diff options
Diffstat (limited to 'block/blk-iocost.c')
| -rw-r--r-- | block/blk-iocost.c | 25 |
1 files changed, 18 insertions, 7 deletions
diff --git a/block/blk-iocost.c b/block/blk-iocost.c index cffed980dfac..e72e562d4aad 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -1784,28 +1784,39 @@ static void ioc_rqos_merge(struct rq_qos *rqos, struct request *rq, struct bio *bio) { struct ioc_gq *iocg = blkg_to_iocg(bio->bi_blkg); + struct ioc *ioc = iocg->ioc; sector_t bio_end = bio_end_sector(bio); + struct ioc_now now; u32 hw_inuse; u64 abs_cost, cost; - /* add iff the existing request has cost assigned */ - if (!rq->bio || !rq->bio->bi_iocost_cost) + /* bypass if disabled or for root cgroup */ + if (!ioc->enabled || !iocg->level) return; abs_cost = calc_vtime_cost(bio, iocg, true); if (!abs_cost) return; + ioc_now(ioc, &now); + current_hweight(iocg, NULL, &hw_inuse); + cost = abs_cost_to_cost(abs_cost, hw_inuse); + /* update cursor if backmerging into the request at the cursor */ if (blk_rq_pos(rq) < bio_end && blk_rq_pos(rq) + blk_rq_sectors(rq) == iocg->cursor) iocg->cursor = bio_end; - current_hweight(iocg, NULL, &hw_inuse); - cost = div64_u64(abs_cost * HWEIGHT_WHOLE, hw_inuse); - bio->bi_iocost_cost = cost; - - atomic64_add(cost, &iocg->vtime); + /* + * Charge if there's enough vtime budget and the existing request + * has cost assigned. Otherwise, account it as debt. See debt + * handling in ioc_rqos_throttle() for details. + */ + if (rq->bio && rq->bio->bi_iocost_cost && + time_before_eq64(atomic64_read(&iocg->vtime) + cost, now.vnow)) + iocg_commit_bio(iocg, bio, cost); + else + atomic64_add(abs_cost, &iocg->abs_vdebt); } static void ioc_rqos_done_bio(struct rq_qos *rqos, struct bio *bio) |