*
* Author: Pavel Emelianov <xemul@openvz.org>
*
+ * See Documentation/controllers/resource_counter.txt for more
+ * info about what this counter is.
*/
#include <linux/cgroup.h>
* the current resource consumption level
*/
unsigned long long usage;
+ /*
+ * the maximal value of the usage from the counter creation
+ */
+ unsigned long long max_usage;
/*
* the limit that usage cannot exceed
*/
spinlock_t lock;
};
-/*
+/**
* Helpers to interact with userspace
+ * res_counter_read_u64() - returns the value of the specified member.
* res_counter_read/_write - put/get the specified fields from the
* res_counter struct to/from the user
*
* @pos: and the offset.
*/
+u64 res_counter_read_u64(struct res_counter *counter, int member);
+
ssize_t res_counter_read(struct res_counter *counter, int member,
const char __user *buf, size_t nbytes, loff_t *pos,
int (*read_strategy)(unsigned long long val, char *s));
-ssize_t res_counter_write(struct res_counter *counter, int member,
- const char __user *buf, size_t nbytes, loff_t *pos,
- int (*write_strategy)(char *buf, unsigned long long *val));
+
+typedef int (*write_strategy_fn)(const char *buf, unsigned long long *val);
+
+int res_counter_memparse_write_strategy(const char *buf,
+ unsigned long long *res);
+
+int res_counter_write(struct res_counter *counter, int member,
+ const char *buffer, write_strategy_fn write_strategy);
/*
* the field descriptors. one for each member of res_counter
enum {
RES_USAGE,
+ RES_MAX_USAGE,
RES_LIMIT,
RES_FAILCNT,
};
* 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);
+int __must_check res_counter_charge_locked(struct res_counter *counter,
+ unsigned long val);
+int __must_check res_counter_charge(struct res_counter *counter,
+ unsigned long val);
/*
* uncharge - tell that some portion of the resource is released
return ret;
}
+static inline void res_counter_reset_max(struct res_counter *cnt)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&cnt->lock, flags);
+ cnt->max_usage = cnt->usage;
+ spin_unlock_irqrestore(&cnt->lock, flags);
+}
+
+static inline void res_counter_reset_failcnt(struct res_counter *cnt)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&cnt->lock, flags);
+ cnt->failcnt = 0;
+ spin_unlock_irqrestore(&cnt->lock, flags);
+}
+
+static inline int res_counter_set_limit(struct res_counter *cnt,
+ unsigned long long limit)
+{
+ unsigned long flags;
+ int ret = -EBUSY;
+
+ spin_lock_irqsave(&cnt->lock, flags);
+ if (cnt->usage < limit) {
+ cnt->limit = limit;
+ ret = 0;
+ }
+ spin_unlock_irqrestore(&cnt->lock, flags);
+ return ret;
+}
+
#endif