*
* 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 usage;
+ 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
*/
- unsigned long limit;
+ unsigned long long limit;
/*
* the number of unsuccessful attempts to consume the resource
*/
- unsigned long failcnt;
+ unsigned long 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_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);
+ 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);
+ const char __user *buf, size_t nbytes, loff_t *pos,
+ int (*write_strategy)(char *buf, unsigned long long *val));
/*
* the field descriptors. one for each member of res_counter
enum {
RES_USAGE,
+ RES_MAX_USAGE,
RES_LIMIT,
RES_FAILCNT,
};
void res_counter_uncharge_locked(struct res_counter *counter, unsigned long val);
void res_counter_uncharge(struct res_counter *counter, unsigned long val);
+static inline bool res_counter_limit_check_locked(struct res_counter *cnt)
+{
+ if (cnt->usage < cnt->limit)
+ return true;
+
+ return false;
+}
+
+/*
+ * Helper function to detect if the cgroup is within it's limit or
+ * not. It's currently called from cgroup_rss_prepare()
+ */
+static inline bool res_counter_check_under_limit(struct res_counter *cnt)
+{
+ bool ret;
+ unsigned long flags;
+
+ spin_lock_irqsave(&cnt->lock, flags);
+ ret = res_counter_limit_check_locked(cnt);
+ spin_unlock_irqrestore(&cnt->lock, flags);
+ 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);
+}
#endif