+#include <linux/idr.h>
+#include <linux/rwsem.h>
+#include <linux/notifier.h>
+
+/*
+ * ipc namespace events
+ */
+#define IPCNS_MEMCHANGED 0x00000001 /* Notify lowmem size changed */
+#define IPCNS_CREATED 0x00000002 /* Notify new ipc namespace created */
+#define IPCNS_REMOVED 0x00000003 /* Notify ipc namespace removed */
+
+#define IPCNS_CALLBACK_PRI 0
+
+
+struct ipc_ids {
+ int in_use;
+ unsigned short seq;
+ unsigned short seq_max;
+ struct rw_semaphore rw_mutex;
+ struct idr ipcs_idr;
+};