From: Jakub Kicinski <kuba@kernel.org>
To: Qingfang Deng <dqfext@gmail.com>
Cc: linux-ppp@vger.kernel.org, James Chapman <jchapman@katalix.com>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Paolo Abeni <pabeni@redhat.com>, Simon Horman <horms@kernel.org>,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH net] l2tp: ppp: use max L2TP header size for PPP channel hdrlen
Date: Mon, 16 Mar 2026 19:54:59 -0700 [thread overview]
Message-ID: <20260316195459.6e4d6d9b@kernel.org> (raw)
In-Reply-To: <20260313034732.209792-1-dqfext@gmail.com>
On Fri, 13 Mar 2026 11:47:31 +0800 Qingfang Deng wrote:
> chan.hdrlen is read once at channel registration by
> ppp_register_net_channel(), and used to set the PPP net device's
> hard_header_len. It was set to PPPOL2TP_L2TP_HDR_SIZE_NOSEQ (6), which
> is 4 bytes too small if sequence numbers are later enabled via
> setsockopt(PPPOL2TP_SO_SENDSEQ), causing unnecessary skb reallocations
> on the TX path.
If the main effect of this patch is that we avoid reallocations I think
this is an optimization and should go to net-next? If there's more to
it please explain in the commit msg a bit more.
--
pw-bot: cr
next prev parent reply other threads:[~2026-03-17 2:55 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-13 3:47 [PATCH net] l2tp: ppp: use max L2TP header size for PPP channel hdrlen Qingfang Deng
2026-03-17 2:54 ` Jakub Kicinski [this message]
2026-03-17 3:06 ` Qingfang Deng
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