On Fri 24-12-21 09:45:02, yukuai (C) wrote:
在 2021/12/24 1:31, Jan Kara 写道:
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index 056399185c2f..0da47f2ca781 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -2638,6 +2638,14 @@ bfq_setup_merge(struct bfq_queue *bfqq, struct bfq_queue *new_bfqq) if (process_refs == 0 || new_process_refs == 0) return NULL;
- /*
* Make sure merged queues belong to the same parent. Parents could* have changed since the time we decided the two queues are suitable* for merging.*/- if (new_bfqq->entity.parent != bfqq->entity.parent)
return NULL;Hi,
This seems unnecessary, the caller of bfq_setup_merge() aready make sure bfqq and new_bfqq are under the same bfqg. Am I missing something?
Not all the callers of bfq_setup_merge() check that queues belong to the same cgroup (e.g. bfq_setup_cooperator() does not seem to check).
Honza
Thanks, Kuai
bfq_log_bfqq(bfqq->bfqd, bfqq, "scheduling merge with queue %d", new_bfqq->pid);