Comments on: Tic-tac-toe in Erlang — parallel processing http://nealabq.com/blog/2009/02/16/tic-tac-toe-in-erlang-parallel-processing/ Probing dark corners while dodging the grues Thu, 22 Jul 2010 01:02:34 +0000 hourly 1 http://wordpress.org/?v=3.0 By: Neal http://nealabq.com/blog/2009/02/16/tic-tac-toe-in-erlang-parallel-processing/comment-page-1/#comment-70 Neal Tue, 17 Mar 2009 17:21:30 +0000 http://nealabq.com/blog/?p=1008#comment-70 Thanks. I didn't know about +P. That'll be interesting to play with. Hmm, and I must not have 80,000 simultaneous process running, like I guessed. Maybe 30,000. And yes, these processes spend almost all their lives just waiting for cycles. I'm running this on a somewhat underpowered machine with only 2 cores and 1G memory. The massively parallel runs were a little slower (about 25%) than the serial runs. So spawning all those processes, although not terribly expensive, is still enough to use up any gains from having 2 cores. And I'm not even sure I'm using 2 cores. When I start the Erlang shell it says: Erlang (BEAM) emulator version 5.6.5 [smp:2] [async-threads:0] Does this mean everything is running in a single operating-system thread? Sounds like it. Thanks. I didn’t know about +P. That’ll be interesting to play with.

Hmm, and I must not have 80,000 simultaneous process running, like I guessed. Maybe 30,000.

And yes, these processes spend almost all their lives just waiting for cycles. I’m running this on a somewhat underpowered machine with only 2 cores and 1G memory.

The massively parallel runs were a little slower (about 25%) than the serial runs. So spawning all those processes, although not terribly expensive, is still enough to use up any gains from having 2 cores.

And I’m not even sure I’m using 2 cores. When I start the Erlang shell it says:

Erlang (BEAM) emulator version 5.6.5 [smp:2] [async-threads:0]

Does this mean everything is running in a single operating-system thread? Sounds like it.

]]> By: Nikolas Bowe http://nealabq.com/blog/2009/02/16/tic-tac-toe-in-erlang-parallel-processing/comment-page-1/#comment-69 Nikolas Bowe Mon, 16 Mar 2009 14:02:10 +0000 http://nealabq.com/blog/?p=1008#comment-69 Hi. This is an interesting series on tic-tac-toe in Erlang. Thanks. Whats the performance difference on your machine between the parallel version and the non parallel one for a board with 2 marks? In this example processes spend a lot of the time waiting, so I think you might be better off spawning fewer processes and making them do more work. Maybe only spawn processes for the 9 initial moves. Its not particularly intelligent and doesnt scale past 9 cores but its dead easy to implement. Note: You can increase the process limit by using the +P command line switch to erl. The default is 32768 processes. Hi. This is an interesting series on tic-tac-toe in Erlang. Thanks.

Whats the performance difference on your machine between the parallel version and the non parallel one for a board with 2 marks?

In this example processes spend a lot of the time waiting, so I think you might be better off spawning fewer processes and making them do more work. Maybe only spawn processes for the 9 initial moves. Its not particularly intelligent and doesnt scale past 9 cores but its dead easy to implement.

Note: You can increase the process limit by using the +P command line switch to erl. The default is 32768 processes.

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