I'm currently running an animation that uses ~12GB of memory.
Before Pov renders a frame it parses the data using a hunk of memory, 
then renders it and disposes of everything in memory, ready to start over.
Here's my confusion, if a frame completes shouldn't mem use drop to what 
the system uses and not stay at 13+GB?

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Am 23.12.2013 09:12, schrieb Ger Remmers:
> I'm currently running an animation that uses ~12GB of memory.
> Before Pov renders a frame it parses the data using a hunk of memory,
> then renders it and disposes of everything in memory, ready to start over.
> Here's my confusion, if a frame completes shouldn't mem use drop to what
> the system uses and not stay at 13+GB?

Memory management in the OS is a comparatively time-consuming process, 
and modern computer programs tend to allocate, de-allocate and 
re-allocate quite a lot. Therefore, applications usually have their own 
layer of memory management (as part of the runtime library) that tries 
to minimize OS involvement; most notably, memory currently not in use is 
kept around for a few moments, just in case the program needs another 
chunk of memory soon.

It might well be that the parsing time is short enough that the runtime 
library keeps all the allocated memory around.

If that's not the case, the OS itself may also be lazy in reclaiming 
released memory, for the very same reason. The OS might even choose to 
keep the memory ready for the application to use, and not actually 
reclaim it until the application terminates or the system runs low on 
virtual memory.

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