From: Jarek Poplawski <jarkao2@gmail.com>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: hadi@cyberus.ca, David Miller <davem@davemloft.net>,
netdev <netdev@vger.kernel.org>
Subject: Re: [PATCH net-next V3] net: dynamic ingress_queue allocation
Date: Mon, 4 Oct 2010 16:24:15 +0200 [thread overview]
Message-ID: <20101004142415.GA2049@del.dom.local> (raw)
In-Reply-To: <1286196720.18293.196.camel@edumazet-laptop>
On Mon, Oct 04, 2010 at 02:52:00PM +0200, Eric Dumazet wrote:
> Le lundi 04 octobre 2010 ?? 14:06 +0200, Jarek Poplawski a écrit :
>
> > Right, but then at least in qdisc_lookup():
> >
> > if (dev_ingress_queue(dev))
> > q = qdisc_match_from_root(dev_ingress_queue(dev), handle);
> >
> > you should use a variable instead of the second dereference (rtnl isn't
> > mandatory here).
>
> I am lost.
>
> If rntl is not mandatory, what is the lock that protects us ?
>
> qdisc_lookup() _is_ called under the protection of a lock.
> Or as soon as we return from it, result could change under us.
>
> Please name it, and I'll use it :
>
> rcu_dereference_protected(dev->ingress_queue, lockdep_is_held(THISLOCK))
>
You are right! There is no other lock. (I forgot I removed
qdisc_list_lock already ;-)
Sorry,
Jarek P.
next prev parent reply other threads:[~2010-10-04 14:24 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-09-28 15:58 [PATCH net-next2.6] net: rename netdev rx_queue to ingress_queue Eric Dumazet
2010-09-28 18:04 ` Jarek Poplawski
2010-09-29 10:56 ` jamal
2010-09-29 13:18 ` Jarek Poplawski
2010-09-29 16:54 ` Jarek Poplawski
2010-09-30 22:58 ` [PATCH net-next2.6] net: dynamic ingress_queue allocation Eric Dumazet
2010-10-01 11:45 ` jamal
2010-10-01 13:56 ` [PATCH net-next V2] " Eric Dumazet
2010-10-02 9:32 ` Jarek Poplawski
2010-10-02 16:11 ` [PATCH net-next V3] " Eric Dumazet
2010-10-03 9:42 ` Jarek Poplawski
2010-10-03 13:10 ` jamal
2010-10-04 8:42 ` Eric Dumazet
2010-10-04 9:00 ` [PATCH net-next] net: relax rtnl_dereference() Eric Dumazet
2010-10-05 7:29 ` David Miller
2010-10-04 12:06 ` [PATCH net-next V3] net: dynamic ingress_queue allocation Jarek Poplawski
2010-10-04 12:52 ` Eric Dumazet
2010-10-04 14:24 ` Jarek Poplawski [this message]
2010-10-04 15:21 ` Eric Dumazet
2010-10-05 7:24 ` David Miller
2010-10-05 7:31 ` Eric Dumazet
2010-10-02 12:10 ` [PATCH net-next V2] " jamal
2010-09-29 20:27 ` [PATCH net-next2.6] net: rename netdev rx_queue to ingress_queue David Miller
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