Re: [PATCH 1/1][PKT_CLS] Avoid multiple tree locks

[David Miller <davem@davemloft.net>]

From: Patrick McHardy <kaber@trash.net>
Date: Thu, 22 Mar 2007 12:36:17 +0100

> jamal wrote:
> > The mutex is certainly a cleaner approach;
> > and a lot of the RCU protection would go away. I like it.
> 
> Not as much as I initially thought, but at least we would have
> consistent locking for the dump callbacks.
> 
> > Knowing you i sense theres something clever in there that i am 
> > missing. I dont see how you could get rid of the tree locking
> > since we need to protect against the data path still, no?
> > Or are you looking at that as a separate effort?
> 
> We can remove qdisc_tree_lock since with this patch all changes
> and all tree walking happen under the RTNL. We still need to keep
> dev->queue_lock for the data path.
> 
> I'll update the patches to include all rtnetlink users and repost
> in a day or two.

The existing weird "first SKB only" locking is unintuitive to
me as well, so I'm all for these mutex patches once you respin
them FWIW.