[mvapich-discuss] mpiexec/mvapich places processes on same cpu

[Joseph Hargitai]

Sure, we'll try. I thought it was only an mvapich2 only option. We have .9, so we'll see. 

While we are at it - is there an actual way to assign with either version to specific cores? We have a few large multinode obs that can only use 4 out of 8 cores per node due to bus and memory limitations. Is there a way to distribute the processes to cores 1,2 and 5,6 ? ie to skip 0, and split the other 4 to different chips? 

j

----- Original Message -----
From: LEI CHAI <chai.15 at osu.edu>
Date: Friday, January 18, 2008 7:00 pm
Subject: Re: [mvapich-discuss] mpiexec/mvapich places processes on same cpu

> Hi Joseph,
> 
> Could you try disable the cpu affinity feature in mvapich/mvapich2, e.g.
> 
> mvapich2:
> $ mpiexec -n 4 -env MV2_ENABLE_AFFINITY 0 ./a.out
> 
> or mvapich:
> $ mpirun_rsh -np 4 VIADEV_ENABLE_AFFINITY=0 ./a.out
> 
> Thanks,
> Lei
> 
> 
> ----- Original Message -----
> From: Joseph Hargitai <joseph.hargitai at nyu.edu>
> Date: Friday, January 18, 2008 6:05 pm
> Subject: [mvapich-discuss] mpiexec/mvapich places processes on same cpu
> 
> > 
> > 
> > hi all:
> > 
> > While submitting two identical mpi jobs (-np 4) with differetnt 
> > datasets for a dual socket quadocore node using two distinct 
> > pbs/mpiexec submission both jobs end up on the first processor, 
> > such they use 4 cores of the first cpu, none of the second. This 
> > results in 8 processes on cpu 1, with a load of about 8-9, both 
> > jobs producing output okay, but obviously the choice would be to 
> > have them on distinct cpus. 
> > 
> > When one of these mpi jobs meet 4 others regular serial jobs 
> > submitted without mpiexec, all 8 cores are populated. 
> > 
> > I did read on the group list about the first mpiexec session being 
> > the master, but not reserving the first 4 cores such allowing the 
> > possibility for the next mpi job to end up on the same cpu. 
> > 
> > best,   
> > joseph
> > _______________________________________________
> > mvapich-discuss mailing list
> > mvapich-discuss at cse.ohio-state.edu
> > http://mail.cse.ohio-state.edu/mailman/listinfo/mvapich-discuss
> > 
>