linux-kernel - Re: Fw: [Bug 220774] New: netem is broken in 6.18

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Message-ID: <aSDdYoK7Vhw9ONzN@pop-os.localdomain>
Date: Fri, 21 Nov 2025 13:45:06 -0800
From: Cong Wang <xiyou.wangcong@...il.com>
To: Jamal Hadi Salim <jhs@...atatu.com>
Cc: Stephen Hemminger <stephen@...workplumber.org>, netdev@...r.kernel.org,
	kuba@...nel.org, linux-kernel@...r.kernel.org, will@...lsroot.io,
	jschung2@...ton.me, savy@...t3mfailure.io
Subject: Re: Fw: [Bug 220774] New: netem is broken in 6.18

On Fri, Nov 21, 2025 at 07:52:37AM -0500, Jamal Hadi Salim wrote:

> jschung2@...ton.me: Can you please provide more details about what you
> are trying to do so we can see if a different approach can be
> prescribed?
> 

An alternative approach is to use eBPF qdisc to replace netem, but:
1) I am not sure if we could duplicate and re-inject a packet in eBPF Qdisc
2) I doubt everyone wants to write eBPF code when they already have a
working cmdline.

BTW, Jamal, if your plan is to solve them one by one, even if it could work,
it wouldn't scale. There are still many users don't get hit by this
regression yet (not until hitting LTS or major distro).

Regards,
Cong