From: Li RongQing <roy.qing.li@gmail.com>
To: Stephen Hemminger <stephen@networkplumber.org>
Cc: netdev <netdev@vger.kernel.org>
Subject: Re: [PATCH][net-next][v2] bridge: allow the maximum mtu to 64k
Date: Thu, 25 Feb 2016 09:50:41 +0800 [thread overview]
Message-ID: <CAJFZqHwiJiMnEvq9mWZJqPbsm_VkDLPxMkgLt-UtwUTynA1RKQ@mail.gmail.com> (raw)
In-Reply-To: <20160224134456.3ea94f0a@xeon-e3>
On Thu, Feb 25, 2016 at 5:44 AM, Stephen Hemminger
<stephen@networkplumber.org> wrote:
>> This is especially annoying for the virtualization case because the
>> KVM's tap driver will by default adopt the bridge's MTU on startup
>> making it impossible (without the workaround) to use a large MTU on the
>> guest VMs.
>>
>> https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1399064
>
> This use case looks like KVM misusing bridge MTU. I.e it should set TAP
> MTU to what it wants then enslave it, not vice versa.
1. a use should be able to configure an empty bridge MTU to a higher
mtu than 1500
2. if first configure the tap MTU a higher value, other port is lower
value, the pmtu
will be used, it maybe lower performance.
the configuration process is written into libvirt, located in
virnetdevtap.c, of cause it can
be improved to fix this issue.
https://www.redhat.com/archives/libvir-list/2008-December/msg00083.html
-R
next prev parent reply other threads:[~2016-02-25 1:50 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-23 1:00 [PATCH][net-next][v2] bridge: allow the maximum mtu to 64k roy.qing.li
2016-02-24 20:57 ` David Miller
2016-02-24 21:44 ` Stephen Hemminger
2016-02-25 1:50 ` Li RongQing [this message]
2016-02-25 19:28 ` David Miller
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=CAJFZqHwiJiMnEvq9mWZJqPbsm_VkDLPxMkgLt-UtwUTynA1RKQ@mail.gmail.com \
--to=roy.qing.li@gmail.com \
--cc=netdev@vger.kernel.org \
--cc=stephen@networkplumber.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).