On Wed, Jun 8, 2016 at 3:41 PM Xujun Zhao <xzha...@gmail.com> wrote: > Hi Cody, > > This sounds like the mesh data keeps a copy on each processor, but the > matrices and vectors are still stored distributedly. is it correct? > > Yes
> I have a 3D stokes problem with 60x60x60 mesh, 2nd order element for > velocity u,v,w, and first order for pressure p. Totally about 2.9M dofs. > This can run with 1, 2 and 3 CPUs. However, if I use 4 CPUs, the program > crashed with segmentation fault as follows: > > If I run a smaller system, e.g. 25x25x25, it still works for 4 CPUs. Do > you think this is caused by memory due to the mesh duplication? > > That's a good size problem for a single machine. You may very well be running out of memory here. I'd suggest that you open up another window and watch the memory usage for your smaller problem, scale it up and watch it grow. You can always try switching to "DistributedMesh" to see if that helps. It will a little but it probably won't make as big of a difference as you might expect. It might be time to distribute your problem to a few nodes. Cody > > ==================================================================================== > > BAD TERMINATION OF ONE OF YOUR APPLICATION PROCESSES > > = PID 23903 RUNNING AT b461 > > = EXIT CODE: 9 > > = CLEANING UP REMAINING PROCESSES > > = YOU CAN IGNORE THE BELOW CLEANUP MESSAGES > > > =================================================================================== > > YOUR APPLICATION TERMINATED WITH THE EXIT STRING: Killed (signal 9) > > This typically refers to a problem with your application. > > Please see the FAQ page for debugging suggestions > > On Wed, Jun 8, 2016 at 4:17 PM, Cody Permann <codyperm...@gmail.com> > wrote: > >> That's right! >> >> This is the classic space versus time tradeoff. In the bigger scheme of >> things, using a little more memory is usually fine on a modern system. The >> SerialMesh (now called ReplicatedMesh) is quite a bit faster. I think the >> general consensus is: use ReplicatedMesh until you are truly memory >> constrained AND you know that the bulk of the memory is in your mesh and >> not your matrices and vectors and everything else. >> >> Cody >> >> On Wed, Jun 8, 2016 at 2:40 PM Xujun Zhao <xzha...@gmail.com> wrote: >> >>> Hi all, >>> >>> I am curious about SerialMesh running with multiple CPUs. If I have 1 >>> node >>> with 16 cores on the cluster. Will "mpirun -n 16" lead to 16 copies of >>> SerialMesh? If so, it looks like running on multiple CPUs will require >>> more >>> memory?? >>> >>> Thanks. >>> Xujun >>> >>> ------------------------------------------------------------------------------ >>> What NetFlow Analyzer can do for you? Monitors network bandwidth and >>> traffic >>> patterns at an interface-level. Reveals which users, apps, and protocols >>> are >>> consuming the most bandwidth. Provides multi-vendor support for NetFlow, >>> J-Flow, sFlow and other flows. Make informed decisions using capacity >>> planning reports. >>> https://ad.doubleclick.net/ddm/clk/305295220;132659582;e >>> _______________________________________________ >>> Libmesh-users mailing list >>> Libmesh-users@lists.sourceforge.net >>> https://lists.sourceforge.net/lists/listinfo/libmesh-users >>> >> > ------------------------------------------------------------------------------ What NetFlow Analyzer can do for you? Monitors network bandwidth and traffic patterns at an interface-level. Reveals which users, apps, and protocols are consuming the most bandwidth. Provides multi-vendor support for NetFlow, J-Flow, sFlow and other flows. Make informed decisions using capacity planning reports. https://ad.doubleclick.net/ddm/clk/305295220;132659582;e _______________________________________________ Libmesh-users mailing list Libmesh-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libmesh-users
