[GitHub/mt8127/android_kernel_alcatel_ttab.git] / include / linux / res_counter.h

#ifndef __RES_COUNTER_H__
#define __RES_COUNTER_H__

/*
 * Resource Counters
 * Contain common data types and routines for resource accounting
 *
 * Copyright 2007 OpenVZ SWsoft Inc
 *
 * Author: Pavel Emelianov <xemul@openvz.org>
 *
 * See Documentation/controllers/resource_counter.txt for more
 * info about what this counter is.
 */

#include <linux/cgroup.h>

/*
 * The core object. the cgroup that wishes to account for some
 * resource may include this counter into its structures and use
 * the helpers described beyond
 */

struct res_counter {
	/*
	 * the current resource consumption level
	 */
	unsigned long long usage;
	/*
	 * the maximal value of the usage from the counter creation
	 */
	unsigned long long max_usage;
	/*
	 * the limit that usage cannot exceed
	 */
	unsigned long long limit;
	/*
	 * the number of unsuccessful attempts to consume the resource
	 */
	unsigned long long failcnt;
	/*
	 * the lock to protect all of the above.
	 * the routines below consider this to be IRQ-safe
	 */
	spinlock_t lock;
};

/**
 * Helpers to interact with userspace
 * res_counter_read_u64() - returns the value of the specified member.
 * res_counter_read/_write - put/get the specified fields from the
 * res_counter struct to/from the user
 *
 * @counter:     the counter in question
 * @member:  the field to work with (see RES_xxx below)
 * @buf:     the buffer to opeate on,...
 * @nbytes:  its size...
 * @pos:     and the offset.
 */

u64 res_counter_read_u64(struct res_counter *counter, int member);

ssize_t res_counter_read(struct res_counter *counter, int member,
		const char __user *buf, size_t nbytes, loff_t *pos,
		int (*read_strategy)(unsigned long long val, char *s));

typedef int (*write_strategy_fn)(const char *buf, unsigned long long *val);

int res_counter_memparse_write_strategy(const char *buf,
					unsigned long long *res);

int res_counter_write(struct res_counter *counter, int member,
		      const char *buffer, write_strategy_fn write_strategy);

/*
 * the field descriptors. one for each member of res_counter
 */

enum {
	RES_USAGE,
	RES_MAX_USAGE,
	RES_LIMIT,
	RES_FAILCNT,
};

/*
 * helpers for accounting
 */

void res_counter_init(struct res_counter *counter);

/*
 * charge - try to consume more resource.
 *
 * @counter: the counter
 * @val: the amount of the resource. each controller defines its own
 *       units, e.g. numbers, bytes, Kbytes, etc
 *
 * returns 0 on success and <0 if the counter->usage will exceed the
 * counter->limit _locked call expects the counter->lock to be taken
 */

int __must_check res_counter_charge_locked(struct res_counter *counter,
		unsigned long val);
int __must_check res_counter_charge(struct res_counter *counter,
		unsigned long val);

/*
 * uncharge - tell that some portion of the resource is released
 *
 * @counter: the counter
 * @val: the amount of the resource
 *
 * these calls check for usage underflow and show a warning on the console
 * _locked call expects the counter->lock to be taken
 */

void res_counter_uncharge_locked(struct res_counter *counter, unsigned long val);
void res_counter_uncharge(struct res_counter *counter, unsigned long val);

static inline bool res_counter_limit_check_locked(struct res_counter *cnt)
{
	if (cnt->usage < cnt->limit)
		return true;

	return false;
}

/*
 * Helper function to detect if the cgroup is within it's limit or
 * not. It's currently called from cgroup_rss_prepare()
 */
static inline bool res_counter_check_under_limit(struct res_counter *cnt)
{
	bool ret;
	unsigned long flags;

	spin_lock_irqsave(&cnt->lock, flags);
	ret = res_counter_limit_check_locked(cnt);
	spin_unlock_irqrestore(&cnt->lock, flags);
	return ret;
}

static inline void res_counter_reset_max(struct res_counter *cnt)
{
	unsigned long flags;

	spin_lock_irqsave(&cnt->lock, flags);
	cnt->max_usage = cnt->usage;
	spin_unlock_irqrestore(&cnt->lock, flags);
}

static inline void res_counter_reset_failcnt(struct res_counter *cnt)
{
	unsigned long flags;

	spin_lock_irqsave(&cnt->lock, flags);
	cnt->failcnt = 0;
	spin_unlock_irqrestore(&cnt->lock, flags);
}

static inline int res_counter_set_limit(struct res_counter *cnt,
		unsigned long long limit)
{
	unsigned long flags;
	int ret = -EBUSY;

	spin_lock_irqsave(&cnt->lock, flags);
	if (cnt->usage <= limit) {
		cnt->limit = limit;
		ret = 0;
	}
	spin_unlock_irqrestore(&cnt->lock, flags);
	return ret;
}

