Messages in this thread | | | Subject | Re: [PATCH RFC 8/9] block, bfq: move forward __bfq_weights_tree_remove() | From | "yukuai (C)" <> | Date | Sat, 11 Dec 2021 10:18:53 +0800 |
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在 2021/12/10 18:00, Paolo Valente 写道: > > >> Il giorno 27 nov 2021, alle ore 11:11, Yu Kuai <yukuai3@huawei.com> ha scritto: >> >> Prepare to decrease 'num_groups_with_pending_reqs' earlier. >> >> Signed-off-by: Yu Kuai <yukuai3@huawei.com> >> --- >> block/bfq-iosched.c | 13 +++++-------- >> 1 file changed, 5 insertions(+), 8 deletions(-) >> >> diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c >> index e3c31db4bffb..4239b3996e23 100644 >> --- a/block/bfq-iosched.c >> +++ b/block/bfq-iosched.c >> @@ -882,6 +882,10 @@ void bfq_weights_tree_remove(struct bfq_data *bfqd, >> { >> struct bfq_entity *entity = bfqq->entity.parent; >> >> + bfqq->ref++; >> + __bfq_weights_tree_remove(bfqd, bfqq, >> + &bfqd->queue_weights_tree); >> + >> for_each_entity(entity) { >> struct bfq_sched_data *sd = entity->my_sched_data; >> >> @@ -916,14 +920,7 @@ void bfq_weights_tree_remove(struct bfq_data *bfqd, >> } >> } >> >> - /* >> - * Next function is invoked last, because it causes bfqq to be >> - * freed if the following holds: bfqq is not in service and >> - * has no dispatched request. DO NOT use bfqq after the next >> - * function invocation. >> - */ >> - __bfq_weights_tree_remove(bfqd, bfqq, >> - &bfqd->queue_weights_tree); >> + bfq_put_queue(bfqq); >> } >> > > why it is not dangerous any longer to invoke __bfq_weights_tree_remove earlier, and the comment can be removed?
Hi, Paolo
Here I grab an additional ref to the bfqq, thus the bfqq is ensured not to be free before bfq_put_queue() at the end of the function.
Maybe some comments is more appropriate.
Thanks, Kuai > > Paolo > >> /* >> -- >> 2.31.1 >> > > . >
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