*
* Author: Pavel Emelianov <xemul@openvz.org>
*
+ * See Documentation/cgroups/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 limit that usage can be exceed
+ */
+ unsigned long long soft_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;
+ /*
+ * Parent counter, used for hierarchial resource accounting
+ */
+ struct res_counter *parent;
};
-/*
+#define RESOURCE_MAX (unsigned long long)LLONG_MAX
+
+/**
* 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);
-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 (*read_strategy)(unsigned long long val, char *s));
+
+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,
+ RES_SOFT_LIMIT,
};
/*
* helpers for accounting
*/
-void res_counter_init(struct res_counter *counter);
+void res_counter_init(struct res_counter *counter, struct res_counter *parent);
/*
* charge - try to consume more resource.
* 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, struct res_counter **limit_fail_at);
/*
* uncharge - tell that some portion of the resource is released
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;
+}
+
+static inline bool res_counter_soft_limit_check_locked(struct res_counter *cnt)
+{
+ if (cnt->usage < cnt->soft_limit)
+ return true;
+
+ return false;
+}
+
+/**
+ * Get the difference between the usage and the soft limit
+ * @cnt: The counter
+ *
+ * Returns 0 if usage is less than or equal to soft limit
+ * The difference between usage and soft limit, otherwise.
+ */
+static inline unsigned long long
+res_counter_soft_limit_excess(struct res_counter *cnt)
+{
+ unsigned long long excess;
+ unsigned long flags;
+
+ spin_lock_irqsave(&cnt->lock, flags);
+ if (cnt->usage <= cnt->soft_limit)
+ excess = 0;
+ else
+ excess = cnt->usage - cnt->soft_limit;
+ spin_unlock_irqrestore(&cnt->lock, flags);
+ return excess;
+}
+
+/*
+ * 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 bool res_counter_check_under_soft_limit(struct res_counter *cnt)
+{
+ bool ret;
+ unsigned long flags;
+
+ spin_lock_irqsave(&cnt->lock, flags);
+ ret = res_counter_soft_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);
+}
+
+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;
+}
+
+static inline int
+res_counter_set_soft_limit(struct res_counter *cnt,
+ unsigned long long soft_limit)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&cnt->lock, flags);
+ cnt->soft_limit = soft_limit;
+ spin_unlock_irqrestore(&cnt->lock, flags);
+ return 0;
+}
+
#endif
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff