From: Jakub Kicinski <kuba@kernel.org>
To: Christoph Paasch <cpaasch@apple.com>
Cc: netdev <netdev@vger.kernel.org>, Roopa Prabhu <roopa@nvidia.com>,
Craig Taylor <cmtaylor@apple.com>
Subject: Re: mpls_xmit() calls skb_orphan()
Date: Fri, 8 Dec 2023 15:44:46 -0800 [thread overview]
Message-ID: <20231208154446.0feee63f@kernel.org> (raw)
In-Reply-To: <7915A22A-F1ED-4A5D-AC2A-25D0C05ECAA0@apple.com>
Updating Roopa's email.
On Fri, 08 Dec 2023 13:15:04 -0800 Christoph Paasch wrote:
> > On Dec 8, 2023, at 1:06 PM, Christoph Paasch <cpaasch@apple.com> wrote:
> >
> > Hello,
> >
> > we observed an issue when running a TCP-connection with BBR on top of an MPLS-tunnel in that we saw a lot of CPU-time spent coming from tcp_pace_kick(), although sch_fq was configured on this host.
> >
> > The reason for this seems to be because mpls_xmit() calls skb_orphan(), thus settings skb->sk to NULL, preventing the qdisc to set sk_pacing_status (which would allow to avoid the call to tcp_pace_kick()).
> >
> > The question is: Why is this call to skb_orphan in mpls_xmit necessary ?
> >
> >
> > Thanks,
> > Christoph
>
> Resend in plain-text. Sorry about that!
next prev parent reply other threads:[~2023-12-08 23:44 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-08 21:06 mpls_xmit() calls skb_orphan() Christoph Paasch
2023-12-08 21:15 ` Christoph Paasch
2023-12-08 23:44 ` Jakub Kicinski [this message]
2024-02-22 16:34 ` Paolo Abeni
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