From 0bb979472a7401022109e81dd89d777adea58710 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Wed, 10 Jun 2015 08:01:20 -0600 Subject: cfq-iosched: fix the setting of IOPS mode on SSDs A previous commit wanted to make CFQ default to IOPS mode on non-rotational storage, however it did so when the queue was initialized and the non-rotational flag is only set later on in the probe. Add an elevator hook that gets called off the add_disk() path, at that point we know that feature probing has finished, and we can reliably check for the various flags that drivers can set. Fixes: 41c0126b ("block: Make CFQ default to IOPS mode on SSDs") Tested-by: Romain Francoise Signed-off-by: Jens Axboe --- block/cfq-iosched.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) (limited to 'block/cfq-iosched.c') diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index c808ad87652d..d1d0cb235cd2 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -4508,7 +4508,7 @@ static int cfq_init_queue(struct request_queue *q, struct elevator_type *e) cfqd->cfq_slice[1] = cfq_slice_sync; cfqd->cfq_target_latency = cfq_target_latency; cfqd->cfq_slice_async_rq = cfq_slice_async_rq; - cfqd->cfq_slice_idle = blk_queue_nonrot(q) ? 0 : cfq_slice_idle; + cfqd->cfq_slice_idle = cfq_slice_idle; cfqd->cfq_group_idle = cfq_group_idle; cfqd->cfq_latency = 1; cfqd->hw_tag = -1; @@ -4525,6 +4525,18 @@ out_free: return ret; } +static void cfq_registered_queue(struct request_queue *q) +{ + struct elevator_queue *e = q->elevator; + struct cfq_data *cfqd = e->elevator_data; + + /* + * Default to IOPS mode with no idling for SSDs + */ + if (blk_queue_nonrot(q)) + cfqd->cfq_slice_idle = 0; +} + /* * sysfs parts below --> */ @@ -4640,6 +4652,7 @@ static struct elevator_type iosched_cfq = { .elevator_may_queue_fn = cfq_may_queue, .elevator_init_fn = cfq_init_queue, .elevator_exit_fn = cfq_exit_queue, + .elevator_registered_fn = cfq_registered_queue, }, .icq_size = sizeof(struct cfq_io_cq), .icq_align = __alignof__(struct cfq_io_cq), -- cgit v1.2.3