On Thu, 22 Feb 2007 03:07:55 -0800 (PST) David Miller <[EMAIL PROTECTED]> wrote:
> From: "Michael K. Edwards" <[EMAIL PROTECTED]> > Date: Thu, 22 Feb 2007 03:00:32 -0800 > > > Besides, RCUing a hash of any sort sounds like a nightmare, whereas > > something like a splay tree is reputed to be very straightforward to > > make "persistent" in the functional-programming sense. I haven't > > coded that one myself but surely it's in the current edition of Knuth. > > Knuth tends to be thorough, yet archaic. :-) > > > You are much better off obtaining all per-flow state with a > > single data structure lookup. It would be kind of nice if state for > > other layers like IPSec and NAT could live there too. > > This is the eventual idea. > > > By the way, are these flows unidirectional or bidirectional? > > The entries created by Robert's TRASH are unidirectional, they have to > be because the path from remote to localhost is different than the > path from localhost to remote :-) > > But we don't need to do a socket demux on packet output, we just > need a plain route (+ firewall, IPSEC, etc.) destination cache > entry for that. > - There are a number of other lock-less algorithms rather than simple RCU that might be worth exploring. A number of them rely on a working implementation of compare-exchange; that can be a problem since some architectures don't have a fast way of doing that. -- Stephen Hemminger <[EMAIL PROTECTED]> - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
