On Aug 1, 2010, at 2:32 PM, mohammed elsaeedy wrote: > Dear David, > > > Thank you for your reply, but does that mean the traditional PGAS > programming language does not present Intra-level parallelism (as in > threads)? and it only provides Inter-level parallelism as in executing on > different Processing Elements. > Where as APGAS, provides both level of parallelism. > > am I right?
Correct. APGAS environments (in theory) make it easier to program multi-level parallel applications. As hybrid architectures become more common (think clusters of multicore nodes or clusters of nodes each containing an accelerator like a GPU), multilevel parallelism will be necessary to fully utilize the machine. Of course, multilevel parallelism can be created outside of APGAS: lots of programmers are combining MPI + OpenMP or MPI + CUDA. Dave > I hope I get my other questions answered too :) > > Thank you all > > On Sun, Aug 1, 2010 at 1:55 PM, Dave Hudak <dhu...@osc.edu> wrote: > >> >> On Aug 1, 2010, at 7:47 AM, mohammed elsaeedy wrote: >> >>> Dear List, >>> >>> I have some questions regarding PGAS and X10, >>> >>> 1) One of the goals for PGAS languages is: >>> *One-sided communication for improved inter-process performance, *how is >>> that achieved, if I'm compiling with an x10rt of MPI flavor, which is >>> eventually a *Two**-sided communication.* >>> * >>> * >>> *2)How is the "async" implemented under the hoods? is it POSIX threads or >> is >>> it OpenMP?* >>> * >>> * >>> *3) X10 and Chapel are APGAS, what is the difference between APGAS and >> PGAS >>> langauges? >> >> I'll try this one. APGAS is shorthand for "asynchronous PGAS". >> Traditional PGAS implementations (UPC and Co-Array FORTRAN) use an >> MPI-style execution called SPMD (single-program, multiple data) in which a >> fixed number of parallel threads are created at the beginning of the program >> and all exist until the end of the program. In asynchronous PGAS, the >> programmer can create threads during the execution of the program (e.g., >> using the async or at commands in X10). >> >> Thanks, >> Dave >> >>> * >>> -- >>> Thank you for your concern. >>> Regards, >>> Mohammed El Sayed >>> >> ------------------------------------------------------------------------------ >>> The Palm PDK Hot Apps Program offers developers who use the >>> Plug-In Development Kit to bring their C/C++ apps to Palm for a share >>> of $1 Million in cash or HP Products. Visit us here for more details: >>> http://p.sf.net/sfu/dev2dev-palm >>> _______________________________________________ >>> X10-users mailing list >>> X10-users@lists.sourceforge.net >>> https://lists.sourceforge.net/lists/listinfo/x10-users >> >> --- >> David E. Hudak, Ph.D. dhu...@osc.edu >> Program Director, HPC Engineering >> Ohio Supercomputer Center >> http://www.osc.edu >> >> >> >> >> >> >> >> >> >> >> >> ------------------------------------------------------------------------------ >> The Palm PDK Hot Apps Program offers developers who use the >> Plug-In Development Kit to bring their C/C++ apps to Palm for a share >> of $1 Million in cash or HP Products. Visit us here for more details: >> http://p.sf.net/sfu/dev2dev-palm >> _______________________________________________ >> X10-users mailing list >> X10-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/x10-users >> > > > > -- > Thank you for your concern. > Regards, > Mohammed El Sayed > ------------------------------------------------------------------------------ > The Palm PDK Hot Apps Program offers developers who use the > Plug-In Development Kit to bring their C/C++ apps to Palm for a share > of $1 Million in cash or HP Products. Visit us here for more details: > http://p.sf.net/sfu/dev2dev-palm > _______________________________________________ > X10-users mailing list > X10-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/x10-users --- David E. Hudak, Ph.D. dhu...@osc.edu Program Director, HPC Engineering Ohio Supercomputer Center http://www.osc.edu ------------------------------------------------------------------------------ The Palm PDK Hot Apps Program offers developers who use the Plug-In Development Kit to bring their C/C++ apps to Palm for a share of $1 Million in cash or HP Products. Visit us here for more details: http://p.sf.net/sfu/dev2dev-palm _______________________________________________ X10-users mailing list X10-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/x10-users
