Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: The Tobacco fields of my youth -- Parallel algorithms

Author: Anthony Cozzie

Date: 09:06:10 02/26/04

Go up one level in this thread


On February 26, 2004 at 11:18:07, Charles Roberson wrote:

>
>   30 years ago, I spent time working for tobacco farmers. I dislike smoking of
>any kind but it was the only job in town. There were several things that we did
>that easily applies to parallel algorithms. These methods were all in how to
>help out the slower people and getting the field primed faster.
>
>  All rows were not of uniform length -- the fields had curved boundaries.
>  So, here were some of the things we tried.
>   1) When the fastest person finishes, he helps the next person closest to
>      finishing. Then, those two help the next person closest to finishing and
>      so on ....
>
>       Variation: When the #2 person is finished the two leaders help split
>                  their help across persons 3 and 4. Then the 4 split their
>                  help across persons 5,6,7,8.
>
>                  Once we had two or more helping the others "out". The
>                  fastest person helps the person farthest behind and so on.
>
>   2) When the first person finishes, he helps "out" the person the most
>      behind. Then second person out helps the new person the most behind.
>      If the person originaly farthest behind is not the second "out" due to
>      the help. The two split efforts to help the most behind.
>
>
>   Now, which was the most effective and which did the farmers like the most?
>   #1 was the most effective and most liked by the farmer.
>
>   Why?
>     1) it made it very clear who were the slackers. (an issue with comps??)
>     2) the slackers were often taught better techniques and thus sometimes.
>         if they still didn't improve they weren't rehired.
>     3) it was better for morale -- the good received some amount of help but
>         so did the bad. Also, the best performers did not do too much extra
>         work.
>
>     Now, how does this apply to comps. Are there slackers? Yes, what about
>     distributed systems with different speed processors.
>
>     The first algorithm reminds me of Young Brothers Wait -- the last nodes
>     helped are the ones move ordering designates as least best.
>
>     The second algorithm reminds me of Bob's paper on DTS or any other work
>     stealing approach.

I don't think DTS really suggested a split strategy (other than split at ALL
nodes if possible).  Bob's paper is more, "how can we design a parallel
structure so that we can split anywhere in the tree".  Once you have a working
DTS implementation, you can split however you want . . .

anthony



This page took 0 seconds to execute

Last modified: Thu, 15 Apr 21 08:11:13 -0700

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.