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authorPavel Emelianov <xemul@openvz.org>2008-02-07 00:13:49 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2008-02-07 08:42:18 -0800
commite552b6617067ab785256dcec5ca29eeea981aacb (patch)
tree672cccc2e21abfa4dcdc1bdb198e748894bbbbc6 /include/linux/res_counter.h
parent59bd26582de660d4c9c26125747f1b4a5eb40d1e (diff)
Memory controller: resource counters
With fixes from David Rientjes <rientjes@google.com> Introduce generic structures and routines for resource accounting. Each resource accounting cgroup is supposed to aggregate it, cgroup_subsystem_state and its resource-specific members within. Signed-off-by: Pavel Emelianov <xemul@openvz.org> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Kirill Korotaev <dev@sw.ru> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Signed-off-by: David Rientjes <rientjes@google.com> Cc: Pavel Emelianov <xemul@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/res_counter.h')
-rw-r--r--include/linux/res_counter.h102
1 files changed, 102 insertions, 0 deletions
diff --git a/include/linux/res_counter.h b/include/linux/res_counter.h
new file mode 100644
index 000000000000..eeb3f7749772
--- /dev/null
+++ b/include/linux/res_counter.h
@@ -0,0 +1,102 @@
+#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>
+ *
+ */
+
+#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 usage;
+ /*
+ * the limit that usage cannot exceed
+ */
+ unsigned long limit;
+ /*
+ * the number of unsuccessful attempts to consume the resource
+ */
+ unsigned 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/_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.
+ */
+
+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);
+
+/*
+ * the field descriptors. one for each member of res_counter
+ */
+
+enum {
+ RES_USAGE,
+ RES_LIMIT,
+ RES_FAILCNT,
+};
+
+/*
+ * helpers for accounting
+ */
+
+void res_counter_init(struct res_counter *counter);
+
+/*
+ * 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 res_counter_charge_locked(struct res_counter *counter, unsigned long val);
+int res_counter_charge(struct res_counter *counter, unsigned long val);
+
+/*
+ * 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);
+
+#endif