diff options
| author | Jens Axboe <axboe@suse.de> | 2006-07-19 20:29:12 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@nelson.home.kernel.dk> | 2006-09-30 20:29:41 +0200 |
| commit | bf57225670bcbeb357182d800736b4782cde7295 (patch) | |
| tree | c86d71fefff36090fc5c2ea3694f95d0162cdc2c | |
| parent | [PATCH] Add blk_start_queueing() helper (diff) | |
| download | linux-bf57225670bcbeb357182d800736b4782cde7295.tar.xz linux-bf57225670bcbeb357182d800736b4782cde7295.zip | |
[PATCH] cfq-iosched: improve queue preemption
Don't touch the current queues, just make sure that the wanted queue
is selected next. Simplifies the logic.
Signed-off-by: Jens Axboe <axboe@suse.de>
| -rw-r--r-- | block/cfq-iosched.c | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 9f684cc66bd1..141104835952 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -1539,17 +1539,19 @@ cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq, */ static void cfq_preempt_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq) { - struct cfq_queue *__cfqq, *next; - - list_for_each_entry_safe(__cfqq, next, &cfqd->cur_rr, cfq_list) - cfq_resort_rr_list(__cfqq, 1); + cfq_slice_expired(cfqd, 1); if (!cfqq->slice_left) cfqq->slice_left = cfq_prio_to_slice(cfqd, cfqq) / 2; + /* + * Put the new queue at the front of the of the current list, + * so we know that it will be selected next. + */ + BUG_ON(!cfq_cfqq_on_rr(cfqq)); + list_move(&cfqq->cfq_list, &cfqd->cur_rr); + cfqq->slice_end = cfqq->slice_left + jiffies; - cfq_slice_expired(cfqd, 1); - __cfq_set_active_queue(cfqd, cfqq); } /* |