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From: Kanchan Joshi <[email protected]>
To: Keith Busch <[email protected]>,
	[email protected], [email protected],
	[email protected]
Cc: [email protected], [email protected], [email protected],
	Keith Busch <[email protected]>
Subject: Re: [PATCH 2/4] nvme: use bio_integrity_map_user
Date: Wed, 25 Oct 2023 18:56:58 +0530	[thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>

On 10/18/2023 8:48 PM, Keith Busch wrote:
> From: Keith Busch <[email protected]>
> 
> Map user metadata buffers directly instead of maintaining a complicated
> copy buffer.
> 
> Now that the bio tracks the metadata through its bip, nvme doesn't need
> special metadata handling, callbacks, or additional fields in the pdu.
> This greatly simplifies passthrough handling and avoids a "might_fault"
> copy_to_user in the completion path. This also creates pdu space to
> track the original request separately from its bio, further simplifying
> polling without relying on special iouring fields.
> 
> The downside is that nvme requires the metadata buffer be physically
> contiguous, so user space will need to utilize huge pages if the buffer
> needs to span multiple pages.

I did not notice where this downside part is getting checked in the code.

  parent reply	other threads:[~2023-10-25 13:27 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-10-18 15:18 [PATCH 0/4] block integrity: direclty map user space addresses Keith Busch
2023-10-18 15:18 ` [PATCH 1/4] block: bio-integrity: add support for user buffers Keith Busch
2023-10-19  5:39   ` Christoph Hellwig
2023-10-21  3:53   ` kernel test robot
2023-10-21  4:13   ` kernel test robot
2023-10-25 12:51   ` Kanchan Joshi
2023-10-25 14:42     ` Keith Busch
2023-10-18 15:18 ` [PATCH 2/4] nvme: use bio_integrity_map_user Keith Busch
2023-10-19  5:40   ` Christoph Hellwig
2023-10-25 13:26   ` Kanchan Joshi [this message]
2023-10-18 15:18 ` [PATCH 3/4] iouring: remove IORING_URING_CMD_POLLED Keith Busch
2023-10-19  5:41   ` Christoph Hellwig
2023-10-19 14:43     ` Keith Busch
2023-10-23  6:18   ` Kanchan Joshi
2023-10-18 15:18 ` [PATCH 4/4] io_uring: remove uring_cmd cookie Keith Busch
2023-10-19  5:34 ` [PATCH 0/4] block integrity: direclty map user space addresses Christoph Hellwig

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