Hello, okay, if you want to you can read through the code [1]. :) For comparation it includes the program in C which I successfully parallelized with MPI and the same program in Chapel. I hope I didn't forget to comment important lines. If anything is unclear just ask me.
Please consider the code won't win a beauty contest (especially the one in C) but at least my Chapel code is more readable than the code in C mostly written by the responsible employee. ;) bye [1] http://www-user.tu-chemnitz.de/~michd/fish.tar.gz Zitat von Lydia Duncan <[email protected]>: > Hi Michael, > > I think it will be difficult for us to offer further suggestions > without looking at the code ourselves, would you be comfortable > sending it? > > Lydia > > On 08/18/2014 05:27 AM, Michael Dietrich wrote: >> Hello, >> >> today I compiled my program with the --fast flag. >> Though it made both the serial execution much faster than before, the >> parallel one became even slower compared with the serial. I'm still >> trying to find any possible mistakes within my code but I can't find >> any. Any suggestions? >> >> bye >> >> >> >> Zitat von Tom MacDonald <[email protected]>: >> >>> Hi Michael, >>> >>> Without --fast the compiler generates runtime checks, which slows >>> down execution time. >>> >>> Please compile with the --fast flag and see how much execution >>> time improvement there is. >>> >>> Thanks >>> >>> Tom MacDonald >>> >>> On Fri, 15 Aug 2014, Tom MacDonald wrote: >>> >>>> Hi Michael, >>>> >>>> Thank you for your interest in Chapel! It's good to hear you are >>>> studying high performance programming languages. >>>> >>>> Are you compiling your Chapel program with the --fast option? >>>> >>>> We need to know that before looking deeper. >>>> >>>> Thanks >>>> >>>> Tom MacDonald >>>> >>>> On Fri, 15 Aug 2014, Michael Dietrich wrote: >>>> >>>>> Hello, >>>>> >>>>> I'm working with Chapel due to my bachelor thesis about high >>>>> performance programming languages. My current task is to implement a >>>>> particle simulation program of which I already have the code in C. It >>>>> includes two possible algorithms for calculating the force acting onto >>>>> the particles: A simple but ineffective one and the >>>>> Barnes-Hut-Algorithm [1] which is much faster but a bit more >>>>> complicated. The other calculations aren't that complex so for me only >>>>> the calculation of force is important. >>>>> >>>>> I implemented the simple algorithm at first. For comparing the serial >>>>> and parallel execution time I surrounded everything with a >>>>> serial-statement, evaluating a bool variable I have to set in the >>>>> command line. I didn't implement the multi locale improvement yet so >>>>> it runs only on a dual core PC, using forall-loops. Finally the >>>>> parallel one only needed half of the time of the serial, yay. >>>>> >>>>> I continued with Barnes-Hut. This one was a bit more work because the >>>>> maintenance of the tree-structure leaves a lot of opportunities for >>>>> mistakes. After a bit more time it was working as well. >>>>> My issue is about the parallel execution time of this algorithm. Like >>>>> in the other one I replaced the crucial for-loop with a forall-loop >>>>> (the serial-statement surrounds the whole program). The problem is, >>>>> that the parallel execution time is similar to the serial one, >>>>> sometimes even longer. >>>>> Of course I don't want you to read through all my code, but could you >>>>> tell me some possible reasons, why this effect may occur? >>>>> >>>>> thank you very much >>>>> bye >>>>> Michael >>>>> >>>>> >>>>> [1] http://beltoforion.de/barnes_hut/barnes_hut_en.html >>>>> >>>>> >>>>> ------------------------------------------------------------------------------ >>>>> _______________________________________________ >>>>> Chapel-users mailing list >>>>> [email protected] >>>>> https://lists.sourceforge.net/lists/listinfo/chapel-users >>>>> >>>> ------------------------------------------------------------------------------ >>>> _______________________________________________ >>>> Chapel-users mailing list >>>> [email protected] >>>> https://lists.sourceforge.net/lists/listinfo/chapel-users >>>> >> >> >> >> ------------------------------------------------------------------------------ >> _______________________________________________ >> Chapel-users mailing list >> [email protected] >> https://lists.sourceforge.net/lists/listinfo/chapel-users ------------------------------------------------------------------------------ _______________________________________________ Chapel-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/chapel-users
