Author: Vincent Diepeveen
Date: 12:53:36 12/04/00
Go up one level in this thread
On December 04, 2000 at 15:46:14, Robert Hyatt wrote:
>On December 04, 2000 at 15:33:51, Vincent Diepeveen wrote:
>
>>On December 04, 2000 at 15:25:34, Eugene Nalimov wrote:
>>
>>>On December 04, 2000 at 15:09:37, Vincent Diepeveen wrote:
>>>
>>>>On December 04, 2000 at 14:58:17, Andrew Dados wrote:
>>>>
>>>>>On December 04, 2000 at 14:53:02, Bo Persson wrote:
>>>>>
>>>>>>On December 04, 2000 at 14:43:06, Andrew Dados wrote:
>>>>>>[...]
>>>>>>>Dear Ernst.
>>>>>>>
>>>>>>>First I find your post (and many past ones) of very little merit, just 'flagrant
>>>>>>>commercial exhortations' at best. Second you can't ask everyone to read your
>>>>>>>book to understand what you mean if you can't write it clearly in few lines. And
>>>>>>>finally I fail to see what part of Vincents post was utter nonsense.
>>>>>>>
>>>>>>>-Andrew-
>>>>>>
>>>>>>Hey!
>>>>>>
>>>>>>The book is also his thesis. Maybe it is difficult to give a half page summary
>>>>>>of several year's work!
>>>>>
>>>>>Maybe... But giving same answer for each problem ('Go buy my book!') suggests
>>>>>something else to me.
>>>>>-Andrew-
>>>>
>>>>Let's not try to imagine what happens when he would have had a
>>>>commercial program.
>>>
>>>So you have a commercial program?
>>
>>What is 'he' referring to in the above sentence?
>>
>>>>Note that i used about 184mb RAM in 3 different caches with EGTB
>>>>information stored.
>>>> - 150mb transpositionhashtable ==> i store EGTB there too in a special way
>>>
>>>So it is not exclusively EGTB cache, right?
>>
>>of course not. also transpositiontable but with some obvious
>>additions to let it perform better for egtb.
>>
>>>> - 2x2mb egtb cache
>>>> - 2x15 mb wasted for just the egtb indices as i'm dual processor.
>>>
>>>Trash. There is only one set of EGTB cache and indices, regardless of number of
>>>CPUs, at least in the code I wrote.
>>
>>I'm multiprocessor, please explain me how!
>>
>>I only saw some multiTHREADING code.
>>
>>There is a small but existing difference between the 2.
>
>
>Eugene doesn't know that you aren't using threads... you are creating
>new processes with nothing shared except what you explicitly share via
>shmget()/shmat(). I don't think that is the way to do this on an SMP
>machine, but that is your choice, of course. And with the way you have
>implemented things, there _are_ 4 copies of the cache, since your processes
>don't share everything implicitly as is done using threads.
>That is one of many disadvantages...
First of all multiprocessing is faster as multithreading. I can tell you
some horror multithreading stories about windows if you want to.
Secondly Eugene could have remembered as i several times posted it,
also emailed it to him asking how to fix it. That's been some time ago
i guess perhaps forgotten therefore.
Sharing the indices using multiprocessing is indeed not very easy.
I see no disadvantages towards multiprocessing, as it saves me
from a pointer which you need but i don't need. For clusters
or running over the network i see advantages, but under linux for
sure it's a disadvantage as not only this problem needs to be
solved.
In windows multiprocessing sure is a major advantage over multithreading,
but i only start to realize that pretty recently after having huge
problems with threads and GUI.
If you do something in the GUI which is doing graphical things,
then it seems windows is blocking all other threads of the process.
>
>
>>
>>>Eugene
>>>
>>>>Note i probe also in the qsearch which most people don't do. I initially
>>>>didn't do it either but then started drawing some games on the internet
>>>>because i didn't do it.
>>>>
>>>>But for sure i don't want to waste another 16mb RAM from the expensive
>>>>RAM i have now for another EGTB cache.
>>>>
>>>>Instead more likely is that i convert the EGTB to my own format after
>>>>which users who usually don't have an additional 15mb for egtb indices
>>>>to let them do without.
>>>>
>>>>>>
>>>>>>I have read the book and found it very interesting, full of new information and
>>>>>>a very good buy.
>>>>>>
>>>>>>
>>>>>>
>>>>>>BoPersson
>>>>>>bop@malmo.mail.telia.com
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