On 19/12/2016 07:58, Marco Atzeri wrote:
> On 18/12/2016 15:55, Bahadır Öncel wrote:
>> Hello all!
>> I've installed cygwin and openmpi successfully. I can compile and run
>> mpi programs. Twist is, even the openmpi test program hello_c.c approx
>> takes a minute to run. When I try in my virtual machine (linux) the
>> same program takes less than a second to run.
>> I've found that other users asked the same question but did not find
>> any solution.
>> Thanks in advance.
>>
>> --
>
> the most likely issue is a network interface timeout.
> Try disabling WIFI network or VPN interface as test.
>
> Regards
> Marco
>

Hi Bahadır,
this is the normal behaviour of the hello_c run on my machine.

$ time mpirun -n 2 ./hello_c.exe
Hello, world, I am 0 of 2, (Open MPI v1.10.4, package: Open MPI , ident: 
1.10.4, repo rev: v1.10.3-45-gaafbd34, Sep 01, 2016, 129)
Hello, world, I am 1 of 2, (Open MPI v1.10.4, package: Open MPI , ident: 
1.10.4, repo rev: v1.10.3-45-gaafbd34, Sep 01, 2016, 129)

real    0m3.428s
user    0m1.293s
sys     0m2.930s

The timing should be in the second range.


Attached a program that will allow you to identify all the
network interfaces as seen by Cygwin with their Windows name.

$ gcc -o get-interface get-interface.c

$ ./get-interface
internal_name:  {EC2ABB5C-42A8-431D-A133-8F4BE0F309AF}
  flags:         AF_INET6 up multicast
  address:       fe80::a479:1393:b7d0:fb25%18
  friendly_name: Local Area Connection 2

internal_name:  {EC2ABB5C-42A8-431D-A133-8F4BE0F309AF}
  flags:         AF_INET  up broadcast multicast
  address:       169.254.251.37
  friendly_name: Local Area Connection 2
...and so on.