lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Tue, 30 Dec 2014 12:15:01 -0800
From:	Cong Wang <>
To:	Dennis Chen <>
Cc:	netdev <>
Subject: Re: [Question] What's the noop_qdisc introduced for in the kernel?

On Tue, Dec 30, 2014 at 1:23 AM, Dennis Chen <> wrote:
> After google and the code reading, seems this Qdisc instance is only
> used for the initialization purpose, I can't find the reason that this
> object introduced in the kernel. Does anybody know what the historical
> reason is for this invention? the purpose or the benefit for this
> Qdisc object?

Not just for initialization, it is kinda a null qdisc when
the previous qdisc gets removed:

        /* ... and graft new one */
        if (qdisc == NULL)
                qdisc = &noop_qdisc;

or the entire device is not activated yet. It guarantees no
packets can be sent out via this qdisc.
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to
More majordomo info at

Powered by blists - more mailing lists