From: Stephen Hemminger <stephen@networkplumber.org>
To: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alasdair McWilliam <alasdair@mcwilliam.dev>,
netdev@vger.kernel.org, Andrew Lunn <andrew+netdev@lunn.ch>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>
Subject: Re: [PATCH] rtnetlink: add needed_{head,tail}room attributes
Date: Mon, 15 Sep 2025 10:20:05 -0700 [thread overview]
Message-ID: <20250915102005.2ddf29d7@hermes.local> (raw)
In-Reply-To: <e742f9e0-671d-4058-99af-c3e38b73ec0d@iogearbox.net>
On Mon, 15 Sep 2025 18:49:55 +0200
Daniel Borkmann <daniel@iogearbox.net> wrote:
> Hi Alasdair,
>
> On 9/15/25 6:32 PM, Alasdair McWilliam wrote:
> > Various network interface types make use of needed_{head,tail}room values
> > to efficiently reserve buffer space for additional encapsulation headers,
> > such as VXLAN, Geneve, IPSec, etc. However, it is not currently possible
> > to query these values in a generic way.
> >
> > Introduce ability to query the needed_{head,tail}room values of a network
> > device via rtnetlink, such that applications that may wish to use these
> > values can do so.
> >
> > Signed-off-by: Alasdair McWilliam <alasdair@mcwilliam.dev>
Why is this info needed in user space?
How would an application use this?
Seems like a hardware specific optimization that should be hidden in driver.
next prev parent reply other threads:[~2025-09-15 17:20 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-09-15 16:32 [PATCH] rtnetlink: add needed_{head,tail}room attributes Alasdair McWilliam
2025-09-15 16:49 ` Daniel Borkmann
2025-09-15 17:20 ` Stephen Hemminger [this message]
2025-09-15 18:30 ` Daniel Borkmann
2025-09-16 10:56 ` Alasdair McWilliam
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