Hi, Although I have no experience with parallel programming, I have to study the advantage of parallelization of one numerical integration method. First, I learned myself about parallel programming and I considered two alternatives : OpenMP and MPI. Finally, I have used an OpenMP because it is simple.
I have read some documents about Chapel and I like your goals. I hope I will take time to understand better parallel programming and to learn programming in Chapel for a future project. Thank you for your help. Mikel 2015-09-30 0:03 GMT+02:00 Brad Chamberlain <[email protected]>: > > Hi Mikel -- > > Tom's right that we don't have much free time this week, but a few things > in your message stuck out for me: > > * Increasingly, Chapel's single-node performance is competitive with > C+OpenMP. For a good OpenMP implementation and computation that fits > OpenMP well, I believe it would be challenging for Chapel to outperform > OpenMP. So I think your reasons for moving to Chapel for a scenario > like this would need to be "I want to take advantage of the productivity > and expressiveness features of Chapel" rather than "I want to create > something that outperforms my existing OpenMP code. Put another way, > if OpenMP isn't hampering you, Chapel may not be a win. > > * If you wanted to move to a distributed memory execution, that may be > a reason to move to Chapel since OpenMP can only target shared memory > and accelerators. Whether or not Chapel would give you good performance > in this setting will depend a lot on the characteristics of your > computation... > > * You mention quad precision arithmetic, which is something that Chapel > does not support at present. We discussed adding it early in the > project's history, but at that time, it was difficult to predict > how support for quad precision might vary across machines, so we left > it out for the time being. I suspect adding it in would not be > terribly complicated for a back-end C compiler with good support for > it, but I mostly wanted to emphasize that it is not available today. > > Hope this is helpful, > -Brad > > > > On Tue, 29 Sep 2015, Tom MacDonald wrote: > > Hi Mikel, >> >> The Chapel team is racing toward a release this week and >> it might take us a few days to respond. We appreciate your >> interest and Chapel and ask for a little patience. >> >> Best wishes, >> >> Tom MacDonald >> Chapel Manager >> >> On Tue, 29 Sep 2015, Mikel Antoñana wrote: >> >> Hi, >>> >>> I have developed an numerical integration algorithm in language C and I >>> ask >>> myself if I should programme it in Chapel to get better performance. >>> Next, >>> I give a short description of the algorithm. >>> >>> A huge number of integration steps are taken. >>> Only a small part of the code can be evaluated in parallel (I have used >>> Open MP model) and the ?fun? evaluation is expensive. >>> The units of work to run in parallel is small (p.e ns=6), so I carry >>> out >>> the computation in a multicore desktop. >>> I need to increase the accuracy of the solution and in the next future, >>> I >>> will make some computations using quadruple precision arithmetic. >>> >>> >>> Algorithm >>> >>> for k=1 to steps >>> { >>> ..... >>> # pragma omp parallel for >>> num_threads(thread_count) private(isn) >>> >>> for (is = 0; is<ns; is++) >>> { >>> isn=neq*is; >>> fun >>> (neq,u,&z[isn],&fz[isn],params,thestatptr); >>> } >>> ..... >>> } >>> >>> >>> I thank you sincerely your opinion. >>> >>> >>> Regards, >>> Mikel. >>> >>> >>> >>> >>> >>> >>>
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