From mboxrd@z Thu Jan  1 00:00:00 1970
From: Johannes Berg <johannes@sipsolutions.net>
Subject: Re: [iproute PATCH] libnetlink: Double the dump buffer size
Date: Sat, 05 Mar 2016 22:12:16 +0100
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To: Stephen Hemminger <shemming@brocade.com>, Phil Sutter <phil@nwl.cc>
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On Fri, 2016-03-04 at 15:35 -0800, Stephen Hemminger wrote:
>=C2=A0
> > There have been reports about 'ip addr' printing "Message
> > truncated" on
[...]
> I thought this was addressed in kernel by making the VF info
> optional.
> The netlink protocol is showing some strain, this is one of them.

I don't know how the dump is split here, but we had a similar issue
with nl80211 - originally each physical device info had to fit into a
single message (one message during dump for each device), but we fixed
that by having userspace to set a flag when it's able to understand a
multi-message single physical device info.

Before:
=C2=A0msg1: phy1: A, B, C
=C2=A0msg2: phy2: A, B, C

After:
=C2=A0msg1: phy1: A
=C2=A0msg2: phy1: B
=C2=A0msg3: phy1: C
=C2=A0msg4: phy1: D
=C2=A0msg5: phy2: A
=C2=A0[...]

=46or userspace not setting the flag, it only get partial info today fo=
r
compatibility (A, B, C, not D), but in our particular case this was
perfectly reasonable since it would be unaware of the new capabilities
anyway.

I don't know precisely enough what the issue at hand is to comment
whether such an approach will be feasible here, but it seems it could
be.

johannes