Re: [OMPI users] Avoiding the memory registration costs by having memory always registered, is it possible with Linux ?

Would be the use of mlockall helpful for this approach? From: Audet, Martin Sent: Monday, June 20, 2016 11:15 PM To: mailto:us...@open-mpi.org Subject: Re: [OMPI users] Avoiding the memory registration costs by having memory always registered, is it possible with Linux ? Thanks Jeff for your

Re: [OMPI users] Avoiding the memory registration costs by having memory always registered, is it possible with Linux ?

Thanks Jeff for your answer. It is sad that the approach I mentioned of having all memory registered for user process on cluster nodes didn't become more popular. I still believe that such an approach would shorten the executed code path in MPI libraries, reduce message latency, increase the co

Re: [OMPI users] memory cg '(null)'

Hi Rizwan, If you need to rewrite your fork system calls, you may want to check out mpi's spawn functionality. I recently found out about it and it's really useful if you haven't heard of it already. I am using it through python's mpi4py and it seems to be working well. Best, Jason Jason Maldoni

Re: [OMPI users] memory cg '(null)'

There is no guarantee that will work on a multiple mode job. tcp should be fine, infiniband might not work. the best way to be on the safe side is you rewrite your MPI app so it does not invoke the fork system call. this is generally invoked directly, or via the "system" subroutine. Cheers, Gill

Re: [OMPI users] memory cg '(null)'

Hi Gilles, Thanks for the support. :) This is a test which I am running on a single node, but I am intending to run calculations on multiple nodes. You mean it wouldn't work on multiple nodes? If I run on multiple nodes, how can I avoid these errors then? I would just test it for multiple node

[OMPI users] memory cg '(null)'

There are two points here 1. slurm(stepd) is unable to put the processes in the (null) cgroup. at first glance, this looks more of a slurm jus configuration 2. the MPI process forking. though this has a much better support than in the past, that might not always work, especially with fast interc

[OMPI users] memory cg '(null)'

Dear MPI users, I am getting the errors below while submitting/executing following script, #!/bin/sh #SBATCH -p short #SBATCH -J layers #SBATCH -n 12 #SBATCH -N 1 #SBATCH -t 01:30:00 #SBATCH --mem-per-cpu=2500 #SBATCH --exclusive #SBATCH --mail-type=END #SBATCH --mail-user=rizwan.ah...@aalto.fi #