[yt-dev] Parallelization & the ART frontend

Christopher Moody cemoody at ucsc.edu
Wed Feb 8 13:09:02 PST 2012


Hi Matt,

pf.h.proj is of type <class 'yt.data_objects.hierarchy.AMRQuadTreeProj'>
and refine_by is 2.

Does this help? I'm not sure what you mean by overlaps -  doesn't the the
RAMSES grid patching mechanism produce non-overlapping grids from the octs?
Is quadtree proj checking for overlapping grids?

chris

On Wed, Feb 8, 2012 at 12:44 PM, Matthew Turk <matthewturk at gmail.com> wrote:

> Hi Chris,
>
> Yeah, that's weird.  My guess is that load balancing is going haywire
> for some reason, likely due to overlap versus quadtree proj.  Can you
> tell me what type of object pf.h.proj is?  i.e., what's the output of
> "print pf.h.proj"?  And then, what's pf.refine_by?
>
> -Matt
>
> On Wed, Feb 8, 2012 at 3:00 PM, Christopher Moody <cemoody at ucsc.edu>
> wrote:
> > Hi Matt,
> >
> > I've got the log output here:http://paste.yt-project.org/show/2153/with the
> > serial version here http://paste.yt-project.org/show/2154/ .
> >
> > The most interesting tidbit is below, where it looks like core 0 projects
> > Levels 0-5 and core 1 projects Level 6 (which takes up like 99% of the
> > projection time.)
> >
> > chris
> >
> > P001 yt : [DEBUG    ] 2012-02-08 11:39:53,403 Going to obtain []
> > P001 yt : [DEBUG    ] 2012-02-08 11:39:53,406 Preloading ['density']
> from 0
> > grids
> > P001 yt : [DEBUG    ] 2012-02-08 11:39:53,406 End of projecting level
> level
> > 0, memory usage 3.545e-01
> > P001 yt : [DEBUG    ] 2012-02-08 11:39:53,406 Preloading ['density']
> from 0
> > grids
> > P001 yt : [DEBUG    ] 2012-02-08 11:39:53,406 End of projecting level
> level
> > 1, memory usage 3.545e-01
> > P001 yt : [DEBUG    ] 2012-02-08 11:39:53,407 Preloading ['density']
> from 0
> > grids
> > P001 yt : [DEBUG    ] 2012-02-08 11:39:53,407 End of projecting level
> level
> > 2, memory usage 3.545e-01
> > P001 yt : [DEBUG    ] 2012-02-08 11:39:53,408 Preloading ['density']
> from 0
> > grids
> > P001 yt : [DEBUG    ] 2012-02-08 11:39:53,408 End of projecting level
> level
> > 3, memory usage 3.545e-01
> > P001 yt : [DEBUG    ] 2012-02-08 11:39:53,408 Preloading ['density']
> from 0
> > grids
> > P001 yt : [DEBUG    ] 2012-02-08 11:39:53,408 End of projecting level
> level
> > 4, memory usage 3.545e-01
> > P001 yt : [DEBUG    ] 2012-02-08 11:39:53,409 Preloading ['density']
> from 0
> > grids
> > P001 yt : [DEBUG    ] 2012-02-08 11:39:53,409 End of projecting level
> level
> > 5, memory usage 3.545e-01
> > P001 yt : [DEBUG    ] 2012-02-08 11:39:53,409 Preloading ['density']
> from 6
> > grids
> > P001 yt : [INFO     ] 2012-02-08 11:39:53,410 Starting 'Projecting
>  level  6
> > /  6 '
> > P000 yt : [INFO     ] 2012-02-08 11:39:54,057 Finishing 'Projecting
>  level
> >  0 /  6 '
> > P000 yt : [DEBUG    ] 2012-02-08 11:39:54,057 End of projecting level
> level
> > 0, memory usage 4.482e-01
> > P000 yt : [DEBUG    ] 2012-02-08 11:39:54,057 Preloading ['density']
> from 1
> > grids
> > P000 yt : [INFO     ] 2012-02-08 11:39:54,058 Starting 'Projecting
>  level  1
> > /  6 'P000 yt : [INFO     ] 2012-02-08 11:39:54,070 Finishing 'Projecting
> >  level  1 /  6 '
> > P000 yt : [DEBUG    ] 2012-02-08 11:39:54,070 End of projecting level
> level
> > 1, memory usage 4.482e-01
> > P000 yt : [DEBUG    ] 2012-02-08 11:39:54,070 Preloading ['density']
> from 1
> > gridsP000 yt : [INFO     ] 2012-02-08 11:39:54,071 Starting 'Projecting
> >  level  2 /  6 '
> > P000 yt : [INFO     ] 2012-02-08 11:39:54,130 Finishing 'Projecting
>  level
> >  2 /  6 '
> > P000 yt : [DEBUG    ] 2012-02-08 11:39:54,130 End of projecting level
> level
> > 2, memory usage 4.482e-01
> > P000 yt : [DEBUG    ] 2012-02-08 11:39:54,130 Preloading ['density']
> from 1
> > grids
> > P000 yt : [INFO     ] 2012-02-08 11:39:54,131 Starting 'Projecting
>  level  3
> > /  6 '
> > P000 yt : [INFO     ] 2012-02-08 11:39:54,783 Finishing 'Projecting
>  level
> >  3 /  6 '
> > P000 yt : [DEBUG    ] 2012-02-08 11:39:54,784 End of projecting level
> level
> > 3, memory usage 4.482e-01
