diff options
Diffstat (limited to 'block')
| -rw-r--r-- | block/blk-iocost.c | 2 | ||||
| -rw-r--r-- | block/blk-mq-sched.c | 22 | ||||
| -rw-r--r-- | block/genhd.c | 36 |
3 files changed, 59 insertions, 1 deletions
diff --git a/block/blk-iocost.c b/block/blk-iocost.c index 6a7788f31c22..db35ee682294 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -1315,7 +1315,7 @@ static bool iocg_is_idle(struct ioc_gq *iocg) return false; /* is something in flight? */ - if (atomic64_read(&iocg->done_vtime) < atomic64_read(&iocg->vtime)) + if (atomic64_read(&iocg->done_vtime) != atomic64_read(&iocg->vtime)) return false; return true; diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c index 856356b1619e..74cedea56034 100644 --- a/block/blk-mq-sched.c +++ b/block/blk-mq-sched.c @@ -398,6 +398,28 @@ void blk_mq_sched_insert_request(struct request *rq, bool at_head, WARN_ON(e && (rq->tag != -1)); if (blk_mq_sched_bypass_insert(hctx, !!e, rq)) { + /* + * Firstly normal IO request is inserted to scheduler queue or + * sw queue, meantime we add flush request to dispatch queue( + * hctx->dispatch) directly and there is at most one in-flight + * flush request for each hw queue, so it doesn't matter to add + * flush request to tail or front of the dispatch queue. + * + * Secondly in case of NCQ, flush request belongs to non-NCQ + * command, and queueing it will fail when there is any + * in-flight normal IO request(NCQ command). When adding flush + * rq to the front of hctx->dispatch, it is easier to introduce + * extra time to flush rq's latency because of S_SCHED_RESTART + * compared with adding to the tail of dispatch queue, then + * chance of flush merge is increased, and less flush requests + * will be issued to controller. It is observed that ~10% time + * is saved in blktests block/004 on disk attached to AHCI/NCQ + * drive when adding flush rq to the front of hctx->dispatch. + * + * Simply queue flush rq to the front of hctx->dispatch so that + * intensive flush workloads can benefit in case of NCQ HW. + */ + at_head = (rq->rq_flags & RQF_FLUSH_SEQ) ? true : at_head; blk_mq_request_bypass_insert(rq, at_head, false); goto run; } diff --git a/block/genhd.c b/block/genhd.c index 14cf395a1479..06b642b23a07 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -373,6 +373,42 @@ struct hd_struct *disk_map_sector_rcu(struct gendisk *disk, sector_t sector) return &disk->part0; } +/** + * disk_has_partitions + * @disk: gendisk of interest + * + * Walk through the partition table and check if valid partition exists. + * + * CONTEXT: + * Don't care. + * + * RETURNS: + * True if the gendisk has at least one valid non-zero size partition. + * Otherwise false. + */ +bool disk_has_partitions(struct gendisk *disk) +{ + struct disk_part_tbl *ptbl; + int i; + bool ret = false; + + rcu_read_lock(); + ptbl = rcu_dereference(disk->part_tbl); + + /* Iterate partitions skipping the whole device at index 0 */ + for (i = 1; i < ptbl->len; i++) { + if (rcu_dereference(ptbl->part[i])) { + ret = true; + break; + } + } + + rcu_read_unlock(); + + return ret; +} +EXPORT_SYMBOL_GPL(disk_has_partitions); + /* * Can be deleted altogether. Later. * |