From: Bijan Mottahedeh <[email protected]>
To: Pavel Begunkov <[email protected]>, [email protected]
Cc: [email protected]
Subject: Re: [PATCH 0/8] io_uring: buffer registration enhancements
Date: Mon, 16 Nov 2020 16:21:49 -0800 [thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
>> This patchset is the follow-on to my previous RFC which implements a
>> set of enhancements to buffer registration consistent with existing file
>> registration functionality:
>
> I like the idea of generic resource handling
>
>>
>> - buffer registration updates IORING_REGISTER_BUFFERS_UPDATE
>> IORING_OP_BUFFERS_UPDATE
>
> Do you need it for something specific?
Incremental buffer registration, see below.
>
>>
>> - readv/writev with fixed buffers IOSQE_FIXED_BUFFER
>
> Why do we need it?
It makes fixed files/buffers APIs more consistent, and once the initial
work of generic resource handling is done, the additional work for this
support is not much I think.
>
>>
>> - buffer registration sharing IORING_SETUP_SHARE_BUF
>> IORING_SETUP_ATTACH_BUF
>
> I haven't looked it up. What's the overhead on that?
> And again, do you really need it?
For our use case, a DB instance may have a shared memory size of TB
order and very large number of processes (1000+) using that memory. The
cost of each process registering that memory could become prohibitive.
We need to allow for incremental buffer registration given the
potentially large size of the shared memory. It also makes the API
between files/buffers more consistent.
I had a chat with Jens a while back and he also felt that the static
nature of buffer registrations and the requirement to reload the full
set in case of changes was problematic.
>
> The set is +600 lines, so just want to know that there is
> a real benefit from having it.
Sure, understood.
prev parent reply other threads:[~2020-11-17 0:24 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-12 23:00 [PATCH 0/8] io_uring: buffer registration enhancements Bijan Mottahedeh
2020-11-12 23:00 ` [PATCH 1/8] io_uring: modularize io_sqe_buffer_register Bijan Mottahedeh
2020-11-12 23:00 ` [PATCH 2/8] io_uring: modularize io_sqe_buffers_register Bijan Mottahedeh
2020-11-12 23:00 ` [PATCH 3/8] io_uring: generalize fixed file functionality Bijan Mottahedeh
2020-11-12 23:00 ` [PATCH 4/8] io_uring: implement fixed buffers registration similar to fixed files Bijan Mottahedeh
2020-11-15 13:33 ` Pavel Begunkov
2020-11-16 21:24 ` Bijan Mottahedeh
2020-11-16 23:09 ` Pavel Begunkov
2020-11-17 0:41 ` Bijan Mottahedeh
2020-11-12 23:00 ` [PATCH 5/8] io_uring: generalize files_update functionlity to rsrc_update Bijan Mottahedeh
2020-11-12 23:00 ` [PATCH 6/8] io_uring: support buffer registration updates Bijan Mottahedeh
2020-11-18 20:17 ` Pavel Begunkov
2020-12-09 0:42 ` Bijan Mottahedeh
2020-11-12 23:00 ` [PATCH 7/8] io_uring: support readv/writev with fixed buffers Bijan Mottahedeh
2020-11-17 11:04 ` Pavel Begunkov
2020-11-17 22:59 ` Bijan Mottahedeh
2020-11-18 9:14 ` Pavel Begunkov
2020-11-18 20:12 ` Pavel Begunkov
[not found] ` <[email protected]>
[not found] ` <[email protected]>
2020-11-19 19:27 ` Bijan Mottahedeh
2020-11-12 23:00 ` [PATCH 8/8] io_uring: support buffer registration sharing Bijan Mottahedeh
2020-11-16 23:28 ` [PATCH 0/8] io_uring: buffer registration enhancements Pavel Begunkov
2020-11-17 0:21 ` Bijan Mottahedeh [this message]
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