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From: Sagi Grimberg <[email protected]>
To: Kanchan Joshi <[email protected]>
Cc: [email protected], [email protected], [email protected],
	[email protected], [email protected],
	[email protected], [email protected],
	[email protected], [email protected], [email protected]
Subject: Re: [PATCH for-next 4/4] nvme-multipath: add multipathing for uring-passthrough commands
Date: Wed, 13 Jul 2022 12:03:48 +0300	[thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <20220713053757.GA15022@test-zns>


>> However io_kiocb is less
>> constrained, and could be used as a context to hold such a space.
>>
>> Even if it is undesired to have io_kiocb be passed to uring_cmd(), it
>> can still hold a driver specific space paired with a helper to obtain it
>> (i.e. something like io_uring_cmd_to_driver_ctx(ioucmd) ). Then if the
>> space is pre-allocated it is only a small memory copy for a stable copy
>> that would allow a saner failover design.
> 
> I am thinking along the same lines, but it's not about few bytes of
> space rather we need 80 (72 to be precise). Will think more, but
> these 72 bytes really stand tall in front of my optimism.

You don't have to populate this space on every I/O, you can just
populate it when there is no usable path and when you failover a
request...

  reply	other threads:[~2022-07-13  9:04 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
     [not found]   ` <CGME20220711110800epcas5p3d338dd486fd778c5ba5bfe93a91ec8bd@epcas5p3.samsung.com>
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
     [not found]   ` <CGME20220711110812epcas5p33aa90b23aa62fb11722aa8195754becf@epcas5p3.samsung.com>
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
     [not found]   ` <CGME20220711110824epcas5p22c8e945cb8c3c3ac46c8c2b5ab55db9b@epcas5p2.samsung.com>
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
2022-07-18  9:03                     ` Daniel Wagner
     [not found]   ` <CGME20220711110827epcas5p3fd81f142f55ca3048abc38a9ef0d0089@epcas5p3.samsung.com>
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 [this message]
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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