public inbox for [email protected]
 help / color / mirror / Atom feed
From: Jens Axboe <[email protected]>
To: Pavel Begunkov <[email protected]>, [email protected]
Cc: [email protected], Kanchan Joshi <[email protected]>,
	Ming Lei <[email protected]>
Subject: Re: [PATCH 11/11] io_uring: get rid of intermediate aux cqe caches
Date: Fri, 15 Mar 2024 10:27:49 -0600	[thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>

On 3/15/24 10:25 AM, Jens Axboe wrote:
> On 3/15/24 10:23 AM, Pavel Begunkov wrote:
>> On 3/15/24 16:20, Jens Axboe wrote:
>>> On 3/15/24 9:30 AM, Pavel Begunkov wrote:
>>>> io_post_aux_cqe(), which is used for multishot requests, delays
>>>> completions by putting CQEs into a temporary array for the purpose
>>>> completion lock/flush batching.
>>>>
>>>> DEFER_TASKRUN doesn't need any locking, so for it we can put completions
>>>> directly into the CQ and defer post completion handling with a flag.
>>>> That leaves !DEFER_TASKRUN, which is not that interesting / hot for
>>>> multishot requests, so have conditional locking with deferred flush
>>>> for them.
>>>
>>> This breaks the read-mshot test case, looking into what is going on
>>> there.
>>
>> I forgot to mention, yes it does, the test makes odd assumptions about
>> overflows, IIRC it expects that the kernel allows one and only one aux
>> CQE to be overflown. Let me double check
> 
> Yeah this is very possible, the overflow checking could be broken in
> there. I'll poke at it and report back.

It does, this should fix it:


diff --git a/test/read-mshot.c b/test/read-mshot.c
index 8fcb79857bf0..501ca69a98dc 100644
--- a/test/read-mshot.c
+++ b/test/read-mshot.c
@@ -236,7 +236,7 @@ static int test(int first_good, int async, int overflow)
 		}
 		if (!(cqe->flags & IORING_CQE_F_MORE)) {
 			/* we expect this on overflow */
-			if (overflow && (i - 1 == NR_OVERFLOW))
+			if (overflow && i >= NR_OVERFLOW)
 				break;
 			fprintf(stderr, "no more cqes\n");
 			return 1;

-- 
Jens Axboe


  reply	other threads:[~2024-03-15 16:27 UTC|newest]

Thread overview: 54+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-03-15 15:29 [PATCH 00/11] remove aux CQE caches Pavel Begunkov
2024-03-15 15:29 ` [PATCH 01/11] io_uring: fix poll_remove stalled req completion Pavel Begunkov
2024-03-15 15:29 ` [PATCH 02/11] io_uring/cmd: kill one issue_flags to tw conversion Pavel Begunkov
2024-03-15 15:29 ` [PATCH 03/11] io_uring/cmd: fix tw <-> issue_flags conversion Pavel Begunkov
2024-03-15 15:29 ` [PATCH 04/11] io_uring/cmd: introduce io_uring_cmd_complete Pavel Begunkov
2024-03-15 15:29 ` [PATCH 05/11] ublk: don't hard code IO_URING_F_UNLOCKED Pavel Begunkov
2024-03-15 15:29 ` [PATCH 06/11] nvme/io_uring: " Pavel Begunkov
2024-03-15 15:29 ` [PATCH 07/11] io_uring/rw: avoid punting to io-wq directly Pavel Begunkov
2024-03-15 15:29 ` [PATCH 08/11] io_uring: force tw ctx locking Pavel Begunkov
2024-03-15 15:40   ` Jens Axboe
2024-03-15 16:14     ` Pavel Begunkov
2024-03-15 15:29 ` [PATCH 09/11] io_uring: remove struct io_tw_state::locked Pavel Begunkov
2024-03-15 15:30 ` [PATCH 10/11] io_uring: refactor io_fill_cqe_req_aux Pavel Begunkov
2024-03-15 15:30 ` [PATCH 11/11] io_uring: get rid of intermediate aux cqe caches Pavel Begunkov
2024-03-15 16:20   ` Jens Axboe
2024-03-15 16:23     ` Pavel Begunkov
2024-03-15 16:25       ` Jens Axboe
2024-03-15 16:27         ` Jens Axboe [this message]
2024-03-15 16:44           ` Pavel Begunkov
2024-03-15 16:49             ` Jens Axboe
2024-03-15 17:26               ` Pavel Begunkov
2024-03-15 18:26                 ` Jens Axboe
2024-03-15 18:51                   ` Pavel Begunkov
2024-03-15 19:02                     ` Jens Axboe
2024-03-15 16:29         ` Pavel Begunkov
2024-03-15 16:33           ` Jens Axboe
2024-03-15 15:42 ` [PATCH 00/11] remove aux CQE caches Jens Axboe
2024-03-15 16:00 ` Jens Axboe
2024-03-15 22:53 ` (subset) " Jens Axboe
2024-03-16  2:03   ` Ming Lei
2024-03-16  2:24     ` Ming Lei
2024-03-16  2:54       ` Pavel Begunkov
2024-03-16  3:54         ` Ming Lei
2024-03-16  4:13           ` Pavel Begunkov
2024-03-16  4:20             ` Pavel Begunkov
2024-03-16  9:53               ` Ming Lei
2024-03-16 11:52   ` Ming Lei
2024-03-16 13:27     ` Pavel Begunkov
2024-03-16 13:56       ` Ming Lei
2024-03-17 20:55         ` Pavel Begunkov
2024-03-17 21:24           ` Jens Axboe
2024-03-17 21:29             ` Pavel Begunkov
2024-03-17 21:32               ` Jens Axboe
2024-03-17 21:34                 ` Pavel Begunkov
2024-03-17 21:47                   ` Pavel Begunkov
2024-03-17 21:51                     ` Jens Axboe
2024-03-17 22:07                       ` Jens Axboe
2024-03-17 22:24                         ` Jens Axboe
2024-03-18  0:15                           ` Ming Lei
2024-03-18  1:34                             ` Jens Axboe
2024-03-18  1:44                               ` Jens Axboe
2024-03-18  1:49                               ` Ming Lei
2024-03-17 23:16                       ` Pavel Begunkov
2024-03-16 14:39       ` Jens Axboe

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox