Search found 17077 matches

by bob
Wed Aug 29, 2007 10:01 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: re-inventing the SMP wheel
Replies: 81
Views: 38418

Re: re-inventing the SMP wheel

The problem is that the description of the state-of-the-art methods is either unduly long, or rather vague. The questions I am left with are mostly about implementation details, the various strategies are clear enough. E.g., if it says that a thread, finding a cut-move in a split point, has to abor...
by bob
Wed Aug 29, 2007 9:52 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Testing the waters for opening move
Replies: 6
Views: 2833

Re: Testing the waters for opening move

Hi all, I have created an opening book out of gm2600. Earlier my program exited from the opening phase with an inferior position at times, it did not understand how to proceed and did not recover. To beat this I now allow my program to search with the book move for a small time of about 1/5th of re...
by bob
Wed Aug 29, 2007 5:52 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Testing the waters for opening move
Replies: 6
Views: 2833

Re: Testing the waters for opening move

Hi all, I have created an opening book out of gm2600. Earlier my program exited from the opening phase with an inferior position at times, it did not understand how to proceed and did not recover. To beat this I now allow my program to search with the book move for a small time of about 1/5th of re...
by bob
Wed Aug 29, 2007 5:51 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Testing the waters for opening move
Replies: 6
Views: 2833

Re: Testing the waters for opening move

Hi all, I have created an opening book out of gm2600. Earlier my program exited from the opening phase with an inferior position at times, it did not understand how to proceed and did not recover. To beat this I now allow my program to search with the book move for a small time of about 1/5th of re...
by bob
Wed Aug 29, 2007 5:20 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: re-inventing the SMP wheel
Replies: 81
Views: 38418

Re: re-inventing the SMP wheel

Well, the main point is actually how best to do SMP search.. :? So far the idea of having the owner of split-nodes hand out a limited number of moves to would-be slaves via the hash bucket seems a nice way to do it. Only the polling to know if the current search should be aborted might become a pai...
by bob
Wed Aug 29, 2007 3:29 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: re-inventing the SMP wheel
Replies: 81
Views: 38418

Re: re-inventing the SMP wheel

Well, it isn't that bad, because usually the TLB misses are satisfied from L2. Usually the data misses L2 before you start missing the TLB, as manufacturers are careful to provide at least enough TLB entries to address all of L2. (I guess an increase of L2 size would hardly show up in the benchmark...
by bob
Tue Aug 28, 2007 11:29 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: re-inventing the SMP wheel
Replies: 81
Views: 38418

Re: re-inventing the SMP wheel

First, I though we were discussing this in the context of a chess engine, not in terms of general-purpose applications? I am not sure what you want to say with this. We are discussing the best way to do paging. For Chess programs you don't want to page at all. So in the context of a Chess program i...
by bob
Tue Aug 28, 2007 3:33 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: re-inventing the SMP wheel
Replies: 81
Views: 38418

Re: re-inventing the SMP wheel

The alternative is doing a _ton_ of I/O that is totally unnecessary. I'd rather swap out 2 4K pages out of 64 that were actually modified, rather than all 64 of them. Etc... If writing/reading the 64 pages takes as long, of 1% longer than reading/writing the single page, I would prefer writing the ...
by bob
Tue Aug 28, 2007 3:00 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: re-inventing the SMP wheel
Replies: 81
Views: 38418

Re: re-inventing the SMP wheel

What kind of logic is that? If 90% of everything you bring in is nonsense, it doesn't matter at all which page size you use. 256KB pages could only be bad if they would bring in a larger fraction of nonsense than 4KB pages. In particular that applies to the initial page-in, where you would just nee...
by bob
Tue Aug 28, 2007 2:47 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Frustrations of a mediocre chess programmer. What next?
Replies: 34
Views: 16424

Re: Frustrations of a mediocre chess programmer. What next?

PSWBTM does allow you to start from arbitrary positions: you just have to specify a file with the moves leading to them in PGN, or FENs, and your match uses those as initial position. I always run matches from the Nunn positions for testing. If the specified file contains 10 positions, and you ask ...