From: Pavel Begunkov <[email protected]>
To: Jens Axboe <[email protected]>, [email protected]
Subject: Re: [RFC 0/9] scrap 24 bytes from io_kiocb
Date: Sun, 12 Jul 2020 20:34:53 +0300 [thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
On 12/07/2020 18:59, Jens Axboe wrote:
> On 7/12/20 3:41 AM, Pavel Begunkov wrote:
>> Make io_kiocb slimmer by 24 bytes mainly by revising lists usage. The
>> drawback is adding extra kmalloc in draining path, but that's a slow
>> path, so meh. It also frees some space for the deferred completion path
>> if would be needed in the future, but the main idea here is to shrink it
>> to 3 cachelines in the end.
>>
>> I'm not happy yet with a few details, so that's not final, but it would
>> be lovely to hear some feedback.
>
> I think it looks pretty good, most of the changes are straight forward.
> Adding a completion entry that shares the submit space is a good idea,
> and really helps bring it together.
>
> From a quick look, the only part I'm not super crazy about is patch #3.
Thanks!
> I'd probably rather use a generic list name and not unionize the tw
> lists.
I don't care much, but without compiler's help always have troubles
finding and distinguishing something as generic as "list".
BTW, I thought out how to bring it down to 3 cache lines, but that would
require taking io_wq_work out of io_kiocb and kmalloc'ing it on demand.
And there should also be a bunch of nice side effects like improving apoll.
--
Pavel Begunkov
next prev parent reply other threads:[~2020-07-12 17:36 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-12 9:41 [RFC 0/9] scrap 24 bytes from io_kiocb Pavel Begunkov
2020-07-12 9:41 ` [PATCH 1/9] io_uring: share completion list w/ per-op space Pavel Begunkov
2020-07-12 9:41 ` [PATCH 2/9] io_uring: rename ctx->poll into ctx->iopoll Pavel Begunkov
2020-07-12 9:41 ` [PATCH 3/9] io_uring: use inflight_entry list for iopolling Pavel Begunkov
2020-07-12 9:41 ` [PATCH 4/9] io_uring: use competion list for CQ overflow Pavel Begunkov
2020-07-12 9:41 ` [PATCH 5/9] io_uring: add req->timeout.list Pavel Begunkov
2020-07-12 9:41 ` [PATCH 6/9] io_uring: remove init for unused list Pavel Begunkov
2020-07-12 9:41 ` [PATCH 7/9] io_uring: kill rq->list and allocate it on demand Pavel Begunkov
2020-07-12 9:41 ` [PATCH 8/9] io_uring: remove sequence from io_kiocb Pavel Begunkov
2020-07-12 9:41 ` [PATCH 9/9] io_uring: place cflags into completion data Pavel Begunkov
2020-07-12 15:59 ` [RFC 0/9] scrap 24 bytes from io_kiocb Jens Axboe
2020-07-12 17:34 ` Pavel Begunkov [this message]
2020-07-12 20:32 ` Jens Axboe
2020-07-13 8:17 ` Pavel Begunkov
2020-07-13 8:17 ` Pavel Begunkov
2020-07-13 14:12 ` Jens Axboe
2020-07-13 20:45 ` Pavel Begunkov
2020-07-13 21:00 ` Jens Axboe
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