在 2022/12/20 上午5:22, Tejun Heo 写道:
Hello, This looks generally fine to me. Some nits below.+static inline struct bio *throtl_qnode_bio_peek(struct throtl_qnode *qn) +{ + struct bio *bio1, *bio2; + + /* qn for read ios */ + if (qn->dispatch_sync_cnt == UINT_MAX) + return bio_list_peek(&qn->bios[SYNC]); + + /* qn for write ios */ + bio1 = bio_list_peek(&qn->bios[SYNC]); + bio2 = bio_list_peek(&qn->bios[ASYNC]); + + if (bio1 && bio2) { + if (qn->dispatch_sync_cnt == THROTL_SYNC_FACTOR) + return bio2; + return bio1; + } + + return bio1 ?: bio2; +}Wouldn't it be simpler to write: if (qn->dispatch_sync_count < THROTL_SYNC_FACTOR) return bio1 ?: bio2; else return bio2 ?: bio1;+/** + * throtl_qnode_bio_pop: pop a bio from a qnode + * @qn: the qnode to pop a bio from + * + * For read io qn, just pop bio from sync queu and return. + * For write io qn, the target queue to pop was determined by the dispatch_sync_cnt. + * Try to pop bio from target queue, fetch the bio and return when it is not empty. + * If the target queue empty, pop bio from other queue instead. + */ +static inline struct bio *throtl_qnode_bio_pop(struct throtl_qnode *qn) +{ + struct bio *bio; + + /* qn for read ios */ + if (qn->dispatch_sync_cnt == UINT_MAX) + return bio_list_pop(&qn->bios[SYNC]); + + /* try to dispatch sync io */ + if (qn->dispatch_sync_cnt < THROTL_SYNC_FACTOR) { + bio = bio_list_pop(&qn->bios[SYNC]); + if (bio) { + qn->dispatch_sync_cnt++; + return bio; + } + bio = bio_list_pop(&qn->bios[ASYNC]); + qn->dispatch_sync_cnt = 0; + return bio; + } + + /* try to dispatch async io */ + bio = bio_list_pop(&qn->bios[ASYNC]); + if (bio) { + qn->dispatch_sync_cnt = 0; + return bio; + } + bio = bio_list_pop(&qn->bios[SYNC]); + + return bio; +}This also seems like it can be simplified a bit. Thanks.
Indeed, I will make it more clear and send the v2. Thanks.
