[split] GIMP crashes randomly

[Ofnuts]

So yes, tile cache went full during the operation, and Gimp started to use its swap, which is likely to slow it down significantly. Two things that surprise me:

• Your cache is only 3GB on a 8GB machine running Linux
  
• All your cores going flat out together. When I did my tests, only one CPU maxed (despite several settings to make it possible to use several) so the path rendering is likely single threaded. So what were the other cores doing? Is your filesystem encrypted?
  

Something that you can keep an eye on is Image > Properties. This tells you how much memory is taken by your image. Just loading the image and you are at 1.5GB, then undo steps are 500MB apiece. In the Undo history dialog you can clear the undo history to reclaim all that memory.