From: Jens Axboe <[email protected]>
To: "Darrick J. Wong" <[email protected]>
Cc: [email protected], [email protected], [email protected],
[email protected], [email protected]
Subject: Re: [PATCH 5/8] iomap: only set iocb->private for polled bio
Date: Fri, 21 Jul 2023 09:37:20 -0600 [thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <20230721153515.GN11352@frogsfrogsfrogs>
On 7/21/23 9:35?AM, Darrick J. Wong wrote:
> On Thu, Jul 20, 2023 at 12:13:07PM -0600, Jens Axboe wrote:
>> iocb->private is only used for polled IO, where the completer will
>> find the bio to poll through that field.
>>
>> Assign it when we're submitting a polled bio, and get rid of the
>> dio->poll_bio indirection.
>
> IIRC, the only time iomap actually honors HIPRI requests from the iocb
> is if the entire write can be satisfied with a single bio -- no zeroing
> around, no dirty file metadata, no writes past EOF, no unwritten blocks,
> etc. Right?
>
> There was only ever going to be one assign to dio->submit.poll_bio,
> which means the WRITE_ONCE isn't going to overwrite some non-NULL value.
> Correct?
>
> All this does is remove the indirection like you said.
>
> If the answers are {yes, yes} then I understand the HIPRI mechanism
> enough to say
Correct, yes to both. For multi bio or not a straight overwrite, iomap
disables polling.
> Reviewed-by: Darrick J. Wong <[email protected]>
Thanks!
--
Jens Axboe
next prev parent reply other threads:[~2023-07-21 15:38 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-20 18:13 [PATCHSET v4 0/8] Improve async iomap DIO performance Jens Axboe
2023-07-20 18:13 ` [PATCH 1/8] iomap: cleanup up iomap_dio_bio_end_io() Jens Axboe
2023-07-21 6:14 ` Christoph Hellwig
2023-07-21 15:13 ` Darrick J. Wong
2023-07-20 18:13 ` [PATCH 2/8] iomap: add IOMAP_DIO_INLINE_COMP Jens Axboe
2023-07-21 6:14 ` Christoph Hellwig
2023-07-21 15:16 ` Darrick J. Wong
2023-07-20 18:13 ` [PATCH 3/8] iomap: treat a write through cache the same as FUA Jens Axboe
2023-07-21 6:15 ` Christoph Hellwig
2023-07-21 14:04 ` Jens Axboe
2023-07-21 15:55 ` Darrick J. Wong
2023-07-21 16:03 ` Jens Axboe
2023-07-20 18:13 ` [PATCH 4/8] iomap: completed polled IO inline Jens Axboe
2023-07-21 6:16 ` Christoph Hellwig
2023-07-21 15:19 ` Darrick J. Wong
2023-07-21 21:43 ` Dave Chinner
2023-07-22 3:10 ` Jens Axboe
2023-07-22 23:05 ` Dave Chinner
2023-07-24 22:35 ` Jens Axboe
2023-07-22 16:54 ` Jens Axboe
2023-07-20 18:13 ` [PATCH 5/8] iomap: only set iocb->private for polled bio Jens Axboe
2023-07-21 6:18 ` Christoph Hellwig
2023-07-21 15:35 ` Darrick J. Wong
2023-07-21 15:37 ` Jens Axboe [this message]
2023-07-20 18:13 ` [PATCH 6/8] fs: add IOCB flags related to passing back dio completions Jens Axboe
2023-07-21 6:18 ` Christoph Hellwig
2023-07-21 15:48 ` Darrick J. Wong
2023-07-21 15:53 ` Jens Axboe
2023-07-20 18:13 ` [PATCH 7/8] io_uring/rw: add write support for IOCB_DIO_DEFER Jens Axboe
2023-07-21 6:19 ` Christoph Hellwig
2023-07-21 15:50 ` Darrick J. Wong
2023-07-21 15:53 ` Jens Axboe
2023-07-20 18:13 ` [PATCH 8/8] iomap: support IOCB_DIO_DEFER Jens Axboe
2023-07-21 6:19 ` Christoph Hellwig
2023-07-21 16:01 ` Darrick J. Wong
2023-07-21 16:30 ` Jens Axboe
2023-07-21 22:05 ` Dave Chinner
2023-07-22 3:12 ` Jens Axboe
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