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Subject: Re: To Vasik - What is the progress of MP Rybka ?

Author: Vasik Rajlich

Date: 06:07:23 01/20/06

Go up one level in this thread


On January 19, 2006 at 18:41:30, Jay Urbanski wrote:

>On January 19, 2006 at 08:18:35, Vasik Rajlich wrote:
>
>>On January 19, 2006 at 03:48:34, Tord Romstad wrote:
>>
>>>On January 18, 2006 at 22:26:06, Jay Urbanski wrote:
>>>
>>>>On January 18, 2006 at 17:55:55, Dann Corbit wrote:
>>>>
>>>>>Executables are heavyweight processes that heavily consume resources and threads
>>>>>are lightweight processes which consume less resources.  But a threaded server
>>>>>needs any global variables to have write-access gated with a critical section
>>>>>whereas a global in a spawned server has no effect (since each server is a
>>>>>single process running a single thread of execution).
>>>>>
>>>>>It is better, but much harder, to write a threaded chess engine.
>>>>
>>>>
>>>>Very true but with nearly all processor improvements in the immediate future
>>>>coming from more cores/threads - it will likely be worth the effort to bite the
>>>>bullet and learn to write good threaded code at some point.
>>>
>>>Why?  Wouldn't a chess engine using multiple processes and
>>>shared memory be just as fast as a similar program with
>>>multiple threads on a computer with several CPUs (or CPUs
>>>with multiple cores)?  I thought the engine using processes
>>>would just consume a bit more memory, and not have any
>>>significant disadvantages apart from that.
>>>
>>>I'm not saying that you are wrong, of course.  I am totally
>>>ignorant about this subject, and I ask in order to learn more.
>>>
>>>Tord
>>
>>Dann and Jay are I guess talking about the mp implementation of just sharing the
>>hash table. It's a very cheap way to get some performance benefit, and I am
>>thinking about it as a lazy way out for the time being.
>>
>>Indeed I realize that multi-threaded apps are probably the future. It's just a
>>question of finding the time to do this (and taking this time away from other
>>tasks).
>>
>>Vas
>
>So, my $0.02 is that I'd prefer an SMP version sooner even if it's non-optimal,
>and you can take the time to a better job with it at your leisure. :)
>
>Idle CPUs seem like such a waste to me...

Yes, that's what I was thinking. There should at least be something very soon.

Vas



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