From: Ingo S. <ing...@tu...> - 2007-03-23 13:43:58
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My idea is to check the processor ID ((mesh.node(res_node_no-1)).processor_id()) of the result node and compare it with libMesh::processor_id() before writing the nodal data to the output file (using the previous version of ex8). Stupidly the processor ID of the node is 65536. Does libMesh actually assign the proc ID to the DofObject? regards Ingo Ingo Schmidt schrieb: > Hi, > > at first I was glad that the bug fix is working (i.e. compiling and > running the code in parallel) but yesterday I checked the benefit of > parallelisation. > The benefit is unfortunately is an impairment. Increasing the number of > CPU's slows down the computation time in a considerable measure. > E.g. > example 8: 1 CPU approx. 9 seconds > 2 CPU's approx. 14 seconds > > That's pretty bad... > > best regards > > Ingo > > Roy Stogner schrieb: > >> On Mon, 19 Mar 2007, Roy Stogner wrote: >> >> >>> I'll commit a fix to CVS this afternoon, but hopefully that's enough >>> info to get your own code back on track. >>> >> I may not be familiar enough with MPI or our NumericVector API, but I >> don't actually see how to write an efficient, simple fix. So, I've >> committed an inefficient and convoluted fix to CVS instead. >> >> I'll also see about making it more convenient to run these examples in >> parallel; I can't believe that nobody has ever run ex8 in parallel >> under METHOD=dbg before. My application Makefiles use a LIBMESHRUN >> environment variable to find my own "mpirun -whatever" invocation, and >> a LIBMESHOPTIONS environment variable to hold extra PETSc options to >> be added to the end of commands; if there aren't any objections, I'll >> make the example Makefiles check the same variables, so there will be >> at least one person regularly trying "make run_examples" in parallel. >> --- >> Roy >> > > -- Dipl.-Ing. Ingo Schmidt Institute of Modelling and Computation Hamburg University of Technology tel: +49/(0)40/42878-4483 Denickestr.17 fax: +49/(0)40/42878-4353 Building L/ room: 3032 e-mail: ingo.schmidt@TUHH.de 21075 Hamburg http://www.mub.TU-Harburg.de |