diff options
author | Jens Axboe <axboe@suse.de> | 2006-06-13 06:08:38 (GMT) |
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committer | Jens Axboe <axboe@nelson.home.kernel.dk> | 2006-06-23 15:10:38 (GMT) |
commit | 271f18f102c789f59644bb6c53a69da1df72b2f4 (patch) | |
tree | f3593b5dbc90da69a91a69fb170c2600775703f7 /block/cfq-iosched.c | |
parent | acf421755593f7d7bd9352d57eda796c6eb4fa43 (diff) | |
download | linux-fsl-qoriq-271f18f102c789f59644bb6c53a69da1df72b2f4.tar.xz |
[PATCH] cfq-iosched: Don't set the queue batching limits
We cannot update them if the user changes nr_requests, so don't
set it in the first place. The gains are pretty questionable as
well. The batching loss has been shown to decrease throughput.
Signed-off-by: Jens Axboe <axboe@suse.de>
Diffstat (limited to 'block/cfq-iosched.c')
-rw-r--r-- | block/cfq-iosched.c | 48 |
1 files changed, 3 insertions, 45 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index e2e6ad0..c88f161d 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -123,8 +123,6 @@ struct cfq_data { */ struct hlist_head *crq_hash; - unsigned int max_queued; - mempool_t *crq_pool; int rq_in_driver; @@ -1910,7 +1908,6 @@ static inline int __cfq_may_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq, struct task_struct *task, int rw) { -#if 1 if ((cfq_cfqq_wait_request(cfqq) || cfq_cfqq_must_alloc(cfqq)) && !cfq_cfqq_must_alloc_slice(cfqq)) { cfq_mark_cfqq_must_alloc_slice(cfqq); @@ -1918,39 +1915,6 @@ __cfq_may_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq, } return ELV_MQUEUE_MAY; -#else - if (!cfqq || task->flags & PF_MEMALLOC) - return ELV_MQUEUE_MAY; - if (!cfqq->allocated[rw] || cfq_cfqq_must_alloc(cfqq)) { - if (cfq_cfqq_wait_request(cfqq)) - return ELV_MQUEUE_MUST; - - /* - * only allow 1 ELV_MQUEUE_MUST per slice, otherwise we - * can quickly flood the queue with writes from a single task - */ - if (rw == READ || !cfq_cfqq_must_alloc_slice(cfqq)) { - cfq_mark_cfqq_must_alloc_slice(cfqq); - return ELV_MQUEUE_MUST; - } - - return ELV_MQUEUE_MAY; - } - if (cfq_class_idle(cfqq)) - return ELV_MQUEUE_NO; - if (cfqq->allocated[rw] >= cfqd->max_queued) { - struct io_context *ioc = get_io_context(GFP_ATOMIC); - int ret = ELV_MQUEUE_NO; - - if (ioc && ioc->nr_batch_requests) - ret = ELV_MQUEUE_MAY; - - put_io_context(ioc); - return ret; - } - - return ELV_MQUEUE_MAY; -#endif } static int cfq_may_queue(request_queue_t *q, int rw, struct bio *bio) @@ -1979,16 +1943,13 @@ static int cfq_may_queue(request_queue_t *q, int rw, struct bio *bio) static void cfq_check_waiters(request_queue_t *q, struct cfq_queue *cfqq) { struct cfq_data *cfqd = q->elevator->elevator_data; - struct request_list *rl = &q->rq; - if (cfqq->allocated[READ] <= cfqd->max_queued || cfqd->rq_starved) { + if (unlikely(cfqd->rq_starved)) { + struct request_list *rl = &q->rq; + smp_mb(); if (waitqueue_active(&rl->wait[READ])) wake_up(&rl->wait[READ]); - } - - if (cfqq->allocated[WRITE] <= cfqd->max_queued || cfqd->rq_starved) { - smp_mb(); if (waitqueue_active(&rl->wait[WRITE])) wake_up(&rl->wait[WRITE]); } @@ -2278,9 +2239,6 @@ static void *cfq_init_queue(request_queue_t *q, elevator_t *e) cfqd->queue = q; - cfqd->max_queued = q->nr_requests / 4; - q->nr_batching = cfq_queued; - init_timer(&cfqd->idle_slice_timer); cfqd->idle_slice_timer.function = cfq_idle_slice_timer; cfqd->idle_slice_timer.data = (unsigned long) cfqd; |