On Fri, 2009-04-17 at 01:07 -0700, David Miller wrote: > From: "Paul E. McKenney" <paulmck@xxxxxxxxxxxxxxxxxx> > Date: Thu, 16 Apr 2009 22:40:32 -0700 > > > I completely agree that this RCU is absolutely -not- 2.6.30 material. ;-) > > I don't understand why we're writing such complicated code. > > Oh I see why, it's because not every arch uses the generic SMP helpers > yet :-) > > Because if they did universally, we could solve this problem so > simply, by merely sending a remote softirq to every online cpu. Once > those all complete we have enough of a quiesce period, every cpu must > have exited any netfilter packet processing code path they were in. > > And we could know they complete using an atomic counter or something. Since its a full broadcast, we can do that _today_ using on_each_cpu(). But whatever way we turn this, this will be a very expensive operation. Imagine doing that on your 256-way for every iptables rules change. -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
