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| author | Jens Axboe <axboe@suse.de> | 2005-10-20 16:42:29 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@nelson.home.kernel.dk> | 2005-10-28 08:45:08 +0200 |
| commit | b4878f245ec8e168cdd1f170f823a750b7dd4af5 (patch) | |
| tree | de784c2a7e1174e4843807998f0356bf92ee78be /drivers/block/noop-iosched.c | |
| parent | d9ebb192aa13a026edc6faff137dcb14f2c91731 (diff) | |
| download | linux-b4878f245ec8e168cdd1f170f823a750b7dd4af5.tar.gz | |
[PATCH] 02/05: update ioscheds to use generic dispatch queue
This patch updates all four ioscheds to use generic dispatch
queue. There's one behavior change in as-iosched.
* In as-iosched, when force dispatching
(ELEVATOR_INSERT_BACK), batch_data_dir is reset to REQ_SYNC
and changed_batch and new_batch are cleared to zero. This
prevernts AS from doing incorrect update_write_batch after
the forced dispatched requests are finished.
* In cfq-iosched, cfqd->rq_in_driver currently counts the
number of activated (removed) requests to determine
whether queue-kicking is needed and cfq_max_depth has been
reached. With generic dispatch queue, I think counting
the number of dispatched requests would be more appropriate.
* cfq_max_depth can be lowered to 1 again.
Original from Tejun Heo, modified version applied.
Signed-off-by: Jens Axboe <axboe@suse.de>
Diffstat (limited to 'drivers/block/noop-iosched.c')
| -rw-r--r-- | drivers/block/noop-iosched.c | 17 |
1 files changed, 5 insertions, 12 deletions
diff --git a/drivers/block/noop-iosched.c b/drivers/block/noop-iosched.c index b1730b62c37e4..bc2252b6f2e5f 100644 --- a/drivers/block/noop-iosched.c +++ b/drivers/block/noop-iosched.c @@ -28,13 +28,9 @@ static void elevator_noop_merge_requests(request_queue_t *q, struct request *req list_del_init(&next->queuelist); } -static void elevator_noop_add_request(request_queue_t *q, struct request *rq, - int where) +static void elevator_noop_add_request(request_queue_t *q, struct request *rq) { - if (where == ELEVATOR_INSERT_FRONT) - list_add(&rq->queuelist, &q->queue_head); - else - list_add_tail(&rq->queuelist, &q->queue_head); + elv_dispatch_add_tail(q, rq); /* * new merges must not precede this barrier @@ -45,19 +41,16 @@ static void elevator_noop_add_request(request_queue_t *q, struct request *rq, q->last_merge = rq; } -static struct request *elevator_noop_next_request(request_queue_t *q) +static int elevator_noop_dispatch(request_queue_t *q, int force) { - if (!list_empty(&q->queue_head)) - return list_entry_rq(q->queue_head.next); - - return NULL; + return 0; } static struct elevator_type elevator_noop = { .ops = { .elevator_merge_fn = elevator_noop_merge, .elevator_merge_req_fn = elevator_noop_merge_requests, - .elevator_next_req_fn = elevator_noop_next_request, + .elevator_dispatch_fn = elevator_noop_dispatch, .elevator_add_req_fn = elevator_noop_add_request, }, .elevator_name = "noop", |