[mkgmap-dev] Memory limits for mkgmap and splitter

Fri Aug 7 09:36:14 BST 2009

Thanks for the info. Sounds like you've found about the same limit I have 
with --max-nodes and -Xmx4000m. This weekend I'm going to add a --max-areas 
parameter. Setting this to a number < 255 should allow for higher a --max-nodes 
value with the same heap size. In your case with 367 areas, setting --max-areas=184 
should allow for a higher max-nodes setting without any extra passes required.

> Tested this latest version on my American extract with -Xmx4000m:
> 
> With 1.2 million nodes the Java VM crashed due to lack of memory.
> Using
> 1 million nodes the split succeeded with 367 areas in 3:20 hours.
> Some
> swapping was noticed (bad for speed).
> Although I'd rather use the 1.2 million setting, as that is a nice
> balance between the number of failed map builds and map size
> worldwide, using 1 million now enables me to do all the work myself
> instead of relying on others. Great, thanks a million!
> 
> Next up: splitting the whole world on my laptop and process the output
> with mkgmap. See which areas need fixing manually...