Commit e552b661 authored by Pavel Emelianov's avatar Pavel Emelianov Committed by Linus Torvalds

Memory controller: resource counters

With fixes from David Rientjes <rientjes@google.com>

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: default avatarPavel Emelianov <xemul@openvz.org>
Signed-off-by: default avatarBalbir Singh <balbir@linux.vnet.ibm.com>
Cc: Paul Menage <menage@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Signed-off-by: default avatarDavid Rientjes <rientjes@google.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 59bd2658
#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>
*
*/
#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 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
......@@ -369,6 +369,13 @@ config CGROUP_CPUACCT
Provides a simple Resource Controller for monitoring the
total CPU consumed by the tasks in a cgroup
config RESOURCE_COUNTERS
bool "Resource counters"
help
This option enables controller independent resource accounting
infrastructure that works with cgroups
depends on CGROUPS
config SYSFS_DEPRECATED
bool "Create deprecated sysfs files"
depends on SYSFS
......
......@@ -43,6 +43,7 @@ obj-$(CONFIG_CGROUP_DEBUG) += cgroup_debug.o
obj-$(CONFIG_CPUSETS) += cpuset.o
obj-$(CONFIG_CGROUP_NS) += ns_cgroup.o
obj-$(CONFIG_IKCONFIG) += configs.o
obj-$(CONFIG_RESOURCE_COUNTERS) += res_counter.o
obj-$(CONFIG_STOP_MACHINE) += stop_machine.o
obj-$(CONFIG_KPROBES_SANITY_TEST) += test_kprobes.o
obj-$(CONFIG_AUDIT) += audit.o auditfilter.o
......
/*
* resource cgroups
*
* Copyright 2007 OpenVZ SWsoft Inc
*
* Author: Pavel Emelianov <xemul@openvz.org>
*
*/
#include <linux/types.h>
#include <linux/parser.h>
#include <linux/fs.h>
#include <linux/res_counter.h>
#include <linux/uaccess.h>
void res_counter_init(struct res_counter *counter)
{
spin_lock_init(&counter->lock);
counter->limit = (unsigned long)LONG_MAX;
}
int res_counter_charge_locked(struct res_counter *counter, unsigned long val)
{
if (counter->usage + val > counter->limit) {
counter->failcnt++;
return -ENOMEM;
}
counter->usage += val;
return 0;
}
int res_counter_charge(struct res_counter *counter, unsigned long val)
{
int ret;
unsigned long flags;
spin_lock_irqsave(&counter->lock, flags);
ret = res_counter_charge_locked(counter, val);
spin_unlock_irqrestore(&counter->lock, flags);
return ret;
}
void res_counter_uncharge_locked(struct res_counter *counter, unsigned long val)
{
if (WARN_ON(counter->usage < val))
val = counter->usage;
counter->usage -= val;
}
void res_counter_uncharge(struct res_counter *counter, unsigned long val)
{
unsigned long flags;
spin_lock_irqsave(&counter->lock, flags);
res_counter_uncharge_locked(counter, val);
spin_unlock_irqrestore(&counter->lock, flags);
}
static inline unsigned long *res_counter_member(struct res_counter *counter,
int member)
{
switch (member) {
case RES_USAGE:
return &counter->usage;
case RES_LIMIT:
return &counter->limit;
case RES_FAILCNT:
return &counter->failcnt;
};
BUG();
return NULL;
}
ssize_t res_counter_read(struct res_counter *counter, int member,
const char __user *userbuf, size_t nbytes, loff_t *pos)
{
unsigned long *val;
char buf[64], *s;
s = buf;
val = res_counter_member(counter, member);
s += sprintf(s, "%lu\n", *val);
return simple_read_from_buffer((void __user *)userbuf, nbytes,
pos, buf, s - buf);
}
ssize_t res_counter_write(struct res_counter *counter, int member,
const char __user *userbuf, size_t nbytes, loff_t *pos)
{
int ret;
char *buf, *end;
unsigned long tmp, *val;
buf = kmalloc(nbytes + 1, GFP_KERNEL);
ret = -ENOMEM;
if (buf == NULL)
goto out;
buf[nbytes] = '\0';
ret = -EFAULT;
if (copy_from_user(buf, userbuf, nbytes))
goto out_free;
ret = -EINVAL;
tmp = simple_strtoul(buf, &end, 10);
if (*end != '\0')
goto out_free;
val = res_counter_member(counter, member);
*val = tmp;
ret = nbytes;
out_free:
kfree(buf);
out:
return ret;
}
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