[mvapich-discuss] truly one-sided communication

[Thiago Ize]

Hi Sreeram,
Scattering some iprobes in my code roughly doubled my programs 
performance in certain situations.  Unfortunately, since my code is kind 
of random with the communication, occasionally there will already be too 
many MPI calls taking place such that performance is impacted and then 
the additional iprobes don't help at all.  I guess 1.7 will solve most 
of these issues, but until then this will have to do.

Thanks for the help!
Thiago

sreeram potluri wrote:
> Dear Thiago,
>
> I you can spare a thread, making it call MPI_iProbe on a dummy tag 
> will help progress in the background. From your description, we think 
> that process 0 is the source and is computation intensive. In this 
> case having an extra thread at this process should not have a negative 
> impact. However, you will have to initialize MPI with MPI_THREAD_MULTIPLE.
>
> MV2 uses process binding by default but in multi-threaded 
> environments, it is suggested to disable binding and let OS take care 
> of it. Please see this section of our user guide: 
>
> http://mvapich.cse.ohio-state.edu/support/user_guide_mvapich2-1.6rc2.html#x1-530006.12 
>
> Please let us know if this works and if you have any other questions.
>
> Sreeram Potluri
>