-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 12-01-31 03:08 PM, Watson Ladd wrote: > On Tue, Jan 31, 2012 at 1:46 PM, David Goulet <[email protected]> wrote: > Hi everyone, > > To help the tor project, I'll contribute some of my spare time to improve > multithreading for the Tor code base. >> Color me confused: This is for taking advantage of multiprocessor >> systems, correct?
Yep :) > I've speak a bit with Nick M. and it seems the crypto lib is an important part > to begin with. The wiki page > (https://trac.torproject.org/projects/tor/wiki/org/projects/Tor/MultithreadedCrypto) > indicates, basically, that a worker thread pool with a work queue to dispatch > crypto events should be the right approach and I do agree. > > Is it acceptable to link an external library to the project being a > dependence? > > The library I'm thinking about is "liburcu" which stands for user-space RCU > (http://lttng.org/urcu). It's a complete set of lockless data structure > including wait-free queue which can be very useful for our case. It support a > large variety of architecture and works on BSD and Linux. The Linux kernel use > RCU mechanism for a lot of internal data structure today so it's quite tested > and solid. >> One future issue I foresee is the use of batching oriented crypto >> operations. If we use binary Edwards curves for speed in the onion >> skins, then batching becomes a major timesaver. The obvious way to do >> this is with workers grabbing and putting back batches, but we also >> want to maintain responsiveness. If a router is getting low traffic it >> shouldn't wait forever to fill up a batch. Indeed. Adding latency to a node is just a no go I think so definitely things to consider. Thanks! David > > The question I think is do we want lockless data structure in Tor or it's not > and will not be necessary for the type of workload ? (lockless re-sizable hash > tables, red-black tree, stack, linked-list (double also) and queue are > available > as of today). > > Waiting on your feedback guys, either way, I'll begin implementing parallel > crypto largely based on the wiki page (really good ideas there). > > Thanks a lot! > David _______________________________________________ tor-dev mailing list [email protected] https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-dev > Sincerely, > Watson Ladd -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) iQEcBAEBAgAGBQJPKJr1AAoJEELoaioR9I02ymsH/1/30lIjE6UF/lEOxDWdGQp7 JDE9bE6ggoHN8Os/Uuw8Xe6ggE8p7ywbz6ofq+kXZn9PA299gwcH2jtNAa2/Ht9s 3smWlLJkcsNFMx7IXSapictXL1wAV/Mpo7HwmutT3BKRynhwNTmExzutSuEavROD BN4OUV/3YmhFqwOqkvbA5ohNNHBss+BKrRjeeK+LmyP6o4tLYl1tjdMFP+y5Pol5 NoTM0nW2SS0cVA5GssfBbJyTqBsvOQF6JB5y17VhpPz7yGbK5C4qx1VsfQ9jAoZv U2BRaMxVMVtwQrxgk5YFhMGoXEBgTAEp2hG2EsSsE18M9v/R9tHBoIwSkDkAnrM= =IvNp -----END PGP SIGNATURE----- _______________________________________________ tor-dev mailing list [email protected] https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-dev
