From e552b6617067ab785256dcec5ca29eeea981aacb Mon Sep 17 00:00:00 2001 From: Pavel Emelianov Date: Thu, 7 Feb 2008 00:13:49 -0800 Subject: Memory controller: resource counters With fixes from David Rientjes Introduce generic structures and routines for resource accounting. Each resource accounting cgroup is supposed to aggregate it, cgroup_subsystem_state and its resource-specific members within. Signed-off-by: Pavel Emelianov Signed-off-by: Balbir Singh Cc: Paul Menage Cc: Peter Zijlstra Cc: "Eric W. Biederman" Cc: Nick Piggin Cc: Kirill Korotaev Cc: Herbert Poetzl Cc: Vaidyanathan Srinivasan Signed-off-by: David Rientjes Cc: Pavel Emelianov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/res_counter.h | 102 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 102 insertions(+) create mode 100644 include/linux/res_counter.h (limited to 'include/linux/res_counter.h') diff --git a/include/linux/res_counter.h b/include/linux/res_counter.h new file mode 100644 index 0000000..eeb3f77 --- /dev/null +++ b/include/linux/res_counter.h @@ -0,0 +1,102 @@ +#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 + * + */ + +#include + +/* + * 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 usage; + /* + * the limit that usage cannot exceed + */ + unsigned long limit; + /* + * the number of unsuccessful attempts to consume the resource + */ + unsigned 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/_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. + */ + +ssize_t res_counter_read(struct res_counter *counter, int member, + const char __user *buf, size_t nbytes, loff_t *pos); +ssize_t res_counter_write(struct res_counter *counter, int member, + const char __user *buf, size_t nbytes, loff_t *pos); + +/* + * the field descriptors. one for each member of res_counter + */ + +enum { + RES_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 res_counter_charge_locked(struct res_counter *counter, unsigned long val); +int 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); + +#endif -- cgit v1.1