From: "jianchao.wang" <jianchao.w.wang@oracle.com>
To: Tejun Heo <tj@kernel.org>
Cc: axboe@kernel.dk, linux-kernel@vger.kernel.org, oleg@redhat.com,
peterz@infradead.org, kernel-team@fb.com, osandov@fb.com
Subject: Re: [PATCH 6/6] blk-mq: remove REQ_ATOM_STARTED
Date: Thu, 14 Dec 2017 10:14:31 +0800 [thread overview]
Message-ID: <da74ba78-852a-84e5-89a1-d238302d8aef@oracle.com> (raw)
In-Reply-To: <20171213160913.GR3919388@devbig577.frc2.facebook.com>
On 12/14/2017 12:09 AM, Tejun Heo wrote:
> Hello,
>
> On Wed, Dec 13, 2017 at 11:05:11AM +0800, jianchao.wang wrote:
>> Just don't quite understand the strict definition of "generation" you said.
>> A allocation->free cycle is a generation ? or a idle->in-flight cycle is a
>> generation? The idle->in-flight cycle could include the requeue case as above.
>> Can you clarify this?
>
> So, a request is
>
> * IN_FLIGHT, if it can be completed by the lower level driver
>
> * COMPLETE, if the lower level driver indicated completion but block
> layer is still processing.
>
> * IDLE, if neither of the above two.
>
> and generation is bumped up on IDLE -> IN_FLIGHT to distinguish
> different IN_FLIGHT instances.
>
So a generation means a cycle from IDLE -> IN_FLIGHT.
Thanks for your response. That's really appreciated.
Jianchao
> Thanks.
>
next prev parent reply other threads:[~2017-12-14 2:14 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-09 19:25 [PATCHSET] blk-mq: reimplement timeout handling Tejun Heo
2017-12-09 19:25 ` [PATCH 1/6] blk-mq: protect completion path with RCU Tejun Heo
2017-12-13 3:10 ` jianchao.wang
2017-12-09 19:25 ` [PATCH 2/6] blk-mq: replace timeout synchronization with a RCU and generation based scheme Tejun Heo
2017-12-12 10:09 ` Peter Zijlstra
2017-12-12 18:02 ` Tejun Heo
2017-12-12 10:10 ` Peter Zijlstra
2017-12-12 18:03 ` Tejun Heo
2017-12-12 11:56 ` Peter Zijlstra
2017-12-12 18:04 ` Tejun Heo
2017-12-09 19:25 ` [PATCH 3/6] blk-mq: use blk_mq_rq_state() instead of testing REQ_ATOM_COMPLETE Tejun Heo
2017-12-09 19:25 ` [PATCH 4/6] blk-mq: make blk_abort_request() trigger timeout path Tejun Heo
2017-12-09 19:25 ` [PATCH 5/6] blk-mq: remove REQ_ATOM_COMPLETE usages from blk-mq Tejun Heo
2017-12-09 19:25 ` [PATCH 6/6] blk-mq: remove REQ_ATOM_STARTED Tejun Heo
2017-12-12 10:09 ` jianchao.wang
2017-12-12 17:01 ` Tejun Heo
2017-12-12 17:26 ` Tejun Heo
2017-12-13 3:05 ` jianchao.wang
2017-12-13 16:09 ` Tejun Heo
2017-12-14 2:14 ` jianchao.wang [this message]
2017-12-12 11:17 ` Nikolay Borisov
2017-12-12 17:29 ` Tejun Heo
2017-12-11 9:27 ` [PATCHSET] blk-mq: reimplement timeout handling Peter Zijlstra
2017-12-12 9:21 ` Christoph Hellwig
2017-12-12 16:39 ` Tejun Heo
2017-12-12 16:08 ` Peter Zijlstra
2017-12-12 19:01 [PATCHSET v2] " Tejun Heo
2017-12-12 19:01 ` [PATCH 6/6] blk-mq: remove REQ_ATOM_STARTED Tejun Heo
2017-12-12 22:20 ` Bart Van Assche
2017-12-12 22:22 ` tj
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