diff options
Diffstat (limited to 'block/bfq-iosched.c')
| -rw-r--r-- | block/bfq-iosched.c | 29 |
1 files changed, 19 insertions, 10 deletions
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index ccdc9e6b5df1..509f39998011 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -3114,7 +3114,10 @@ static bool bfq_may_expire_for_budg_timeout(struct bfq_queue *bfqq) static bool bfq_bfqq_may_idle(struct bfq_queue *bfqq) { struct bfq_data *bfqd = bfqq->bfqd; - bool idling_boosts_thr, idling_boosts_thr_without_issues, + bool rot_without_queueing = + !blk_queue_nonrot(bfqd->queue) && !bfqd->hw_tag, + bfqq_sequential_and_IO_bound, + idling_boosts_thr, idling_boosts_thr_without_issues, idling_needed_for_service_guarantees, asymmetric_scenario; @@ -3133,28 +3136,34 @@ static bool bfq_bfqq_may_idle(struct bfq_queue *bfqq) bfq_class_idle(bfqq)) return false; + bfqq_sequential_and_IO_bound = !BFQQ_SEEKY(bfqq) && + bfq_bfqq_IO_bound(bfqq) && bfq_bfqq_has_short_ttime(bfqq); + /* * The next variable takes into account the cases where idling * boosts the throughput. * * The value of the variable is computed considering, first, that * idling is virtually always beneficial for the throughput if: - * (a) the device is not NCQ-capable, or - * (b) regardless of the presence of NCQ, the device is rotational - * and the request pattern for bfqq is I/O-bound and sequential. + * (a) the device is not NCQ-capable and rotational, or + * (b) regardless of the presence of NCQ, the device is rotational and + * the request pattern for bfqq is I/O-bound and sequential, or + * (c) regardless of whether it is rotational, the device is + * not NCQ-capable and the request pattern for bfqq is + * I/O-bound and sequential. * * Secondly, and in contrast to the above item (b), idling an * NCQ-capable flash-based device would not boost the * throughput even with sequential I/O; rather it would lower * the throughput in proportion to how fast the device * is. Accordingly, the next variable is true if any of the - * above conditions (a) and (b) is true, and, in particular, - * happens to be false if bfqd is an NCQ-capable flash-based - * device. + * above conditions (a), (b) or (c) is true, and, in + * particular, happens to be false if bfqd is an NCQ-capable + * flash-based device. */ - idling_boosts_thr = !bfqd->hw_tag || - (!blk_queue_nonrot(bfqd->queue) && bfq_bfqq_IO_bound(bfqq) && - bfq_bfqq_has_short_ttime(bfqq)); + idling_boosts_thr = rot_without_queueing || + ((!blk_queue_nonrot(bfqd->queue) || !bfqd->hw_tag) && + bfqq_sequential_and_IO_bound); /* * The value of the next variable, |