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![Balbir Singh](/assets/img/avatar_default.png)
Add support for building hierarchies in resource counters. Cgroups allows us to build a deep hierarchy, but we currently don't link the resource counters belonging to the memory controller control groups, in the same fashion as the corresponding cgroup entries in the cgroup hierarchy. This patch provides the infrastructure for resource counters that have the same hiearchy as their cgroup counter parts. These set of patches are based on the resource counter hiearchy patches posted by Pavel Emelianov. NOTE: Building hiearchies is expensive, deeper hierarchies imply charging the all the way up to the root. It is known that hiearchies are expensive, so the user needs to be careful and aware of the trade-offs before creating very deep ones. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp> Cc: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: Pavel Emelianov <xemul@openvz.org> Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
181 lines
4.5 KiB
C
181 lines
4.5 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/controllers/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/cgroup.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 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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/**
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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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typedef int (*write_strategy_fn)(const char *buf, unsigned long long *val);
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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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int res_counter_write(struct res_counter *counter, int member,
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const char *buffer, write_strategy_fn write_strategy);
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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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};
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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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int __must_check res_counter_charge_locked(struct res_counter *counter,
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unsigned long val);
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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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/*
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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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void res_counter_uncharge_locked(struct res_counter *counter, unsigned long val);
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void res_counter_uncharge(struct res_counter *counter, unsigned long val);
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static inline bool res_counter_limit_check_locked(struct res_counter *cnt)
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{
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if (cnt->usage < cnt->limit)
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return true;
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return false;
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}
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/*
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* Helper function to detect if the cgroup is within it's limit or
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* not. It's currently called from cgroup_rss_prepare()
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*/
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static inline bool res_counter_check_under_limit(struct res_counter *cnt)
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{
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bool ret;
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unsigned long flags;
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spin_lock_irqsave(&cnt->lock, flags);
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ret = res_counter_limit_check_locked(cnt);
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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 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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#endif
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