From: Bart Van Assche <Bart.VanAssche@sandisk.com>
To: "hch@infradead.org" <hch@infradead.org>,
"linux-block@vger.kernel.org" <linux-block@vger.kernel.org>,
"axboe@fb.com" <axboe@fb.com>,
"ming.lei@redhat.com" <ming.lei@redhat.com>
Subject: Re: [PATCH v3 5/9] blk-mq: fix blk_mq_quiesce_queue
Date: Wed, 31 May 2017 15:37:30 +0000 [thread overview]
Message-ID: <1496245049.2608.7.camel@sandisk.com> (raw)
In-Reply-To: <20170531123706.20885-6-ming.lei@redhat.com>
On Wed, 2017-05-31 at 20:37 +0800, Ming Lei wrote:
>=20
> + /* wait until queue is unquiesced */
> + wait_event_cmd(q->quiesce_wq, !blk_queue_quiesced(q),
> + may_sleep ?
> + srcu_read_unlock(&hctx->queue_rq_srcu, *srcu_idx) :
> + rcu_read_unlock(),
> + may_sleep ?
> + *srcu_idx =3D srcu_read_lock(&hctx->queue_rq_srcu) :
> + rcu_read_lock());
> +
> if (q->elevator)
> goto insert;
What I see is that in this patch a new waitqueue has been introduced
(quiesce_wq) and also that an explanation of why you think this new waitque=
ue
is needed is missing completely. Why is it that you think that the
synchronize_scru() and synchronize_rcu() calls in blk_mq_quiesce_queue() ar=
e
not sufficient? If this new waitqueue is not needed, please remove that
waitqueue again.
Bart.=
next prev parent reply other threads:[~2017-05-31 15:37 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-31 12:36 [PATCH v3 0/8] blk-mq: fix & improve queue quiescing Ming Lei
2017-05-31 12:36 ` [PATCH v3 1/9] blk-mq: introduce blk_mq_unquiesce_queue Ming Lei
2017-05-31 12:36 ` [PATCH v3 2/9] block: introduce flag of QUEUE_FLAG_QUIESCED Ming Lei
2017-05-31 12:37 ` [PATCH v3 3/9] blk-mq: use the introduced blk_mq_unquiesce_queue() Ming Lei
2017-05-31 15:21 ` Bart Van Assche
2017-06-01 0:54 ` Ming Lei
2017-06-01 23:09 ` Bart Van Assche
2017-06-02 2:00 ` Ming Lei
2017-06-02 22:19 ` Bart Van Assche
2017-05-31 12:37 ` [PATCH v3 4/9] nvme: host: unquiesce queue in nvme_kill_queues() Ming Lei
2017-05-31 12:37 ` [PATCH v3 5/9] blk-mq: fix blk_mq_quiesce_queue Ming Lei
2017-05-31 15:37 ` Bart Van Assche [this message]
2017-06-01 2:21 ` Ming Lei
2017-06-01 23:19 ` Bart Van Assche
2017-06-02 2:02 ` Ming Lei
2017-05-31 12:37 ` [PATCH v3 6/9] blk-mq: update comments on blk_mq_quiesce_queue() Ming Lei
2017-05-31 12:37 ` [PATCH v3 7/9] blk-mq: don't stop queue for quiescing Ming Lei
2017-05-31 12:37 ` [PATCH v3 8/9] blk-mq: clarify dispatch may not be drained/blocked by stopping queue Ming Lei
2017-05-31 12:37 ` [PATCH v3 9/9] Revert "blk-mq: don't use sync workqueue flushing from drivers" Ming Lei
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