[GRASS-dev] openMP support in GRASS GIS

[Anna Petrášová]

Hi,

yes I already changed the r.sim.sediment, so it is running there, I
just wanted to check there is no theoretical issue since you haven't
mentioned it in the paper. I kept the max number of walkers lower as
it was, the problem if I remember correctly is that is uses static
allocations, so if we raise it, it will take a lot of memory. So that
would need to be rewritten. Perhaps you should create a ticket about
that error, to keep track of it. Thank you

On Thu, Aug 24, 2017 at 3:38 PM, Jaro Hofierka <jhofierka at gmail.com> wrote:
> Hi Anna,
>
> many thanks! Please keep it in addons for a while, as it is referenced in
> the paper. Yes it is possible to use it in r.sim.sediment as well because
> actually we have parallelized the simulation library (simlib) used by
> r.sim.sediment as well. But it needs some modification of Makefile and
> main.c to include openMP. Otherwise it runs without OpenMP.
> Also please note that I have changed the maximum number of walkers in
> waterglobs.h to 20 million from 7 million. This might be needed to compute
> large grids, but the simulation algorithm should be checked because
> sometimes it reports error (nwalk > maxw) when assigns walkers (this is not
> related to openMP).
>
> Best wishes,
>
> Jaro
>
> Anna Petrášová napísal(a):
>
>> Dear Jaro and all,
>>
>> During recent code sprint in Boston I ported r.sim.water.mp to GRASS
>> r.sim.water and r.sim.sediment. I tested it with r.sim.sediment and it
>> seems to work, so let me know if there are any reasons parallelization
>> shouldn't be used with r.sim.sediment. I removed all the commented
>> parts which you probably put there during experimenting. I didn't
>> remove the version in addons, because you have it linked in your
>> paper, but maybe we should put a note in the r.sim.water.mp manual,
>> that the latest version is in the core? As for r.sun, when I have
>> time, I will look at it.
>>
>> Anna
>>
>> On Sat, Aug 5, 2017 at 4:24 AM, Jaro Hofierka <jhofierka at gmail.com> wrote:
>>>
>>> Hi Markus,
>>>
>>> This is just a small contribution and I would like acknowledge help of
>>> reviewers to improve the manuscript. I believe more such grass-based
>>> papers
>>> in scientific journals will further promote GRASS within the wider
>>> scientific community.
>>> Of course, we would welcome if this could go to the trunk version. Vaclav
>>> helped us is v.surf.rst and it is already there and I hope he could also
>>> help with r.sim.water and r.sun. He can contact me or my colleagues and
>>> we
>>> will provide any assistance.
>>>
>>> Best wishes,
>>>
>>> Jaro
>>>
>>> Markus Neteler napísal(a):
>>>
>>>> Hi,
>>>>
>>>> just saw that this article got published (congrats, Jaro and team):
>>>>
>>>> Hofierka, J., Lacko, M., Zubal, S., 2017. Parallelization of
>>>> interpolation, solar radiation and water flow simulation modules in
>>>> GRASS GIS using OpenMP. Computers & Geosciences.
>>>> doi:10.1016/j.cageo.2017.07.007
>>>>
>>>> Questions: since the code is already in addons, how about merging the
>>>> changes into trunk?
>>>>
>>>> Markus
>>>>
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>>
>>
>