From mboxrd@z Thu Jan  1 00:00:00 1970
From: Eric Dumazet <eric.dumazet@gmail.com>
Subject: Re: pkt_sched: gen_estimator: more fuel for Jarek and Changli
Date: Wed, 09 Jun 2010 09:36:04 +0200
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Cc: Changli Gao <xiaosuo@gmail.com>,
	David Miller <davem@davemloft.net>,
	netdev <netdev@vger.kernel.org>,
	Stephen Hemminger <shemminger@vyatta.com>,
	Patrick McHardy <kaber@trash.net>
To: Jarek Poplawski <jarkao2@gmail.com>
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Le mercredi 09 juin 2010 =C3=A0 06:51 +0000, Jarek Poplawski a =C3=A9cr=
it :
> On Wed, Jun 09, 2010 at 08:13:17AM +0200, Eric Dumazet wrote:
> >=20
> > With un-modified kernel, I ran following scripts on my machine
>=20
> Why not modified with your other patch quite obviously needed by
> rateest?:
>=20

=46irst patch is obvious, but I cooked same script to trigger both bugs=
,
because you needed some evidences.

> > [PATCH net-2.6] pkt_sched: gen_estimator: add a new lock
> >=20
> > gen_kill_estimator() / gen_new_estimator() is not always called wit=
h
> > RTNL held.
>=20
> Btw, I agree with Changli that adding RTNL to rateest (if possible),
> and doing the RTNL replacement later, seems more proper.
>=20

I wont be the guy adding RTNL to netfilter, thats for sure. That would
be a step backward.=20
Sometimes, the 'obvious' fix is also a dumb one.
Do you really think I didnt had this idea too ?

xt_RATEEST is an unfortunate domain intersection (netfilter / sched).

We can solve this using a fine grained lock, instead of interesting
lockdep issues, yet to be discovered.

You can submit your patch, but I wont Ack it, I'll Nack it for all thes=
e
reasons.

Why dont we remove all locks we have 'because we can use RTNL and be
with it' ?

qdisc_mod_lock could be removed quite instantly, qdisc_base could be
protected by RTNL... And so on...