From: Chunguang Xu <[email protected]> CLASS_RT is more sensitive to latency, and IO injection will increase the CLASS_RT latency. For this reason, consider prohibiting the injection of async queue for CLASS_RT, and only the waker queue and other active queues belonging to CLASS_RT are allowed to inject. In this way, for CLASS_RT, both the advantages of inject and IO latency can be maintained.
Signed-off-by: Chunguang Xu <[email protected]> --- block/bfq-iosched.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index 8af73473c45c..a5f13589df79 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -1965,6 +1965,9 @@ static void bfq_check_waker(struct bfq_data *bfqd, struct bfq_queue *bfqq, bfqd->last_completed_rq_bfqq == bfqq->waker_bfqq) return; + if (bfq_class_rt(bfqq) && !bfq_class_rt(bfqd->last_completed_rq_bfqq)) + return; + if (bfqd->last_completed_rq_bfqq != bfqq->tentative_waker_bfqq) { /* @@ -4391,6 +4394,9 @@ bfq_choose_bfqq_for_injection(struct bfq_data *bfqd) else limit = in_serv_bfqq->inject_limit; + if (bfq_class_rt(in_serv_bfqq) && !bfq_class_rt(bfqq)) + continue; + if (bfqd->rq_in_driver < limit) { bfqd->rqs_injected = true; return bfqq; @@ -4565,7 +4571,7 @@ static struct bfq_queue *bfq_select_queue(struct bfq_data *bfqd) * may not be minimized, because the waker queue may * happen to be served only after other queues. */ - if (async_bfqq && + if (async_bfqq && !bfq_class_rt(bfqq) && icq_to_bic(async_bfqq->next_rq->elv.icq) == bfqq->bic && bfq_serv_to_charge(async_bfqq->next_rq, async_bfqq) <= bfq_bfqq_budget_left(async_bfqq)) -- 2.30.0
