[Users] update new user guide for non-TeraGrid/XSEDE users?

[Erik Schnetter]

On Wed, Aug 24, 2011 at 9:47 AM, Ian Hinder <ian.hinder at aei.mpg.de> wrote:
>
> On 24 Aug 2011, at 15:32, Erik Schnetter wrote:
>
>> On Wed, Aug 24, 2011 at 3:36 AM, Ian Hinder <ian.hinder at aei.mpg.de> wrote:
>>>
>>> On 23 Aug 2011, at 21:29, Erik Schnetter wrote:
>>>
>>>> Brian
>>>>
>>>> Cactus uses certain software packages (C compiler, Fortran compiler,
>>>> MPI, queuing system) which differ on basically every HPC system.
>>>> Instructions for building Cactus are therefore either targeted to a
>>>> specific system, or have to say "please read the system's
>>>> documentation to figure out these things". There is nothing in
>>>> particular that makes our instructions target TeraGrid systems; in
>>>> fact, we are targeting LONI systems, which are not part of XSEDE.
>>>>
>>>> If you follow the instructions at
>>>> <https://docs.einsteintoolkit.org/et-docs/Tutorial_for_New_Users>,
>>>> then these should work almost as is on Hopper. The are two
>>>> differences:
>>>> 1. You have to leave out the "soft add +git" since git is available by default.
>>>> 2. Since Hopper has 24 cores per node, you need to use a multiple of
>>>> 24 cores when submitting a job. Use "--procs=48" instead of
>>>> "--procs=32". You can also add "--num-threads=6" if you want to use
>>>> OpenMP as well (which should work out of the box).
>>>
>>> Should we have a section in the tutorial with information like this for each of the machines we know how to use?
>>
>> Should we change SimFactory to do this automatically (as default) when
>> OpenMP is enabled?
>
>
> I wasn't referring to this specifically.  I meant "Should we have a section in the tutorial which explains what is needed for each machine to run the ET?".
>
> Regarding OpenMP, I would like to have at least an option to always use the number of threads per process specified by num-threads in the machine's ini file.  At the moment, that variable is not used as far as I know.  What do you mean by "openmp is enabled"?  SimFactory always compiles with OpenMP, doesn't it?  The reason not to use more than 1 thread by default is that codes which don't support openmp will run several times more slowly.

OpenMP is enabled or disabled in the option list; Simfactory can look
at this for a particular configuration.

-erik

-- 
Erik Schnetter <schnetter at cct.lsu.edu>   http://www.cct.lsu.edu/~eschnett/