Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: parallel scaling

Author: Robert Hyatt

Date: 06:48:52 10/28/03

Go up one level in this thread


On October 27, 2003 at 21:23:13, Vincent Diepeveen wrote:

>On October 27, 2003 at 20:09:55, Eugene Nalimov wrote:
>
>>On October 27, 2003 at 20:00:54, Robert Hyatt wrote:
>>
>>>On October 27, 2003 at 19:57:12, Eugene Nalimov wrote:
>>>
>>>>On October 27, 2003 at 19:24:10, Peter Skinner wrote:
>>>>
>>>>>On October 27, 2003 at 19:06:51, Eugene Nalimov wrote:
>>>>>
>>>>>>
>>>>>>I don't think you should be afraid. 500 CPUs is not enough -- you need
>>>>>>reasonable good program to run on them.
>>>>>>
>>>>>>Thanks,
>>>>>>Eugene
>>>>>
>>>>>I would bet on Crafty with 500 processors. That is for sure. I know it is quite
>>>>>a capable program :)
>>>>>
>>>>>Peter.
>>>>
>>>>Efficiently utilizing 500 CPUs is *very* non-trivial task. I believe Bob can do
>>>>it, but it will be nor quick nor easy.
>>>>
>>>>Thanks,
>>>>Eugene
>>>
>>>
>>>If the NUMA stuff doesn't swamp me.  And if your continual updates to the
>>>endgame tables doesn't swamp me.  We _might_ see some progress here.  :)
>>>
>>>If I can just figure out how to malloc() the hash tables reasonably on your
>>>NUMA platform, without wrecking everything, that will be a step...
>>
>>Ok, just call the memory allocation function exactly where you are calling it
>>now, and then let the user issue "mt" command before "hash" and "hashp" if (s)he
>>want good scaling.
>>
>>Thanks,
>>Eugene
>
>That's why i'm multiprocessing. All problems solved at once :)


And several added.  Duplicate code.  Duplicate LRU egtb buffers.  Threads
are not necessarily bad here.  We're hitting 6.75M+ nodes per second on a quad
opteron at 1.8ghz.  That's not bad.  I'll post some output when everything is
cleaned up and finalized, particularly allocating the hash tables.



This page took 0 seconds to execute

Last modified: Thu, 15 Apr 21 08:11:13 -0700

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.