Calling all performance experts! Here's you chance to become part of mathematics history contributing to the finding of one of the rarest things known to man... Mersenne Primes (there are currently only 44 known to exist). Refer: http://en.wikipedia.org/wiki/Mersenne_prime
How does this relate to OpenSolaris? Well OpenSolaris is involved in this years Google Summer of Code (GSoC)... Refer: http://www.opensolaris.org/os/project/summerofcode/students/ One of the projects is the FFT project which basically is about leveraging OpenSolaris for it's incredible scalability, cross platform support and most importantly it's observability and performance tools as a showcase for it's usefulness in highly threaded / HPC computing. To date we have taken what was a single threaded 'C' application 'Mlucas', added coarse grained parallel code (using OpenMP) to the majority of the program (there are a few minor components still being worked on) and compiled using the latest SunStudio12 C compiler. This has resulted in significant scalability as shown below... Sparc64 VI (2.13Ghz x 8 CPU (16 core)) - 1 thread = 106 secs - 2 threads = 55 secs (x 1.93) - 4 threads = 31 secs (x 3.42) - 8 threads = 18 secs (x 5.89) We are still a couple of days away from getting the application to be able to usefully employ 16 threads, however assuming even modest improvement beyond 8 threads, it will result in a new world record for the verification of Mersenne Primes. Currently at 8 threads on the Sparc64 VI it would take over 7.5 days to do the calculations for just one exponent. There are only 5 weeks left of the GSoC program and we now need to look at further tuning the software particularly for OpenSolaris on the Sparc & x64 architectures. What I require is for those on this list with performance experience to provide a little help in removing any system bottlenecks that might be there. This is actually not a large task as the application is only bound by CPU and real memory. There is no network activity, a tiny amount of disk I/O occurs once every 30+ secs, the application uses less than 100MB of real memory and is pretty much all integer calculations. So I only need help with CPU/Memory (particularly cache) performance. Basic checks have been made for cpu utilization, trapstat & context switching issues etc but we really need to bring in a bit more knowledge into the team. Ideally what I would like is for someone just to take 1-2 hours and give it the once over in terms of, are there any obvious wins that we have missed, which may include pointing us to the right Dtrace scripts to use for ongoing analysis. The Mlucas application is actually VERY simple in terms of processing and should be easy to analyze. There are four steps: - transform - square - inverse transform - carry These steps currently (at 8 threads) collectively take 0.018 secs to complete and then they run again and again (about 36million times). Thus ANY performance improvement makes a big difference as anything * 36 million equals something significant. So my request is.... if you may have the skills we are after please contact me and I can provide more information (an initial inquiry will not be treated as your guarantee of further commitment!). We can provide you with whatever you need and if you are in the Bay Area all the better as we could arrange for a physical meet with the main developer. Our two main developers are VERY smart cookies, we are just a little short on OpenSolaris observability/performance expertise. One benefit to OpenSolaris as a whole, is that this tuning will be including in the case study I'm writing up showcasing OpenSolaris as a great environment in which to do highly threaded / HPC type development. It should also result in OpenSolaris being the infrastructure that is used to verify the EFF prizewinning 10+million digit 45th Mersenne Prime (when it is found) resulting in additional media attention for OpenSolaris especially within the math and HPC sciences arenas. Many thanks, Rob Giltrap OpenSolaris - Google Summer of Code Mentor. _______________________________________________ perf-discuss mailing list perf-discuss@opensolaris.org
