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authorJosef Bacik <josef@toxicpanda.com>2018-09-28 13:45:39 -0400
committerJens Axboe <axboe@kernel.dk>2018-09-28 11:47:27 -0600
commitff4cee0898756f07f8b50b30ea00efc773de24e6 (patch)
tree0dc060c58f8cba542a16b007647d09adde272d7b
parentf0a0cdddb14c7a32e7ca68f45fbc44aa347e959d (diff)
downloadlinux-ff4cee0898756f07f8b50b30ea00efc773de24e6.tar.bz2
blk-iolatency: use q->nr_requests directly
We were using blk_queue_depth() assuming that it would return nr_requests, but we hit a case in production on drives that had to have NCQ turned off in order for them to not shit the bed which resulted in a qd of 1, even though the nr_requests was much larger. iolatency really only cares about requests we are allowed to queue up, as any io that get's onto the request list is going to be serviced soonish, so we want to be throttling before the bio gets onto the request list. To make iolatency work as expected, simply use q->nr_requests instead of blk_queue_depth() as that is what we actually care about. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
-rw-r--r--block/blk-iolatency.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c
index 27c14f8d2576..c2e38bc12f27 100644
--- a/block/blk-iolatency.c
+++ b/block/blk-iolatency.c
@@ -255,7 +255,7 @@ static void scale_cookie_change(struct blk_iolatency *blkiolat,
struct child_latency_info *lat_info,
bool up)
{
- unsigned long qd = blk_queue_depth(blkiolat->rqos.q);
+ unsigned long qd = blkiolat->rqos.q->nr_requests;
unsigned long scale = scale_amount(qd, up);
unsigned long old = atomic_read(&lat_info->scale_cookie);
unsigned long max_scale = qd << 1;
@@ -295,7 +295,7 @@ static void scale_cookie_change(struct blk_iolatency *blkiolat,
*/
static void scale_change(struct iolatency_grp *iolat, bool up)
{
- unsigned long qd = blk_queue_depth(iolat->blkiolat->rqos.q);
+ unsigned long qd = iolat->blkiolat->rqos.q->nr_requests;
unsigned long scale = scale_amount(qd, up);
unsigned long old = iolat->rq_depth.max_depth;
@@ -857,7 +857,7 @@ static void iolatency_pd_init(struct blkg_policy_data *pd)
rq_wait_init(&iolat->rq_wait);
spin_lock_init(&iolat->child_lat.lock);
- iolat->rq_depth.queue_depth = blk_queue_depth(blkg->q);
+ iolat->rq_depth.queue_depth = blkg->q->nr_requests;
iolat->rq_depth.max_depth = UINT_MAX;
iolat->rq_depth.default_depth = iolat->rq_depth.queue_depth;
iolat->blkiolat = blkiolat;