| Message ID | 20230219104309.1511562-3-shikemeng@huaweicloud.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Some bugfix and cleanup patches for bfq | expand |
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index 3f5c740664ce..4868538c9745 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -1768,6 +1768,10 @@ static bool bfq_bfqq_higher_class_or_weight(struct bfq_queue *bfqq, if (bfqq->ioprio_class < in_serv_bfqq->ioprio_class) return true; + /* only try weight comparison with same priority class */ + if (bfqq->ioprio_class != in_serv_bfqq->ioprio_class) + return false; + if (in_serv_bfqq->entity.parent == bfqq->entity.parent) { bfqq_weight = bfqq->entity.weight; in_serv_weight = in_serv_bfqq->entity.weight;
We will compare priority class and weight of current bfqq with in_service_queue to check if bfqq could preempt in_service_queue. Currently we will try to preempt in_service_queue if bfqq has higher weight than in_service_queue even with lower priority class. Actually, we will only serve bfqq with higher priority class (see bfq_lookup_next_entity), so bfqq with higher weight and lower priority class will not be a candidate to preempt in_service_queue. Compare weight of bfqqs with the same priority in bfq_bfqq_higher_class_or_weight to make preemption check more reasonable. Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> --- block/bfq-iosched.c | 4 ++++ 1 file changed, 4 insertions(+)