archive mirror
 help / color / mirror / Atom feed
From: Jens Axboe <>
To: yangerkun <>,
Subject: Re: [PATCH V3] io_uring: consider the overflow of sequence for timeout req
Date: Tue, 15 Oct 2019 08:52:11 -0600	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <>

On 10/15/19 7:59 AM, yangerkun wrote:
> Now we recalculate the sequence of timeout with 'req->sequence =
> ctx->cached_sq_head + count - 1', judge the right place to insert
> for timeout_list by compare the number of request we still expected for
> completion. But we have not consider about the situation of overflow:
> 1. ctx->cached_sq_head + count - 1 may overflow. And a bigger count for
> the new timeout req can have a small req->sequence.
> 2. cached_sq_head of now may overflow compare with before req. And it
> will lead the timeout req with small req->sequence.
> This overflow will lead to the misorder of timeout_list, which can lead
> to the wrong order of the completion of timeout_list. Fix it by reuse
> req->submit.sequence to store the count, and change the logic of
> inserting sort in io_timeout.

Thanks, this looks great. Applied for 5.4.

Jens Axboe

  reply	other threads:[~2019-10-15 14:52 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-15 13:59 [PATCH V3] io_uring: consider the overflow of sequence for timeout req yangerkun
2019-10-15 14:52 ` Jens Axboe [this message]
2019-10-16  1:35 ` yangerkun
2019-10-16  1:45   ` Jens Axboe
2019-10-16  2:19     ` yangerkun

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:

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

  git send-email \ \ \ \ \ \ \

* 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;
as well as URLs for NNTP newsgroup(s).