From: Ming Lei <tom.leiming@gmail.com>
To: Jianchao Wang <jianchao.w.wang@oracle.com>
Cc: Jens Axboe <axboe@kernel.dk>,
Bart Van Assche <bart.vanassche@wdc.com>,
Keith Busch <keith.busch@linux.intel.com>,
linux-block <linux-block@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 2/2] blk-mq: sync the update nr_hw_queues with part_in_flight
Date: Thu, 16 Aug 2018 12:50:31 +0800 [thread overview]
Message-ID: <CACVXFVO+g2ACx9XYx4XtwRkpSC9bCYeSFEj07Z==6r7nT-HxkQ@mail.gmail.com> (raw)
In-Reply-To: <1534317915-5041-3-git-send-email-jianchao.w.wang@oracle.com>
On Wed, Aug 15, 2018 at 3:25 PM, Jianchao Wang
<jianchao.w.wang@oracle.com> wrote:
> For blk-mq, part_in_flight/rw will invoke blk_mq_in_flight/rw to
> account the inflight requests. It will access the queue_hw_ctx and
> nr_hw_queues w/o any protection. When updating nr_hw_queues and
> blk_mq_in_flight/rw occur concurrently, panic comes up.
When updating nr_hw_queues, all queues are frozen, and there shouldn't
be any inflight requests, so there shouldn't be such issue.
Thanks,
Ming Lei
next prev parent reply other threads:[~2018-08-16 4:50 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-15 7:25 [PATCH 0/2] fixes for the updating nr_hw_queues Jianchao Wang
2018-08-15 7:25 ` [PATCH 1/2] blk-mq: init hctx sched after update cpu & nr_hw_queues mapping Jianchao Wang
2018-08-15 11:32 ` Ming Lei
2018-08-16 9:52 ` jianchao.wang
2018-08-15 7:25 ` [PATCH 2/2] blk-mq: sync the update nr_hw_queues with part_in_flight Jianchao Wang
2018-08-16 4:50 ` Ming Lei [this message]
2018-08-16 8:29 ` jianchao.wang
2018-08-16 9:03 ` Ming Lei
2018-08-16 9:20 ` jianchao.wang
2018-08-16 9:38 ` Ming Lei
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