Re: [OMPI users] kernel 2.6.23 vs 2.6.24 - communication/wait times

To keep this thread updated: After I posted to the developers list, the community was able to guide to a solution to the problem: http://www.open-mpi.org/community/lists/devel/2010/04/7698.php To sum up: The extended communication times while using shared memory communication of openmpi

Re: [OMPI users] kernel 2.6.23 vs 2.6.24 - communication/wait times

On 4/6/2010 2:53 PM, Jeff Squyres wrote: > > Try NetPIPE -- it has both MPI communication benchmarking and TCP > benchmarking. Then you can see if there is a noticable difference between > TCP and MPI (there shouldn't be). There's also a "memcpy" mode in netpipe, > but it's not quite the

Re: [OMPI users] kernel 2.6.23 vs 2.6.24 - communication/wait times

> However, reading through your initial description on Tuesday, none of these > fit: You want to actually measure the kernel time on TCP communication costs. > Since the problem occurs also on node only configuration and mca-option btl = self,sm,tcp is used, I doubt it has to do with TCP

Re: [OMPI users] kernel 2.6.23 vs 2.6.24 - communication/wait times

Hello, On Thursday 01 April 2010 12:16:25 pm Oliver Geisler wrote: > Does anyone know a benchmark program, I could use for testing? There's an abundance of benchmarks (IMB, netpipe, SkaMPI...) and performance analysis tools (Scalasca, Vampir, Paraver, Opt, Jumpshot). However, reading through

Re: [OMPI users] kernel 2.6.23 vs 2.6.24 - communication/wait times

You could try MPI Test Tool (MTT, http://www.open-mpi.org/projects/mtt/). 2010/4/2 Oliver Geisler > Does anyone know a benchmark program, I could use for testing? > > > -- > This message has been scanned for viruses and > dangerous content by MailScanner, and is > believed

Re: [OMPI users] kernel 2.6.23 vs 2.6.24 - communication/wait times

Does anyone know a benchmark program, I could use for testing? -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean.

Re: [OMPI users] kernel 2.6.23 vs 2.6.24 - communication/wait times

I have tried up to kernel 2.6.33.1 on both architectures (Core2 Duo and I5) with the same results. The "slow" results are also appearing for distribution of processes on the 4 cores one single node. We use btl = self,sm,tcp in /etc/openmpi/openmpi-mca-params.conf Distributing several process to

Re: [OMPI users] kernel 2.6.23 vs 2.6.24 - communication/wait times

I have a very dim recollection of some kernel TCP issues back in some older kernel versions -- such issues affected all TCP communications, not just MPI. Can you try a newer kernel, perchance? On Mar 30, 2010, at 1:26 PM, wrote: > Hello List, > > I

[OMPI users] kernel 2.6.23 vs 2.6.24 - communication/wait times

Hello List, I hope you can help us out on that one, as we are trying to figure out since weeks. The situation: We have a program being capable of slitting to several processes to be shared on nodes within a cluster network using openmpi. We were running that system on "older" cluster hardware