Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: FIND THE DIFFERENCE IN BOOK:

Author: Robert Hyatt

Date: 06:46:28 10/28/03

Go up one level in this thread


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.

OK...  How is that going to distribute hash space across all processors?  IE
I simply do one big malloc() for the hash table and another for the pawn
hash table.  If I have N threads, does it try to distribute a malloc() across
all processors?  If so, then it would seem that the recent changes you/I have
been working on to make split blocks allocate in local memory would also fail
as they would get distributed, but not in a way I can predict and not in a
way that is compatible with the new split-block handling code I did for the
NUMA version...

Am I missing something (probably so).  Also, for anyone asking, we are talking
about windows NUMA on AMD opterons.  I have not yet tweaked this for Linux
although the code is there.


>
>Thanks,
>Eugene



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.