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[linux-2.6.git] / include / linux / elevator.h

diff --git a/include/linux/elevator.h b/include/linux/elevator.h
index 8cf0e3f..27e8183 100644 (file)
--- a/include/linux/elevator.h
+++ b/include/linux/elevator.h
@@ -22,9 +22,9 @@ typedef int (elevator_set_req_fn) (request_queue_t *, struct request *, int);
 typedef void (elevator_put_req_fn) (request_queue_t *, struct request *);
 
 typedef int (elevator_init_fn) (request_queue_t *, elevator_t *);
-typedef void (elevator_exit_fn) (elevator_t *);
+typedef void (elevator_exit_fn) (request_queue_t *, elevator_t *);
 
-struct elevator_ops
+struct elevator_s
 {
        elevator_merge_fn *elevator_merge_fn;
        elevator_merged_fn *elevator_merged_fn;
@@ -48,32 +48,12 @@ struct elevator_ops
 
        elevator_init_fn *elevator_init_fn;
        elevator_exit_fn *elevator_exit_fn;
-};
-
-#define ELV_NAME_MAX   (16)
-
-/*
- * identifies an elevator type, such as AS or deadline
- */
-struct elevator_type
-{
-       struct list_head list;
-       struct elevator_ops ops;
-       struct elevator_type *elevator_type;
-       struct kobj_type *elevator_ktype;
-       char elevator_name[ELV_NAME_MAX];
-       struct module *elevator_owner;
-};
 
-/*
- * each queue has an elevator_queue assoicated with it
- */
-struct elevator_queue
-{
-       struct elevator_ops *ops;
        void *elevator_data;
+
        struct kobject kobj;
-       struct elevator_type *elevator_type;
+       struct kobj_type *elevator_ktype;
+       const char *elevator_name;
 };
 
 /*
@@ -99,19 +79,28 @@ extern int elv_set_request(request_queue_t *, struct request *, int);
 extern void elv_put_request(request_queue_t *, struct request *);
 
 /*
- * io scheduler registration
+ * noop I/O scheduler. always merges, always inserts new request at tail
+ */
+extern elevator_t elevator_noop;
+
+/*
+ * deadline i/o scheduler. uses request time outs to prevent indefinite
+ * starvation
  */
-extern int elv_register(struct elevator_type *);
-extern void elv_unregister(struct elevator_type *);
+extern elevator_t iosched_deadline;
 
 /*
- * io scheduler sysfs switching
+ * anticipatory I/O scheduler
  */
-extern ssize_t elv_iosched_show(request_queue_t *, char *);
-extern ssize_t elv_iosched_store(request_queue_t *, const char *, size_t);
+extern elevator_t iosched_as;
 
-extern int elevator_init(request_queue_t *, char *);
-extern void elevator_exit(elevator_t *);
+/*
+ * completely fair queueing I/O scheduler
+ */
+extern elevator_t iosched_cfq;
+
+extern int elevator_init(request_queue_t *, elevator_t *);
+extern void elevator_exit(request_queue_t *);
 extern int elv_rq_merge_ok(struct request *, struct bio *);
 extern int elv_try_merge(struct request *, struct bio *);
 extern int elv_try_last_merge(request_queue_t *, struct bio *);
@@ -130,13 +119,4 @@ extern int elv_try_last_merge(request_queue_t *, struct bio *);
 #define ELEVATOR_INSERT_BACK   2
 #define ELEVATOR_INSERT_SORT   3
 
-/*
- * return values from elevator_may_queue_fn
- */
-enum {
-       ELV_MQUEUE_MAY,
-       ELV_MQUEUE_NO,
-       ELV_MQUEUE_MUST,
-};
-
 #endif