#endif
Commit	Line	Data
e552b661 PE	1	#ifndef __RES_COUNTER_H__
	2	#define __RES_COUNTER_H__
	3
	4	/*
	5	* Resource Counters
	6	* Contain common data types and routines for resource accounting
	7	*
	8	* Copyright 2007 OpenVZ SWsoft Inc
	9	*
	10	* Author: Pavel Emelianov <xemul@openvz.org>
	11	*
faebe9fd PE	12	* See Documentation/controllers/resource_counter.txt for more
faebe9fd PE	13	* info about what this counter is.
e552b661 PE	14	*/
	15
	16	#include <linux/cgroup.h>
	17
	18	/*
	19	* The core object. the cgroup that wishes to account for some
	20	* resource may include this counter into its structures and use
	21	* the helpers described beyond
	22	*/
	23
	24	struct res_counter {
	25	/*
	26	* the current resource consumption level
	27	*/
0eea1030	28	unsigned long long usage;
c84872e1 PE	29	/*
	30	* the maximal value of the usage from the counter creation
	31	*/
	32	unsigned long long max_usage;
e552b661 PE	33	/*
	34	* the limit that usage cannot exceed
	35	*/
0eea1030	36	unsigned long long limit;
e552b661 PE	37	/*
	38	* the number of unsuccessful attempts to consume the resource
	39	*/
0eea1030	40	unsigned long long failcnt;
e552b661 PE	41	/*
	42	* the lock to protect all of the above.
	43	* the routines below consider this to be IRQ-safe
	44	*/
	45	spinlock_t lock;
	46	};
	47
2c7eabf3	48	/**
e552b661	49	* Helpers to interact with userspace
2c7eabf3	50	* res_counter_read_u64() - returns the value of the specified member.
e552b661 PE	51	* res_counter_read/_write - put/get the specified fields from the
	52	* res_counter struct to/from the user
	53	*
	54	* @counter: the counter in question
	55	* @member: the field to work with (see RES_xxx below)
	56	* @buf: the buffer to opeate on,...
	57	* @nbytes: its size...
	58	* @pos: and the offset.
	59	*/
	60
2c7eabf3 PM	61	u64 res_counter_read_u64(struct res_counter *counter, int member);
2c7eabf3 PM	62
e552b661	63	ssize_t res_counter_read(struct res_counter *counter, int member,
0eea1030 BS	64	const char __user buf, size_t nbytes, loff_t pos,
0eea1030 BS	65	int (read_strategy)(unsigned long long val, char s));
856c13aa PM	66
	67	typedef int (write_strategy_fn)(const char buf, unsigned long long *val);
	68
	69	int res_counter_memparse_write_strategy(const char *buf,
	70	unsigned long long *res);
	71
	72	int res_counter_write(struct res_counter *counter, int member,
	73	const char *buffer, write_strategy_fn write_strategy);
e552b661 PE	74
	75	/*
	76	* the field descriptors. one for each member of res_counter
	77	*/
	78
	79	enum {
	80	RES_USAGE,
c84872e1	81	RES_MAX_USAGE,
e552b661 PE	82	RES_LIMIT,
	83	RES_FAILCNT,
	84	};
	85
	86	/*
	87	* helpers for accounting
	88	*/
	89
	90	void res_counter_init(struct res_counter *counter);
	91
	92	/*
	93	* charge - try to consume more resource.
	94	*
	95	* @counter: the counter
	96	* @val: the amount of the resource. each controller defines its own
	97	* units, e.g. numbers, bytes, Kbytes, etc
	98	*
	99	* returns 0 on success and <0 if the counter->usage will exceed the
	100	* counter->limit _locked call expects the counter->lock to be taken
	101	*/
	102
f2992db2 PE	103	int __must_check res_counter_charge_locked(struct res_counter *counter,
	104	unsigned long val);
	105	int __must_check res_counter_charge(struct res_counter *counter,
	106	unsigned long val);
e552b661 PE	107
	108	/*
	109	* uncharge - tell that some portion of the resource is released
	110	*
	111	* @counter: the counter
	112	* @val: the amount of the resource
	113	*
	114	* these calls check for usage underflow and show a warning on the console
	115	* _locked call expects the counter->lock to be taken
	116	*/
	117
	118	void res_counter_uncharge_locked(struct res_counter *counter, unsigned long val);
	119	void res_counter_uncharge(struct res_counter *counter, unsigned long val);
	120
66e1707b BS	121	static inline bool res_counter_limit_check_locked(struct res_counter *cnt)
	122	{
	123	if (cnt->usage < cnt->limit)
	124	return true;
	125
	126	return false;
	127	}
	128
	129	/*
	130	* Helper function to detect if the cgroup is within it's limit or
	131	* not. It's currently called from cgroup_rss_prepare()
	132	*/
	133	static inline bool res_counter_check_under_limit(struct res_counter *cnt)
	134	{
	135	bool ret;
	136	unsigned long flags;
	137
	138	spin_lock_irqsave(&cnt->lock, flags);
	139	ret = res_counter_limit_check_locked(cnt);
	140	spin_unlock_irqrestore(&cnt->lock, flags);
	141	return ret;
	142	}
	143
c84872e1 PE	144	static inline void res_counter_reset_max(struct res_counter *cnt)
	145	{
	146	unsigned long flags;
	147
	148	spin_lock_irqsave(&cnt->lock, flags);
	149	cnt->max_usage = cnt->usage;
	150	spin_unlock_irqrestore(&cnt->lock, flags);
	151	}
	152
29f2a4da PE	153	static inline void res_counter_reset_failcnt(struct res_counter *cnt)
	154	{
	155	unsigned long flags;
	156
	157	spin_lock_irqsave(&cnt->lock, flags);
	158	cnt->failcnt = 0;
	159	spin_unlock_irqrestore(&cnt->lock, flags);
	160	}
12b98044 KH	161
	162	static inline int res_counter_set_limit(struct res_counter *cnt,
	163	unsigned long long limit)
	164	{
	165	unsigned long flags;
	166	int ret = -EBUSY;
	167
	168	spin_lock_irqsave(&cnt->lock, flags);
11d55d2c	169	if (cnt->usage <= limit) {
12b98044 KH	170	cnt->limit = limit;
	171	ret = 0;
	172	}
	173	spin_unlock_irqrestore(&cnt->lock, flags);
	174	return ret;
	175	}
	176
e552b661	177	#endif