> > P000 yt : [DEBUG    ] 2012-02-08 11:39:54,784 Preloading ['density']
> from 1
> > grids
> > P000 yt : [INFO     ] 2012-02-08 11:39:54,784 Starting 'Projecting
>  level  4
> > /  6 '
> > P000 yt : [INFO     ] 2012-02-08 11:39:59,389 Finishing 'Projecting
>  level
> >  4 /  6 '
> > P000 yt : [DEBUG    ] 2012-02-08 11:39:59,389 End of projecting level
> level
> > 4, memory usage 5.918e-01
> > P000 yt : [DEBUG    ] 2012-02-08 11:39:59,389 Preloading ['density']
> from 1
> > grids
> > P000 yt : [INFO     ] 2012-02-08 11:39:59,389 Starting 'Projecting
>  level  5
> > /  6 '
> > P000 yt : [INFO     ] 2012-02-08 11:40:17,735 Finishing 'Projecting
>  level
> >  5 /  6 '
> > P000 yt : [DEBUG    ] 2012-02-08 11:40:17,735 End of projecting level
> level
> > 5, memory usage 1.569e+00
> > P000 yt : [DEBUG    ] 2012-02-08 11:40:17,735 Preloading ['density']
> from 0
> > grids
> > P000 yt : [DEBUG    ] 2012-02-08 11:40:17,736 End of projecting level
> level
> > 6, memory usage 1.569e+00
> > P001 yt : [INFO     ] 2012-02-08 11:41:31,681 Finishing 'Projecting
>  level
> >  6 /  6 '
> > P001 yt : [DEBUG    ] 2012-02-08 11:41:31,681 End of projecting level
> level
> > 6, memory usage 2.113e+00
> > P000 yt : [DEBUG    ] 2012-02-08 11:41:33,807 Opening MPI Barrier on 0
> > P000 yt : [INFO     ] 2012-02-08 11:41:34,502 Projection completed
> > P001 yt : [DEBUG    ] 2012-02-08 11:41:34,502 Opening MPI Barrier on 1
> > P001 yt : [INFO     ] 2012-02-08 11:41:34,502 Projection completed
> > P001 yt : [DEBUG    ] 2012-02-08 11:41:34,579 Opening MPI Barrier on 1
> >
> >
> >
> >
> > On Wed, Feb 8, 2012 at 6:46 AM, Matthew Turk <matthewturk at gmail.com>
> wrote:
> >>
> >> Hi Chris,
> >>
> >> On Tue, Feb 7, 2012 at 9:30 PM, Christopher Moody <cemoody at ucsc.edu>
> >> wrote:
> >> > Hi guys,
> >> >
> >> > I've been working hard on the ART frontend. Lately, I'm to the point
> >> > where
> >> > I'm playing around with more complex datasets that are taking much
> >> > longer to
> >> > project - so I'd really like to to start using the parallelization
> >> > engines.
> >> > I've tried Sam's workshop parallelization demos, and they all work.
> But
> >> > launching with the ART frontend (
> http://paste.yt-project.org/show/2152/)
> >> > spawns many independent processes which evidently are not actually
> >> > splitting
> >> > the projection job, but still taking up lots of processors.
> >>
> >> My guess is that parallelism is not enabled for the ART frontend
> >> simply as a matter of how the IO is conducted.  To make it really work
> >> in parallel, the IO needs to be split up so that when process 1 reads
> >> a given grid patch, the rest of the processors don't also need to read
> >> all the data for that grid patch.
> >>
> >> Can you lower your loglevel (by setting loglevel = 1 in ~/.yt/config
> >> or by --config yt.loglevel=1 on the command line) and report back with
> >> what it says during a projection job there?
> >>
> >> -MAtt
> >>
> >> >
> >> > My mpi installation  works:
> >> > yt : [INFO     ] 2012-02-07 18:12:28,207 Global parallel computation
> >> > enabled: 0 / 8yt : [INFO     ] 2012-02-07 18:12:28,207 Global parallel
> >> > computation enabled: 2 / 8
> >> > yt : [INFO     ] 2012-02-07 18:12:28,208 Global parallel computation
> >> > enabled: 1 / 8
> >> > yt : [INFO     ] 2012-02-07 18:12:28,208 Global parallel computation
> >> > enabled: 6 / 8
> >> > yt : [INFO     ] 2012-02-07 18:12:28,208 Global parallel computation
> >> > enabled: 3 / 8
> >> > yt : [INFO     ] 2012-02-07 18:12:28,208 Global parallel computation
> >> > enabled: 4 / 8
> >> > yt : [INFO     ] 2012-02-07 18:12:28,208 Global parallel computation
> >> > enabled: 5 / 8yt : [INFO     ] 2012-02-07 18:12:28,209 Global parallel
> >> > computation enabled: 7 / 8
> >> >
> >> > But the script is just run 8 times, not any faster.
> >> >
> >> > What am I missing here?
> >> >
> >> > Many thanks!
> >> > chris
> >> >
> >> > _______________________________________________
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> >> >
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