Hi, Andy and Leo, thanks for your replies.
Is it possible to get this new implementation? I would to give it a try. Regards, Stephan Am 31.05.2012 um 17:48 schrieb Yuanxin Liu <leo....@kitware.com>: > Hi, Stephan, > The previous implementation only has serial performance: It traces the > streamlines one at a time and never starts a new streamline until the > previous one finishes. With communication overhead, it is not surprising it > got slower. > > My new implementation is able to let the processes working on different > streamlines simultaneously and should scale much better. > > Leo > > > On Thu, May 31, 2012 at 11:27 AM, Andy Bauer <andy.ba...@kitware.com> wrote: > Hi Stephan, > > The parallel stream tracer uses the partitioning of the grid to determine > which process does the integration. When the streamline exits the subdomain > of a process there is a search to see if it enters a subdomain assigned to > any other processes before figuring it whether it has left the entire domain. > > Leo, copied here, has been improving the streamline implementation inside of > VTK so you may want to get his newer version. It is a pretty tough algorithm > to parallelize efficiently without making any assumptions on the flow or > partitioning. > > Andy > > > On Thu, May 31, 2012 at 4:16 AM, Stephan Rogge <stephan.ro...@tu-cottbus.de> > wrote: > Hello, > > I have a question related to the parallelism of the stream tracer: As I > understand the code right, each line integration (trace) is processed in an > own MPI process. Right? > > To test the scalability of the Stream tracer I've load a structured > (curvilinear) grid and applied the filter with a Seed resolution of 1500 and > check the timings in a single and multi-thread (Multi Core enabled in PV > GUI) situation. > > I was really surprised that multi core slows done the execution time to 4 > seconds. The single core takes only 1.2 seconds. Data migration cannot be > the explanation for that behavior (0.5 seconds). What is the problem here? > > Please see attached some statistics... > > Data: > * Structured (Curvilinear) Grid > * 244030 Cells > * 37 MB Memory > > System: > * Intel i7-2600K (4 Cores + HT = 8 Threads) > * 16 GB Ram > * Windows 7 64 Bit > * ParaView (master-branch, 64 bit compilation) > > ################################# > Single Thread (Seed resolution 1500): > ################################# > > Local Process > Still Render, 0.014 seconds > RenderView::Update, 1.222 seconds > vtkPVView::Update, 1.222 seconds > Execute vtkStreamTracer id: 2184, 1.214 seconds > Still Render, 0.015 seconds > > ################################# > Eight Threads (Seed resolution 1500): > ################################# > > Local Process > Still Render, 0.029 seconds > RenderView::Update, 4.134 seconds > vtkSMDataDeliveryManager: Deliver Geome, 0.619 seconds > FullRes Data Migration, 0.619 seconds > Still Render, 0.042 seconds > OpenGL Dev Render, 0.01 seconds > > > Render Server, Process 0 > RenderView::Update, 4.134 seconds > vtkPVView::Update, 4.132 seconds > Execute vtkStreamTracer id: 2193, 3.941 seconds > FullRes Data Migration, 0.567 seconds > Dataserver gathering to 0, 0.318 seconds > Dataserver sending to client, 0.243 seconds > > Render Server, Process 1 > Execute vtkStreamTracer id: 2193, 3.939 seconds > > Render Server, Process 2 > Execute vtkStreamTracer id: 2193, 3.938 seconds > > Render Server, Process 3 > Execute vtkStreamTracer id: 2193, 4.12 seconds > > Render Server, Process 4 > Execute vtkStreamTracer id: 2193, 3.938 seconds > > Render Server, Process 5 > Execute vtkStreamTracer id: 2193, 3.939 seconds > > Render Server, Process 6 > Execute vtkStreamTracer id: 2193, 3.938 seconds > > Render Server, Process 7 > Execute vtkStreamTracer id: 2193, 3.939 seconds > > Cheers, > Stephan > > > _______________________________________________ > Powered by www.kitware.com > > Visit other Kitware open-source projects at > http://www.kitware.com/opensource/opensource.html > > Please keep messages on-topic and check the ParaView Wiki at: > http://paraview.org/Wiki/ParaView > > Follow this link to subscribe/unsubscribe: > http://www.paraview.org/mailman/listinfo/paraview > >
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