Hi, Marco - I'll be distributing the code I've been working on - I just want to do a bit more testing. I think I'll be using a SourceForge repository.
The changes I've been making affect the standard shared-memory model of OpenDX. The work I did a long time ago on an MPI-based distributed-memory version was built on top of the shared-memory model; whether that is multi-process or multi-thread should be immaterial. However, I'm not sure I'm going to try to resurrect that stuff; it was only a prototype and never really became real. I don't believe the system has been flushing the cache at all, in the past. Thats why it would run until it ran out of memory, take a few half-hearted efforts at scavenging, and then stop. At which point you could explicitly flush the cache, and it'd proceed along just fine - until it ran out of memory again. I have a test progeam that steps up and back through 1000 isovalues; the old code would not run very long before stopping with an out-of-memory error. With the fix in, even in very constrained memory it keeps running a *long* time. Greg Gregory D. Abram Texas Advanced Computing Center JJ Pickle Research Campus - ROC 1.101 Bldg 196 10100 Burnet Road Austin, Texas 78758-4497 g...@tacc.utexas.edu (512) 471-8196 ________________________________________ From: Marco Morandini [morand...@aero.polimi.it] Sent: Monday, October 26, 2009 5:49 AM To: Greg Abram Cc: opendx2-users@lists.berlios.de Subject: Re: [OpenDX2-users] OpenDX development Greg Abram wrote: > Hi - > > Anyone out there? I'm wondering if anyone is interested in some > work I've been doing on OpenDX - I've replaced the multi-process > model with a multi-threaded one, enabling a much (much!) simplified > memory manager. This enables me to remove the limit on memory size > (though I bet you'd better not allocate any individual object larger > than 2GB). It'll just consume virtual-memory page-space until it > hits an arbitrary limit (suggestions?) when it will begin to flush > the cache. Fragmentation is also much less of a problem. > It would be great if you could post the patches, so that they remain archived somewhere, waiting for someone to re-vitalize the project. Do the multi-thread model rules out the possibility to use mpi? I'm also very interested in the cache bug you mentioned in the forum. Thanks, Marco _______________________________________________ OpenDX2-users mailing list OpenDX2-users@lists.berlios.de https://lists.berlios.de/mailman/listinfo/opendx2-users
