From: Jens Axboe <[email protected]>
To: Hao Xu <[email protected]>, [email protected]
Cc: [email protected], Dylan Yudaken <[email protected]>
Subject: Re: [PATCH 3/3] io_uring: add support for ring mapped supplied buffers
Date: Wed, 18 May 2022 06:48:37 -0600 [thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
On 5/18/22 4:50 AM, Hao Xu wrote:
>> This is known at compile time, so the compiler should already be doing
>> that as it's a constant.
>>
>>>> + buf = page_address(bl->buf_pages[index]);
>>>> + buf += off;
>>>> + }
>>>
>>> I'm not familiar with this part, allow me to ask, is this if else
>>> statement for efficiency? why choose one page as the dividing line
>>
>> We need to index at the right page granularity.
>
> Sorry, I didn't get it, why can't we just do buf = &br->bufs[tail];
> It seems something is beyond my knowledge..
The pages might not be contigious, we have to index from the right page.
--
Jens Axboe
next prev parent reply other threads:[~2022-05-18 12:49 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-16 16:21 [PATCHSET v6 0/3] Add support for ring mapped provided buffers Jens Axboe
2022-05-16 16:21 ` [PATCH 1/3] io_uring: add buffer selection support to IORING_OP_NOP Jens Axboe
2022-05-16 16:21 ` [PATCH 2/3] io_uring: add io_pin_pages() helper Jens Axboe
2022-05-16 16:21 ` [PATCH 3/3] io_uring: add support for ring mapped supplied buffers Jens Axboe
2022-05-17 14:18 ` Hao Xu
2022-05-17 15:46 ` Jens Axboe
2022-05-18 10:50 ` Hao Xu
2022-05-18 12:48 ` Jens Axboe [this message]
2022-05-17 14:20 ` [PATCHSET v6 0/3] Add support for ring mapped provided buffers Hao Xu
2022-05-17 15:44 ` Jens Axboe
-- strict thread matches above, loose matches on Subject: below --
2022-05-07 14:30 [PATCHSET v5 " Jens Axboe
2022-05-07 14:30 ` [PATCH 3/3] io_uring: add support for ring mapped supplied buffers Jens Axboe
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