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Subject: Re: compiling crafty

Author: Dave Gomboc

Date: 08:21:16 09/16/99

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On September 16, 1999 at 05:07:52, David Blackman wrote:

>On September 15, 1999 at 09:00:08, Robert Hyatt wrote:
>
>
>>But it is improving bit by bit.  Tim Mann suggested a new hashing scheme that
>>is cute for SMP users, as it effectively eliminates the Lock()/UnLock() calls
>>without the danger of incorrect hash results.
>
>This is not at all difficult and i'm pretty sure a few programs have been doing
>it for years. It get's a bit harder if you rely on the (shared) hash table to do
>detection of repetitions, or to count how many CPUs are currently active below a
>given node (some parallel algorithms rely on knowing this).
>

It's possible, but there are at least a couple of heavily parallel programs that
simply don't lock the entries and hope they don't get burned.

>But then, lock/unlock are not extremely slow on most modern hardware if you use
>inline assembler and avoid using system calls. Maybe a problem for the fast/dumb
>brigade.

Dave



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