Am Dienstag, den 30.08.2011, 10:48 -0600 schrieb John Peterson: > It will be extremely slow if it goes into swap. > > > Would this option just work with the existing code or do I have to > > change to ParallelMesh? > > Should work with existing code. Hopefully. >
> > > > – SMP mode : 4 GB of physical memory available to the MPI task > > running on each node (4 cores/node) > > I can't tell if you mean 4GB/node or 4GB/core. If it's the latter (16 > GB/node) then I don't see how you can possibly be running into swap. > If it's the former then there could be an issue. > > > For testing and learning I only use a partition of 32 nodes. > > 32 nodes or 32 cores? I don't know the details of your cluster so it > may be obvious, but make sure you aren't accidentally running too many > MPI processes on a given node. > As far as I understood it it is: 1 node = 4cores 4GB/node For testing and learning I only used a partition of 32 nodes. I have just changed to 128 nodes but this doesn't change anything. If I am running into swap and I use --enable-parmesh this wouldn't change much, (since I have one copy of the mesh per mpi-process), right? > > On Linux/UNIX systems, top is a program that prints what processes are > currently running, the relative amount of CPU they are using, and > their memory consumption. If you can access the compute node where > your code is running and see how much memory/CPU each of its processes > is consuming, you can get some idea if the code is running into swap > (there will be a very low CPU utilization and a very high memory > consumption). > top - 20:19:21 up 35 days, 8:55, 51 users, load average: 0.01, 0.29, 0.45 Tasks: 399 total, 1 running, 397 sleeping, 1 stopped, 0 zombie Cpu(s): 0.0%us, 0.2%sy, 0.0%ni, 99.7%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Mem: 31985140k total, 31158420k used, 826720k free, 274980k buffers Swap: 8393952k total, 160k used, 8393792k free, 16572876k cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 2955 bodner 16 0 3392 1932 1244 R 1 0.0 0:00.69 top 6602 bodner 15 0 14296 3248 1864 S 0 0.0 0:10.11 sshd 2829 bodner 15 0 19604 3892 3092 S 0 0.0 0:00.17 mpirun . . . The last one is the process of interest. ------------------------------------------------------------------------------ Special Offer -- Download ArcSight Logger for FREE! Finally, a world-class log management solution at an even better price-free! And you'll get a free "Love Thy Logs" t-shirt when you download Logger. Secure your free ArcSight Logger TODAY! http://p.sf.net/sfu/arcsisghtdev2dev _______________________________________________ Libmesh-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/libmesh-users
