From: Jakub Kicinski <kuba@kernel.org>
To: Simon Horman <horms@kernel.org>, thomas.perrot@bootlin.com
Cc: Nicolas Ferre <nicolas.ferre@microchip.com>,
Claudiu Beznea <claudiu.beznea@tuxon.dev>,
"David S . Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Paolo Abeni <pabeni@redhat.com>,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH net-next] net: macb: allow MTU change when the interface is up
Date: Mon, 25 Mar 2024 18:56:47 -0700 [thread overview]
Message-ID: <20240325185647.0ad674e9@kernel.org> (raw)
In-Reply-To: <20240325205401.GF403975@kernel.org>
On Mon, 25 Mar 2024 20:54:01 +0000 Simon Horman wrote:
> I'm not sure that it is expected behaviour for an interface
> to reset like this when a change of MTU is requested.
> While conversely I think it is common (if not entirely desirable)
> to prohibit changing the MTU when an interface is up.
> What is the problem being addressed here?
Right..
> > dev->mtu = new_mtu;
> >
> > + if (reset)
> > + macb_open(dev);
.. imagine admin does this over SSH on a remote box and system
is under memory pressure. Even ignoring the fact you're not checking
the return value, the result of changing MTU should be either having
the requested MTU (success) or having the old MTU (failure).
Not "machine drops off the network" :(
next prev parent reply other threads:[~2024-03-26 1:56 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-25 15:27 [PATCH net-next] net: macb: allow MTU change when the interface is up thomas.perrot
2024-03-25 20:54 ` Simon Horman
2024-03-26 1:56 ` Jakub Kicinski [this message]
2024-03-26 8:49 ` Thomas Perrot
2024-03-26 9:30 ` Simon Horman
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