From 9817064b68fef7e4580c6df1ea597e106b9ff88b Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Fri, 28 Jul 2006 09:23:08 +0200 Subject: [PATCH] elevator: move the backmerging logic into the elevator core Right now, every IO scheduler implements its own backmerging (except for noop, which does no merging). That results in duplicated code for essentially the same operation, which is never a good thing. This patch moves the backmerging out of the io schedulers and into the elevator core. We save 1.6kb of text and as a bonus get backmerging for noop as well. Win-win! Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 17 ++--------------- include/linux/elevator.h | 2 ++ 2 files changed, 4 insertions(+), 15 deletions(-) (limited to 'include') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index b2a412cf468..8f548696467 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -229,6 +229,8 @@ struct request { struct bio *bio; struct bio *biotail; + struct hlist_node hash; /* merge hash */ + void *elevator_private; void *completion_data; @@ -696,21 +698,6 @@ static inline void blkdev_dequeue_request(struct request *req) elv_dequeue_request(req->q, req); } -/* - * This should be in elevator.h, but that requires pulling in rq and q - */ -static inline void elv_dispatch_add_tail(struct request_queue *q, - struct request *rq) -{ - if (q->last_merge == rq) - q->last_merge = NULL; - q->nr_sorted--; - - q->end_sector = rq_end_sector(rq); - q->boundary_rq = rq; - list_add_tail(&rq->queuelist, &q->queue_head); -} - /* * Access functions for manipulating queue properties */ diff --git a/include/linux/elevator.h b/include/linux/elevator.h index 1713ace808b..2c270e90b33 100644 --- a/include/linux/elevator.h +++ b/include/linux/elevator.h @@ -82,12 +82,14 @@ struct elevator_queue struct kobject kobj; struct elevator_type *elevator_type; struct mutex sysfs_lock; + struct hlist_head *hash; }; /* * block elevator interface */ extern void elv_dispatch_sort(request_queue_t *, struct request *); +extern void elv_dispatch_add_tail(request_queue_t *, struct request *); 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); -- cgit v1.2.3-70-g09d2