linux/kernel/res_counter.c
Pavel Emelyanov c84872e168 memcgroup: add the max_usage member on the res_counter
This field is the maximal value of the usage one since the counter creation
(or since the latest reset).

To reset this to the usage value simply write anything to the appropriate
cgroup file.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Balbir Singh <balbir@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>
2008-04-29 08:06:10 -07:00

146 lines
3.1 KiB
C

/*
* 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/slab.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)LLONG_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;
if (counter->usage > counter->max_usage)
counter->max_usage = counter->usage;
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 long *
res_counter_member(struct res_counter *counter, int member)
{
switch (member) {
case RES_USAGE:
return &counter->usage;
case RES_MAX_USAGE:
return &counter->max_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,
int (*read_strategy)(unsigned long long val, char *st_buf))
{
unsigned long long *val;
char buf[64], *s;
s = buf;
val = res_counter_member(counter, member);
if (read_strategy)
s += read_strategy(*val, s);
else
s += sprintf(s, "%llu\n", *val);
return simple_read_from_buffer((void __user *)userbuf, nbytes,
pos, buf, s - buf);
}
u64 res_counter_read_u64(struct res_counter *counter, int member)
{
return *res_counter_member(counter, member);
}
ssize_t res_counter_write(struct res_counter *counter, int member,
const char __user *userbuf, size_t nbytes, loff_t *pos,
int (*write_strategy)(char *st_buf, unsigned long long *val))
{
int ret;
char *buf, *end;
unsigned long flags;
unsigned long 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;
strstrip(buf);
if (write_strategy) {
if (write_strategy(buf, &tmp)) {
goto out_free;
}
} else {
tmp = simple_strtoull(buf, &end, 10);
if (*end != '\0')
goto out_free;
}
spin_lock_irqsave(&counter->lock, flags);
val = res_counter_member(counter, member);
*val = tmp;
spin_unlock_irqrestore(&counter->lock, flags);
ret = nbytes;
out_free:
kfree(buf);
out:
return ret;
}