[petsc-dev] configuring hypre on batch system

[Abhyankar, Shrirang G.]

Mark,
  The input for -threadcomm_affinities are the processor numbers

So -threadcomm_nthreads 4
     -threadcomm_affinities 0 1 2 3

will pin the 4 threads to processors 0,1,2,3. Unfortunately, there is no standardization of processor number mapping on physical and/or logical cores (it is decided by the OS I think). For example, on one node with two quad-core CPUs (total 8 processors, no hyperthreading), the 1st CPU may have processor numbers 0,1,3,5, while the other 2,4,6,8. On another node with similar hardware, the processor numbers may be 0,1,2,3 on the 1st CPU and 4,5,6,7 on the second. Hence, tools like likwid or hwloc are very helpful for getting the hardware layout. You may also obtain this info by looking at /proc/cupinfo on linux.

Shri
From: Mark Adams <mfadams at lbl.gov<mailto:mfadams at lbl.gov>>
Date: Thu, 8 Jan 2015 21:43:30 -0500
To: barry smith <bsmith at mcs.anl.gov<mailto:bsmith at mcs.anl.gov>>
Cc: petsc-dev mailing list <petsc-dev at mcs.anl.gov<mailto:petsc-dev at mcs.anl.gov>>
Subject: Re: [petsc-dev] configuring hypre on batch system


> -threadcomm_affinities 0 1 2 3 4 5 6 7  ?????

I    don't know what the flag is here


Neither do I.  The web page http://www.mcs.anl.gov/petsc/features/threads.html says:


  *
-threadcomm_affinities <list_of_affinities>: Sets the core affinities of threads

I'm not sure what to put here ...


> -threadcomm_type openmp
>
> Then would I get threaded MatVec and other CG + MG stuff?  I know this will not be faster but I just need data to corroborate what we all know.  And I don't care about setup.

  Depends on the smoother, we don't have any threaded SOR, if you using Jacobi + Cheyby it will be threaded.


Oh right, thanks,



-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-dev/attachments/20150109/00602927/attachment.html>