On Thu, 19 Feb 2009 00:23:45 +0100 Patrick McHardy <kaber@xxxxxxxxx> wrote: > David Miller wrote: > > From: Patrick McHardy <kaber@xxxxxxxxx> > > Date: Wed, 18 Feb 2009 10:56:45 +0100 > > > >> Eric already posted a patch to use an array of locks, which is > >> a better approach IMO since it keeps the size of the conntrack > >> entries down. > > > > Just as a side note, we generally frown upon the > > hash-array-of-spinlocks approach to scalability. > > > > If you need proof that in the long term it's suboptimal, note that: > > > > 1) this is Solaris's approach to locking scalability :-) > > :) > > > 2) every such case in the kernel eventually gets transformed into > > RCU, a tree/trie based scheme, or some combination of the two > > > > So maybe for now it's ok, but keep in mind that eventually > > this is certain to change. :) > > This case might be different in that a normal firewall use case > probably doesn't have more than 16 cpus, even than would be quite > a lot. So for bigger machines this is probably more about keeping > the "non-use" costs low. > > I'll keep it in mind though and I'm interested in seeing how it > turns out in the long term :) It doesn't help that spinlock_t keeps growing! In good old days, a spin lock could fit in one byte. -- 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
