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![Sha Zhengju](/assets/img/avatar_default.png)
RESOURCE_MAX is far too general name, change it to RES_COUNTER_MAX. Signed-off-by: Sha Zhengju <handai.szj@taobao.com> Signed-off-by: Qiang Huang <h.huangqiang@huawei.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Jeff Liu <jeff.liu@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
227 lines
5.7 KiB
C
227 lines
5.7 KiB
C
#ifndef __RES_COUNTER_H__
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#define __RES_COUNTER_H__
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/*
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* Resource Counters
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* Contain common data types and routines for resource accounting
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*
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* Copyright 2007 OpenVZ SWsoft Inc
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*
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* Author: Pavel Emelianov <xemul@openvz.org>
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*
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* See Documentation/cgroups/resource_counter.txt for more
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* info about what this counter is.
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*/
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#include <linux/spinlock.h>
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#include <linux/errno.h>
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/*
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* The core object. the cgroup that wishes to account for some
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* resource may include this counter into its structures and use
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* the helpers described beyond
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*/
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struct res_counter {
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/*
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* the current resource consumption level
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*/
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unsigned long long usage;
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/*
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* the maximal value of the usage from the counter creation
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*/
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unsigned long long max_usage;
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/*
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* the limit that usage cannot exceed
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*/
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unsigned long long limit;
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/*
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* the limit that usage can be exceed
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*/
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unsigned long long soft_limit;
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/*
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* the number of unsuccessful attempts to consume the resource
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*/
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unsigned long long failcnt;
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/*
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* the lock to protect all of the above.
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* the routines below consider this to be IRQ-safe
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*/
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spinlock_t lock;
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/*
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* Parent counter, used for hierarchial resource accounting
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*/
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struct res_counter *parent;
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};
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#define RES_COUNTER_MAX ULLONG_MAX
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/**
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* Helpers to interact with userspace
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* res_counter_read_u64() - returns the value of the specified member.
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* res_counter_read/_write - put/get the specified fields from the
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* res_counter struct to/from the user
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*
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* @counter: the counter in question
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* @member: the field to work with (see RES_xxx below)
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* @buf: the buffer to opeate on,...
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* @nbytes: its size...
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* @pos: and the offset.
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*/
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u64 res_counter_read_u64(struct res_counter *counter, int member);
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ssize_t res_counter_read(struct res_counter *counter, int member,
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const char __user *buf, size_t nbytes, loff_t *pos,
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int (*read_strategy)(unsigned long long val, char *s));
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int res_counter_memparse_write_strategy(const char *buf,
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unsigned long long *res);
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/*
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* the field descriptors. one for each member of res_counter
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*/
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enum {
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RES_USAGE,
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RES_MAX_USAGE,
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RES_LIMIT,
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RES_FAILCNT,
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RES_SOFT_LIMIT,
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};
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/*
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* helpers for accounting
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*/
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void res_counter_init(struct res_counter *counter, struct res_counter *parent);
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/*
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* charge - try to consume more resource.
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*
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* @counter: the counter
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* @val: the amount of the resource. each controller defines its own
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* units, e.g. numbers, bytes, Kbytes, etc
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*
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* returns 0 on success and <0 if the counter->usage will exceed the
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* counter->limit _locked call expects the counter->lock to be taken
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*
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* charge_nofail works the same, except that it charges the resource
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* counter unconditionally, and returns < 0 if the after the current
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* charge we are over limit.
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*/
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int __must_check res_counter_charge_locked(struct res_counter *counter,
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unsigned long val, bool force);
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int __must_check res_counter_charge(struct res_counter *counter,
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unsigned long val, struct res_counter **limit_fail_at);
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int res_counter_charge_nofail(struct res_counter *counter,
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unsigned long val, struct res_counter **limit_fail_at);
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/*
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* uncharge - tell that some portion of the resource is released
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*
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* @counter: the counter
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* @val: the amount of the resource
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*
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* these calls check for usage underflow and show a warning on the console
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* _locked call expects the counter->lock to be taken
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*
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* returns the total charges still present in @counter.
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*/
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u64 res_counter_uncharge_locked(struct res_counter *counter, unsigned long val);
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u64 res_counter_uncharge(struct res_counter *counter, unsigned long val);
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u64 res_counter_uncharge_until(struct res_counter *counter,
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struct res_counter *top,
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unsigned long val);
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/**
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* res_counter_margin - calculate chargeable space of a counter
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* @cnt: the counter
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*
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* Returns the difference between the hard limit and the current usage
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* of resource counter @cnt.
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*/
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static inline unsigned long long res_counter_margin(struct res_counter *cnt)
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{
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unsigned long long margin;
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unsigned long flags;
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spin_lock_irqsave(&cnt->lock, flags);
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if (cnt->limit > cnt->usage)
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margin = cnt->limit - cnt->usage;
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else
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margin = 0;
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spin_unlock_irqrestore(&cnt->lock, flags);
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return margin;
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}
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/**
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* Get the difference between the usage and the soft limit
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* @cnt: The counter
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*
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* Returns 0 if usage is less than or equal to soft limit
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* The difference between usage and soft limit, otherwise.
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*/
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static inline unsigned long long
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res_counter_soft_limit_excess(struct res_counter *cnt)
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{
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unsigned long long excess;
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unsigned long flags;
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spin_lock_irqsave(&cnt->lock, flags);
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if (cnt->usage <= cnt->soft_limit)
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excess = 0;
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else
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excess = cnt->usage - cnt->soft_limit;
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spin_unlock_irqrestore(&cnt->lock, flags);
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return excess;
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}
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static inline void res_counter_reset_max(struct res_counter *cnt)
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{
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unsigned long flags;
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spin_lock_irqsave(&cnt->lock, flags);
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cnt->max_usage = cnt->usage;
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spin_unlock_irqrestore(&cnt->lock, flags);
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}
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static inline void res_counter_reset_failcnt(struct res_counter *cnt)
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{
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unsigned long flags;
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spin_lock_irqsave(&cnt->lock, flags);
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cnt->failcnt = 0;
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spin_unlock_irqrestore(&cnt->lock, flags);
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}
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static inline int res_counter_set_limit(struct res_counter *cnt,
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unsigned long long limit)
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{
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unsigned long flags;
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int ret = -EBUSY;
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spin_lock_irqsave(&cnt->lock, flags);
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if (cnt->usage <= limit) {
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cnt->limit = limit;
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ret = 0;
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}
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spin_unlock_irqrestore(&cnt->lock, flags);
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return ret;
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}
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static inline int
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res_counter_set_soft_limit(struct res_counter *cnt,
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unsigned long long soft_limit)
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{
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unsigned long flags;
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spin_lock_irqsave(&cnt->lock, flags);
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cnt->soft_limit = soft_limit;
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spin_unlock_irqrestore(&cnt->lock, flags);
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return 0;
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}
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#endif
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