On my Debian 10 system, Gimp's memory usage builds up as I open/close files and never goes down until I quit Gimp, leading it to fill the memory and use the swap even though I have 64GB of RAM and each xcf file is less than 1GB (and I only open one at a time).
Is there a setting I can change to make Gimp free memory when an image gets closed?
No setting for this. This shouldn't happen. And it doesn't happen on my 2.10.14 or 2.10.20 versions on Ubuntu, at least on a test image (20000x20000, two layers filled with plasma). Could be a left over debug option or a bug in some system library. What build are your using, the regular .deb from Debian, the flatpak, something self-compiled?
Ok, thanks. To give more context, the systems (actually 2 of them, probably even 3) on which this happens have been dist-upgraded without getting a fresh install since I think Debian 7 (not my doing in case you're wondering), while another one I've recently fresh-installed doesn't have this problem. So I guess it would be better that I try harder to convince the system administrator of the importance of doing a fresh install from time to time rather than spend time digging to the root cause of this -one of several- issues and finding a solution provided there is one other than a fresh install. In other words, nevermind!