From: Kanchan Joshi <joshi.k@samsung.com>
To: Daniel Wagner <dwagner@suse.de>
Cc: Ming Lei <ming.lei@redhat.com>, Sagi Grimberg <sagi@grimberg.me>,
Jens Axboe <axboe@kernel.dk>,
hch@lst.de, kbusch@kernel.org, io-uring@vger.kernel.org,
linux-nvme@lists.infradead.org, linux-block@vger.kernel.org,
asml.silence@gmail.com, joshiiitr@gmail.com,
anuj20.g@samsung.com, gost.dev@samsung.com
Subject: Re: [PATCH for-next 3/4] io_uring: grow a field in struct io_uring_cmd
Date: Fri, 15 Jul 2022 16:37:00 +0530 [thread overview]
Message-ID: <20220715110700.GA27117@test-zns> (raw)
In-Reply-To: <20220714153051.5e53zgkcabb7ajms@carbon.lan>
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On Thu, Jul 14, 2022 at 05:30:51PM +0200, Daniel Wagner wrote:
>On Thu, Jul 14, 2022 at 01:49:23PM +0530, Kanchan Joshi wrote:
>> If path is not available, retry is not done immediately rather we wait for
>> path to be available (as underlying controller may still be
>> resetting/connecting). List helped as command gets added into
>> it (and submitter/io_uring gets the control back), and retry is done
>> exact point in time.
>> But yes, it won't harm if we do couple of retries even if path is known
>> not to be available (somewhat like iopoll). As this situation is
>> not common. And with that scheme, we don't have to link io_uring_cmd.
>
>Stupid question does it only fail over immediately when the path is not
>available or any failure? If it fails over for everything it's possible
>the target gets the same request twice. FWIW, we are just debugging this
>scenario right now.
failover is only for path-related failure, and not otherwise.
you might want to take a look at nvme_decide_disposition routine where
it makes that decision.
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next prev parent reply other threads:[~2022-07-15 11:12 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20220711110753epcas5p4169b9e288d15ca35740dbb66a6f6983a@epcas5p4.samsung.com>
2022-07-11 11:01 ` [PATCH for-next 0/4] nvme-multipathing for uring-passthrough Kanchan Joshi
2022-07-11 11:01 ` [PATCH for-next 1/4] io_uring, nvme: rename a function Kanchan Joshi
2022-07-14 13:55 ` Ming Lei
2022-07-11 11:01 ` [PATCH for-next 2/4] nvme: compact nvme_uring_cmd_pdu struct Kanchan Joshi
2022-07-12 6:32 ` Christoph Hellwig
2022-07-11 11:01 ` [PATCH for-next 3/4] io_uring: grow a field in struct io_uring_cmd Kanchan Joshi
2022-07-11 17:00 ` Sagi Grimberg
2022-07-11 17:19 ` Jens Axboe
2022-07-11 17:18 ` Jens Axboe
2022-07-11 17:55 ` Sagi Grimberg
2022-07-11 18:22 ` Sagi Grimberg
2022-07-11 18:24 ` Jens Axboe
2022-07-11 18:58 ` Sagi Grimberg
2022-07-12 11:40 ` Kanchan Joshi
2022-07-14 3:40 ` Ming Lei
2022-07-14 8:19 ` Kanchan Joshi
2022-07-14 15:30 ` Daniel Wagner
2022-07-15 11:07 ` Kanchan Joshi [this message]
2022-07-18 9:03 ` Daniel Wagner
2022-07-11 11:01 ` [PATCH for-next 4/4] nvme-multipath: add multipathing for uring-passthrough commands Kanchan Joshi
2022-07-11 13:51 ` Sagi Grimberg
2022-07-11 15:12 ` Stefan Metzmacher
2022-07-11 16:58 ` Sagi Grimberg
2022-07-11 18:54 ` Kanchan Joshi
2022-07-11 18:37 ` Kanchan Joshi
2022-07-11 19:56 ` Sagi Grimberg
2022-07-12 4:23 ` Kanchan Joshi
2022-07-12 21:26 ` Sagi Grimberg
2022-07-13 5:37 ` Kanchan Joshi
2022-07-13 9:03 ` Sagi Grimberg
2022-07-13 11:28 ` Kanchan Joshi
2022-07-13 12:17 ` Sagi Grimberg
2022-07-14 15:14 ` Ming Lei
2022-07-14 23:05 ` Kanchan Joshi
2022-07-15 1:35 ` Ming Lei
2022-07-15 1:46 ` Ming Lei
2022-07-15 4:24 ` Kanchan Joshi
2022-07-12 6:52 ` Christoph Hellwig
2022-07-12 11:33 ` Kanchan Joshi
2022-07-12 20:13 ` Sagi Grimberg
2022-07-13 5:36 ` Christoph Hellwig
2022-07-13 8:04 ` Sagi Grimberg
2022-07-13 10:12 ` Christoph Hellwig
2022-07-13 11:00 ` Sagi Grimberg
2022-07-13 11:28 ` Christoph Hellwig
2022-07-13 12:16 ` Sagi Grimberg
2022-07-13 11:49 ` Hannes Reinecke
2022-07-13 12:43 ` Sagi Grimberg
2022-07-13 13:30 ` Hannes Reinecke
2022-07-13 13:41 ` Sagi Grimberg
2022-07-13 14:07 ` Hannes Reinecke
2022-07-13 15:59 ` Sagi Grimberg
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