[mvapich-discuss] Cannot utilize CPU core

[Dhabaleswar Panda]

You are seeing the effect of `affinity' of processes to cores here. Try to
run your jobs with VIADEV_USE_AFFINITY=0. More details on this are
available from MVAPICH 1.1 user guide at the following location:

http://mvapich.cse.ohio-state.edu/support/mvapich_user_guide-1.1.html#x1-1340009.6.5

Let us know if the problem goes away with this option.

Also note that MVAPICH2 has many more flexible ways to bind processes to
cores. You can use the latest version of MVAPICH2 (1.4.1) to take
advantage of these features.

DK



On Tue, 30 Mar 2010, MORRIS LAW wrote:

> Dear all,
>
> I am new to the discussion group.
>
> Recently I found a problem of running mvapich 1.1 on Gen2-IB device (Qlogic 9120).  When subsequent run of mvapich job was delivered to the nodes, the later jobs will not run on free CPU cores but will compete with the current running CPU cores.  Thus the whole node cannot be utilized.  I don't know where the problem is.  Is it related to the IB switch or some parameter when I built the mvapich 1.1?
>
> I built mvapich 1.1 using gcc 4.1 on CentOS 5.3.  I have also built another version of mvapich 1.1 using icc and ifort on the same CentOS 5.3.  Both run jobs having similar problem.
>
> Would someone give me some hints to tackle the problem?
>
> Thanks in advance.
>
> --
> Morris Law
> HK Baptist University
>
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