Hi Dave,
On Wed, Mar 14, 2012 at 10:38 AM, david collins
Hi--
Sorry for being sparse with the information, I should have been much more clear. This was running in parallel, 64 cores on Nautilus. The field was Density vs. MassFraction, MassFraction being a field I wrote that in this instance returns simply CellMass. lazy_reader is True. The run is 512^3 with 4 levels by 4, with only about 100 subgrids, but was written in 2007 (? i think) without parallel root grid IO on. My suspicion (without really understanding how yt parallelism works) is that each task needed to read in the root grid, rather than using the domain decomposition (?)
64 cores, using 12GB on each? That's a problem. MassFraction it sounds like has a handful of dependencies -- CellMassMsun, which depends on Density and dx, but dx should be used as a single value not as a field. So that gives 3*512^3*64 bits = 3 gigabytes, but that's a far cry from 12 gb/core. Plus, the domain decomp for profiles is per-grid -- so only one of your cores should get assigned the root grid. This is very bizarre.
Would lazy_reader off change things?
Yes, but it would make them worse. :) -Matt
Thanks, d.
Are you running in parallel? Which fields are you profiling? Do they have lots of dependencies, or require ghost zones? Is yt using lazy_reader? Does your data have many grids?
Matt
On Mar 14, 2012 12:37 AM, "david collins"
wrote: I should add that this was done on 64 cores-- in serial it works fine, just slow.
On Tue, Mar 13, 2012 at 9:35 PM, david collins
wrote: Hi, all--
I have an old dataset that I'm trying to make profiles on. It's a 512^3 root grid, but was written with ParallelRootGridIO off. I find that it's using strange amounts of memory, more than 12 Gb. Is this a known problem with a straight forward work-around?
d.
-- Sent from my computer.
-- Sent from my computer. _______________________________________________ yt-dev mailing list yt-dev@lists.spacepope.org http://lists.spacepope.org/listinfo.cgi/yt-dev-spacepope.org
_______________________________________________ yt-dev mailing list yt-dev@lists.spacepope.org http://lists.spacepope.org/listinfo.cgi/yt-dev-spacepope.org
-- Sent from my computer. _______________________________________________ yt-dev mailing list yt-dev@lists.spacepope.org http://lists.spacepope.org/listinfo.cgi/yt-dev-spacepope.org