netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Cong Wang <xiyou.wangcong@gmail.com>
To: "Holger Hoffstätte" <holger@applied-asynchrony.com>
Cc: Netdev <netdev@vger.kernel.org>
Subject: Re: Default qdisc not correctly initialized with custom MTU
Date: Mon, 9 Sep 2019 15:52:21 -0700	[thread overview]
Message-ID: <CAM_iQpWKsSWDZ55kMO6mzDe5C7tHW-ub_eH91hRzZMdUtKJtfA@mail.gmail.com> (raw)
In-Reply-To: <211c7151-7500-f895-7fd7-2c868dd48579@applied-asynchrony.com>

On Mon, Sep 9, 2019 at 5:44 AM Holger Hoffstätte
<holger@applied-asynchrony.com> wrote:
> I can't help but feel this is a slight bug in terms of initialization order,
> and that the default qdisc should only be created when it's first being
> used/attached to a link, not when the sysctls are configured.

Yeah, this is because the fq_codel qdisc is initialized once and
doesn't get any notification when the netdev's MTU get changed.
We can "fix" this by adding a NETDEV_CHANGEMTU notifier to
qdisc's, but I don't know if it is really worth the effort.

Is there any reason you can't change that order?

Thanks.

  reply	other threads:[~2019-09-09 22:52 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-08 14:13 Default qdisc not correctly initialized with custom MTU Holger Hoffstätte
2019-09-09 22:52 ` Cong Wang [this message]
2019-09-10  9:14   ` Holger Hoffstätte
2019-09-10 16:56     ` Cong Wang
2019-09-10 17:45       ` Holger Hoffstätte

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 \
    --in-reply-to=CAM_iQpWKsSWDZ55kMO6mzDe5C7tHW-ub_eH91hRzZMdUtKJtfA@mail.gmail.com \
    --to=xiyou.wangcong@gmail.com \
    --cc=holger@applied-asynchrony.com \
    --cc=netdev@vger.kernel.org \
    /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;
as well as URLs for NNTP newsgroup(s).