[yt-dev] Question regarding changeset 71c2bfaa3b5f in yt on ghostzone calculations

[Cameron Hummels]

Hey everyone (but specifically John Wise),

I just pulled to the newest version of yt, and I got significantly different
behavior from some old scripts of mine which use yt than I did prior to the
pull.  I bisected the changesets to the one making the big difference for
me, and it was your commit: 71c2bfaa3b5f from late January.

Specifically, I'm doing some off axis projections which use the volume
rendering interface and ghost zones.  I homogenize my volume, then take a
snapshot of the interior.  When I do this with my old code, it takes about
20 seconds to partition and homogenize the volume, but now it takes over 10
minutes to partition the volume (I actually kill it at 10 minutes), and
it uses so much memory that all of my other programs grind to a halt on a
relatively big memory machine.

I was wondering if you (or anyone else on the list) encountered any problems
in volume rendering with ghost zones since this changeset (i.e. the last two
months), or if you can think of any obvious reasons why there would be such
a slow down?  I know you're out of town right now, but I figured I'd send
this to the list anyway to see if anyone else had experienced slowdowns.
Thanks for the help!

Cameron