Re: [PATCH RFC 1/2] netfilter: conntrack: remove RCU usage inconntrack notifier
From: Eric Dumazet
Date: Fri Apr 27 2012 - 14:59:03 EST
On Fri, 2012-04-27 at 14:28 -0400, Benjamin Poirier wrote:
> I think that the rcu usage in this code is pointless. It should either be
> removed or, if it was intended to protect against something, it ought to make
> that clear.
>
> 1) The code does not make use of the deferred deletion/wait for completion rcu
> api (ie. synchronize_rcu(), call_rcu()).
> 2) It does not benefit from the barriers implied by the rcu primitives used.
> The code deals with callback pointers. There's no need to order writes to the
> function code (!) before writes to the function pointers here.
> ---
At a first glance, this seems pretty wrong.
code can disappear under you, thats for sure.
CONFIG_NF_CT_NETLINK=m
hint : module unload contains an rcu barrier.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/