You have many independent runs, right? Why worry about multi-threading? Divide the set into (say) 16 threads (or whatever makes sense for your CPU) and run each set on another thread.
-Joseph On Mon, 17 Jun 2019 at 19:28, Øystein Schønning-Johansen <[email protected]> wrote: > Thanks for your input. I'm still thinking about this. > I really cannot decide which rollout code to use. :-) > > - sagnubg is really good but I have to tweak it a bit to make it work. I'm > also not sure it is multi-threading. > - GNU Backgammon, for sure it is good, but I probably have to build some > scripts to run this through. Indeed multi-threading seems to work. > - My own little rollout code. It really works good, but when I add > multi-threading with OpenMP, it really does not speed up at all. Getting > this working is actually what I'm spending time on now. I'm really > scratching my head. > > As you mention, the tool I posted some weeks ago can indeed be used for > some of the positions. That was actually the main reason I created the tool > in the first place. I think you are right. I have to start with the > positions with a lot of checkers born off. I can probably sort out in a > simple way. I should also only handle positions where gammon and backgammon > are not a subject. I can probably handle those separately. > > -Øystein > > On Sun, Jun 16, 2019 at 10:33 PM Philippe Michel <[email protected]> > wrote: > >> On Mon, Jun 10, 2019 at 02:49:26PM +0200, Øystein Schønning-Johansen >> wrote: >> >> > I will try re-rolling out these positions. Do you have any experience of >> > how to do good rollouts of race positions? Good rollout settings for >> race >> > positions? >> >> When I re-rolled out the benchmarks I mostly used the settings that had >> been used previously. I think I changed the rolloutLimit parameter >> somehow (the number of alternatives included for checker plays). It is >> currently set to 10 for doublets and 5 for other rolls. I don't remember >> exactly what I did ; maybe it used to be 5 in all cases. >> >> I previously wrote it would be useful to have variance reduction in >> sagnubg, but this is not very important since it does 0-plys rollouts >> (VR works for them, but it is slow and simply doing more trials is about >> as good in terms of SD vs. time used). Doing 7776 trials instead of 1296 >> doesn't seem unrealistic. >> >> From the other parameters : >> >> s version 1.93 weights 1.00 moves2plyLimit 20 rolloutLimit 5 >> nRollOutGames 1296 cubeAway 7 include0Ply 1 evalPlies 2 shortCuts 1 >> osrGames 1296 osrInRoll 1 >> >> experimenting with osrInRoll set to 0 may be interesting. I dont know if >> OSR >> is used for speed or for accuracy... >> >> Another interesting thing to try, if it is practical, would be to use the >> software you mentionned a few weeks ago to calculate exact values. >> >> For instance, sort the positions by leading player's pipcount. Start >> from the smallest ones with your software ; that should tackle the >> hypergammon-like positions with few checkers and ideally the very >> unbalanced ones where the trailer can only try to save the gammon. The >> latter may well be misplayed in the current rollouts. >> > _______________________________________________ > Bug-gnubg mailing list > [email protected] > https://lists.gnu.org/mailman/listinfo/bug-gnubg >
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