLEARPCGFLAG(Used, USED)
 77SETPCGFLAG(Used, USED)
 78
 79SETPCGFLAG(AcctLRU, ACCT_LRU)
 80CLEARPCGFLAG(AcctLRU, ACCT_LRU)
 81TESTPCGFLAG(AcctLRU, ACCT_LRU)
 82TESTCLEARPCGFLAG(AcctLRU, ACCT_LRU)
 83
 84
 85SETPCGFLAG(FileMapped, FILE_MAPPED)
 86CLEARPCGFLAG(FileMapped, FILE_MAPPED)
 87TESTPCGFLAG(FileMapped, FILE_MAPPED)
 88
 89SETPCGFLAG(Migration, MIGRATION)
 90CLEARPCGFLAG(Migration, MIGRATION)
 91TESTPCGFLAG(Migration, MIGRATION)
 92
 93static inline void lock_page_cgroup(struct page_cgroup *pc)
 94{
 95	/*
 96	 * Don't take this lock in IRQ context.
 97	 * This lock is for pc->mem_cgroup, USED, CACHE, MIGRATION
 98	 */
 99	bit_spin_lock(PCG_LOCK, &pc->flags);
100}
101
102static inline void unlock_page_cgroup(struct page_cgroup *pc)
103{
104	bit_spin_unlock(PCG_LOCK, &pc->flags);
105}
106
107static inline void move_lock_page_cgroup(struct page_cgroup *pc,
108	unsigned long *flags)
109{
110	/*
111	 * We know updates to pc->flags of page cache's stats are from both of
112	 * usual context or IRQ context. Disable IRQ to avoid deadlock.
113	 */
114	local_irq_save(*flags);
115	bit_spin_lock(PCG_MOVE_LOCK, &pc->flags);
116}
117
118static inline void move_unlock_page_cgroup(struct page_cgroup *pc,
119	unsigned long *flags)
120{
121	bit_spin_unlock(PCG_MOVE_LOCK, &pc->flags);
122	local_irq_restore(*flags);
123}
124
125#ifdef CONFIG_SPARSEMEM
126#define PCG_ARRAYID_WIDTH	SECTIONS_SHIFT
127#else
128#define PCG_ARRAYID_WIDTH	NODES_SHIFT
129#endif
130
131#if (PCG_ARRAYID_WIDTH > BITS_PER_LONG - NR_PCG_FLAGS)
132#error Not enough space left in pc->flags to store page_cgroup array IDs
133#endif
134
135/* pc->flags: ARRAY-ID | FLAGS */
136
137#define PCG_ARRAYID_MASK	((1UL << PCG_ARRAYID_WIDTH) - 1)
138
139#define PCG_ARRAYID_OFFSET	(BITS_PER_LONG - PCG_ARRAYID_WIDTH)
140/*
141 * Zero the shift count for non-existent fields, to prevent compiler
142 * warnings and ensure references are optimized away.
143 */
144#define PCG_ARRAYID_SHIFT	(PCG_ARRAYID_OFFSET * (PCG_ARRAYID_WIDTH != 0))
145
146static inline void set_page_cgroup_array_id(struct page_cgroup *pc,
147					    unsigned long id)
148{
149	pc->flags &= ~(PCG_ARRAYID_MASK << PCG_ARRAYID_SHIFT);
150	pc->flags |= (id & PCG_ARRAYID_MASK) << PCG_ARRAYID_SHIFT;
151}
152
153static inline unsigned long page_cgroup_array_id(struct page_cgroup *pc)
154{
155	return (pc->flags >> PCG_ARRAYID_SHIFT) & PCG_ARRAYID_MASK;
156}
157
158#else /* CONFIG_CGROUP_MEM_RES_CTLR */
159struct page_cgroup;
160
161static inline void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat)
162{
163}
164
165static inline struct page_cgroup *lookup_page_cgroup(struct page *page)
166{
167	return NULL;
168}
169
170static inline void page_cgroup_init(void)
171{
172}
173
174static inline void __init page_cgroup_init_flatmem(void)
175{
176}
177
178#endif /* CONFIG_CGROUP_MEM_RES_CTLR */
179
180#include <linux/swap.h>
181
182#ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
183extern unsigned short swap_cgroup_cmpxchg(swp_entry_t ent,
184					unsigned short old, unsigned short new);
185extern unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id);
186extern unsigned short lookup_swap_cgroup(swp_entry_t ent);
187extern int swap_cgroup_swapon(int type, unsigned long max_pages);
188extern void swap_cgroup_swapoff(int type);
189#else
190
191static inline
192unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id)
193{
194	return 0;
195}
196
197static inline
198unsigned short lookup_swap_cgroup(swp_entry_t ent)
199{
200	return 0;
201}
202
203static inline int
204swap_cgroup_swapon(int type, unsigned long max_pages)
205{
206	return 0;
207}
208
209static inline void swap_cgroup_swapoff(int type)
210{
211	return;
212}
213
214#endif /* CONFIG_CGROUP_MEM_RES_CTLR_SWAP */
215
216#endif /* !__GENERATING_BOUNDS_H */
217
218#endif /* __LINUX_PAGE_CGROUP_H */