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authorSamuel Thibault <samuel.thibault@ens-lyon.org>2013-07-27 22:15:01 +0000
committerSamuel Thibault <samuel.thibault@ens-lyon.org>2013-07-27 22:15:01 +0000
commit7996a3d79d55b7f879dfd62e202bbfe2963718d3 (patch)
tree8d9f6759fec4099b9be503c11c7ed174f7204980 /libdde-linux26/contrib/include/linux/res_counter.h
parent4fbe7358c7747a9165f776eb19addbb9baf7def2 (diff)
really properly move files
Diffstat (limited to 'libdde-linux26/contrib/include/linux/res_counter.h')
-rw-r--r--libdde-linux26/contrib/include/linux/res_counter.h181
1 files changed, 181 insertions, 0 deletions
diff --git a/libdde-linux26/contrib/include/linux/res_counter.h b/libdde-linux26/contrib/include/linux/res_counter.h
new file mode 100644
index 00000000..4c5bcf6c
--- /dev/null
+++ b/libdde-linux26/contrib/include/linux/res_counter.h
@@ -0,0 +1,181 @@
+#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>
+ *
+ * See Documentation/cgroups/resource_counter.txt for more
+ * info about what this counter is.
+ */
+
+#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 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 long limit;
+ /*
+ * the number of unsuccessful attempts to consume the resource
+ */
+ 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;
+};
+
+/**
+ * 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
+ *
+ * @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.
+ */
+
+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));
+
+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,
+};
+
+/*
+ * helpers for accounting
+ */
+
+void res_counter_init(struct res_counter *counter, struct res_counter *parent);
+
+/*
+ * 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 __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
+ *
+ * @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);
+
+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);
+}
+
+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