Re: Deleting child qdisc doesn't reset parent to default qdisc?

From	Jamal Hadi Salim <jhs@mojatatu.com>
Newsgroups	linux.kernel
Subject	Re: Deleting child qdisc doesn't reset parent to default qdisc?
Date	2016-04-15 14:50 +0200
Message-ID	<robma-36m-15@gated-at.bofh.it> (permalink)
References	<rnQKL-3gf-29@gated-at.bofh.it> <rnR48-3Fm-83@gated-at.bofh.it> <rnRdM-3Ro-31@gated-at.bofh.it> <rnS0b-4DT-27@gated-at.bofh.it> <rnTyX-5JF-39@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

On 16-04-14 01:49 PM, Eric Dumazet wrote:

> And what would be the chosen behavior ?
>

TBF is probably a bad example because it started life as
a classless qdisc. There was only one built-in fifo queue
that was shaped. Then someone made it classful and changed
this behavior. To me it sounds reasonable to have the
default behavior restored. At minimal consistency.

> Relying on TBF installing a bfifo for you at delete would be hazardous.
>
> For example CBQ got it differently than HFSC
>
> If qdisc_create_dflt() fails in CBQ, we fail the 'delete', while HFSC
> falls back to noop_qdisc, without warning the user :(
>
> At least always using noop_qdisc is consistent. No magic there.
>
> Doing 'unification' right now would break existing scripts.
>
> This is too late, I am afraid.

Sigh. So rant:
IMO, we should let any new APIs and API updates stay longer
in discussion. Or better mark them as unstable for sometime.
The excuse that "it is out in the wild therefore cant be changed"
is harmful because the timeline is "forever" whereas
patches are applied after a short period of posting
and discussions and sometimes not involving the right people.
It is like having a jury issuing a death sentence after 1 week of
deliberation. You cant take it back after execution.

cheers,
jamal

Thread

Deleting child qdisc doesn't reset parent to default qdisc? Jiri Kosina <jikos@kernel.org> - 2016-04-14 16:50 +0200
  Re: Deleting child qdisc doesn't reset parent to default qdisc? Jiri Kosina <jikos@kernel.org> - 2016-04-14 17:00 +0200
  Re: Deleting child qdisc doesn't reset parent to default qdisc? Eric Dumazet <eric.dumazet@gmail.com> - 2016-04-14 17:10 +0200
    Re: Deleting child qdisc doesn't reset parent to default qdisc? Phil Sutter <phil@nwl.cc> - 2016-04-14 17:20 +0200
      Re: Deleting child qdisc doesn't reset parent to default qdisc? Jiri Kosina <jikos@kernel.org> - 2016-04-14 17:40 +0200
        Re: Deleting child qdisc doesn't reset parent to default qdisc? Eric Dumazet <eric.dumazet@gmail.com> - 2016-04-14 17:50 +0200
          Re: Deleting child qdisc doesn't reset parent to default qdisc? Phil Sutter <phil@nwl.cc> - 2016-04-14 18:30 +0200
            Re: Deleting child qdisc doesn't reset parent to default qdisc? Eric Dumazet <eric.dumazet@gmail.com> - 2016-04-14 18:50 +0200
      Re: Deleting child qdisc doesn't reset parent to default qdisc? Jiri Kosina <jikos@kernel.org> - 2016-04-14 18:10 +0200
        Re: Deleting child qdisc doesn't reset parent to default qdisc? Eric Dumazet <eric.dumazet@gmail.com> - 2016-04-14 19:50 +0200
          Re: Deleting child qdisc doesn't reset parent to default qdisc? Jamal Hadi Salim <jhs@mojatatu.com> - 2016-04-15 14:50 +0200
            Re: Deleting child qdisc doesn't reset parent to default qdisc? Eric Dumazet <eric.dumazet@gmail.com> - 2016-04-15 17:00 +0200
              Re: Deleting child qdisc doesn't reset parent to default qdisc? David Miller <davem@davemloft.net> - 2016-04-15 19:20 +0200

csiph-web