Author: Vincent Diepeveen
Date: 11:51:30 09/25/02
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On September 25, 2002 at 11:49:25, Russell Reagan wrote: Windows doesn't work at all above 64 processors AFAIK. Linux doesn't work above 8 processors AFAIK. But i'm looking for a cheap solution under linux now too and i see nowhere at manual pages of linux an example of how to do it. basically this is THE big problem under linux. MSDN under windows however shows about 100 examples how to do WaitForSingleObject. Of course other solutions to do the job are fine too here. I know under unix that the pthread libraries have something called pthread_cond_wait. this is a great function, but i can't use it, as my program is SMP, so SYMMETRIC MULTIPROCESSING. It means that all processors are equal. It means that any processor might terminate a certain iteration as last one. This one has to signal the i/o thread, which is a thread from some other process most likely (big chance with 512 processors). The current idea for linux is to sleep for 5 milliseconds and checkout whether an iteration has finished. So that's a possible waste of about 4 milliseconds times n moves (can be 50 or so), so that's losing each ply 0.2 seconds. if you get in endgame 11 ply out of hashtable that's 11 x 0.2 = 2.2 seconds. That is a big waste of seconds in a 1 0 game for example online at a dual k7. >On September 25, 2002 at 08:10:06, Vincent Diepeveen wrote: > >>i cannot use select() at all as i limit myself to < 128 processor >>partitions then. > >Does WaitForSingleObject or WaitForMultipleObjects allow you to use more than >128 processors? > >>also i have no idea how to get it to work and whether it can do >>it 400 times a second instantly. > >See the problems Microsoft causes? They always have to be different (in a bad >evil kind of way).
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