[PATCH 5/7] iosched: introduce elv_kick_page()

[Fengguang Wu <wfg@mail.ustc.edu.cn>]

[-- Attachment #1: iosched-kick-page-elevator.patch --]
[-- Type: text/plain, Size: 2416 bytes --]

Introduce elv_kick_page() to turn a possibly READA request into READ.
The underlying elevator_kick_page_fn() should also reschedule the request
if necessary.

Signed-off-by: Wu Fengguang <wfg@mail.ustc.edu.cn>
---


 block/ll_rw_blk.c        |    8 ++++++++
 fs/buffer.c              |    5 +++--
 include/linux/elevator.h |    2 ++
 3 files changed, 13 insertions(+), 2 deletions(-)

--- linux-2.6.17-rc5-mm3.orig/include/linux/elevator.h
+++ linux-2.6.17-rc5-mm3/include/linux/elevator.h
@@ -20,6 +20,7 @@ typedef int (elevator_set_req_fn) (reque
 typedef void (elevator_put_req_fn) (request_queue_t *, struct request *);
 typedef void (elevator_activate_req_fn) (request_queue_t *, struct request *);
 typedef void (elevator_deactivate_req_fn) (request_queue_t *, struct request *);
+typedef int (elevator_kick_page_fn) (request_queue_t *, struct page *);
 
 typedef int (elevator_init_fn) (request_queue_t *, elevator_t *);
 typedef void (elevator_exit_fn) (elevator_t *);
@@ -34,6 +35,7 @@ struct elevator_ops
 	elevator_add_req_fn *elevator_add_req_fn;
 	elevator_activate_req_fn *elevator_activate_req_fn;
 	elevator_deactivate_req_fn *elevator_deactivate_req_fn;
+	elevator_kick_page_fn *elevator_kick_page_fn;
 
 	elevator_queue_empty_fn *elevator_queue_empty_fn;
 	elevator_completed_req_fn *elevator_completed_req_fn;
@@ -91,6 +93,7 @@ extern void elv_dispatch_sort(request_qu
 extern void elv_add_request(request_queue_t *, struct request *, int, int);
 extern void __elv_add_request(request_queue_t *, struct request *, int, int);
 extern void elv_insert(request_queue_t *, struct request *, int);
+extern void elv_kick_page(request_queue_t *, struct page *);
 extern int elv_merge(request_queue_t *, struct request **, struct bio *);
 extern void elv_merge_requests(request_queue_t *, struct request *,
 			       struct request *);
--- linux-2.6.17-rc5-mm3.orig/block/elevator.c
+++ linux-2.6.17-rc5-mm3/block/elevator.c
@@ -468,6 +468,16 @@ void elv_add_request(request_queue_t *q,
 	spin_unlock_irqrestore(q->queue_lock, flags);
 }
 
+void elv_kick_page(request_queue_t *q, struct page *page)
+{
+	if (page && q->elevator && q->elevator->ops->elevator_kick_page_fn) {
+		spin_lock_irq(q->queue_lock);
+		q->elevator->ops->elevator_kick_page_fn(q, page);
+		spin_unlock_irq(q->queue_lock);
+	}
+
+}
+
 static inline struct request *__elv_next_request(request_queue_t *q)
 {
 	struct request *rq;

--