Mersenne: Prime search on SMP Linux
I'd like to search for Mersenne primes on my SMP Linux box. Info on the search is at: http://www.mersenne.org/prime.htm Machine is a dual Celeron 466, 256 megs. It is my server, basically single-user, powered up 24/7 and I'm not there all time. RedHat 6.1, 2.2.x kernel. I'd like to run one copy of the search code in such a way that it monopolises one CPU, in hopes it will succeed relatively quickly. Is there a way to do that? I'd also like to run a second copy at low priority, set up so it will not interfere with either the primary prime searcher or anything else I want to do with the machine. I'm assuming here that there's no multi-threading in the search code, that it would not be useful to try and run one search using both CPUs. Is that accurate? _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: Prime search on SMP Linux
Hi Sandy, At 11:41 AM 1/3/00 -0500, Sandy Harris wrote: I'd like to run one copy of the search code in such a way that it monopolises one CPU, in hopes it will succeed relatively quickly. Is there a way to do that? Yes. Run mprime -m and choose Advanced/Priority. Enter a value of 9 instead of the default value of 1. Now let me explain why you don't want to do that. Assume the other tasks you run every day require 1000 CPU seconds. No matter what priority you run mprime at there are only 2*86400 - 1000 CPU seconds available. Raising mprime's priority will slow down the other tasks but not improve mprime's throughput at all. I'm assuming here that there's no multi-threading in the search code, that it would not be useful to try and run one search using both CPUs. Is that accurate? You are correct. Run one mprime with no arguments and run the second mprime with the "-A1" argument. Hope that helps, George _ Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
