MPI_Init alllocates massive amounts of memory

[JakobFilser]

I am trying to run an MPI application compiled with mpiifort

ifort (IFORT) 2021.6.0 20220226

using mpiexec.hydra

Intel(R) MPI Library for Linux* OS, Version 2021.6 Build 20220227 (id: 28877f3f32)

on a machine with 36 cores

Intel(R) Xeon(R) Platinum 8360Y CPU @ 2.40GHz

Here is a minimal example program:

program test
implicit none 
integer :: mpi_err

include "mpif.h"

call MPI_INIT(mpi_err)
call MPI_FINALIZE()

end program

When calling MPI_INIT, massive amounts of memory (tens of GB) are allocated. The amount seems to increase with the number of cores. With more than 30 cores, MPI crashes because it runs out of memory.

[HemanthCH_Intel]

Hi,

Thanks for posting in Intel Communities.

>>"When calling MPI_INIT, massive amounts of memory (tens of GB) are allocated. The amount seems to increase with the number of cores."

Could you please let us know how you are checking the memory consumption used by the MPI_INIT?

Thanks & Regards,

Hemanth

[JakobFilser]

Hi,

thanks for your response. I get the load from the Xfce4 Systemload plugin https://docs.xfce.org/panel-plugins/xfce4-systemload-plugin/start

Best

Jakob

[HemanthCH_Intel]

Hi,

We are investigating your issue at our end and will get back to you soon.

Thanks & Regards,

Hemanth

[HemanthCH_Intel]

Hi,

Could you please provide the steps to install the Xfce plugin and also let us know if there are any dependencies?

Thanks & Regards,

Hemanth.

[JakobFilser]

Hi,

unfortunately I do not know this either. I got the computer from my employer with the OS (and desktop environment, of which xfce is part) already installed. Sorry about this.

Thanks for your efforts and best

Jakob

[HemanthCH_Intel]

Hi,

In the above post, we can see that you are using include "mpif.h". It is not recommended to use "mpif.h".By using APS we can see the memory consumed by the program attached is less than 300MB.

By using the below commands, you can find the memory consumed by mpi application:

mpiifort hello_mpi.f90
export MPS_STAT_LEVEL=5
mpirun -n 2 aps -c mpi ./a.out
The above command will generate the aps_result_<date> file
aps --report /home/intel/hemanth/mpi_threads/fortran/latest/aps_result_20220617 
The above command will generate the time,memory consumed by the application. It also generates the HTML file.

For more information refer to the below link:

https://www.intel.com/content/www/us/en/develop/documentation/get-started-with-application-performance-snapshot/top.html

Thanks & Regards,

Hemanth

[HemanthCH_Intel]

Hi,

We haven't heard back from you. Could you please provide an update on your issue?

Thanks & Regards,

Hemanth

[HemanthCH_Intel]

Hi,

We assume that your issue is resolved. If you need any additional information, please post a new question as this thread will no longer be monitored by Intel.

Thanks & Regards,

Hemanth