Merging layers seems to enlarge memory usage for current document. I feel that it's because krita have to storage data for undo actions, maybe?

Just curious if it's not a bug.

After merging 15+ layers :


After re-opening the file :

Having the image layer data required to perform Undo actions does require memory of course and that may explain it. What was the memory usage before you merged the layers?

ahabgreybeard wrote:Having the image layer data required to perform Undo actions does require memory of course and that may explain it. What was the memory usage before you merged the layers?

The same as the one after re-opening the file. (Slightly less then that, actually.)

Oh, I was wrong. It appeared like this :


And deleting layers instead of merging them doesn't seem to affect the memory usage in the same way. I thought it's kinda weird if it's for undo actions.

That is even more of a puzzle if you consider the need to be able to undo merges and deletions. However, if you use the task manager to see how much RAM krita is using, that amount doesn't go down until you close the image and then make or open a new (small) image. That may be related to the need to undo actions (or it may be something else entirely.)

I notice the coloured 'slider' bars on the image size/memory indicator, are you using a 4.2.0 pre-alpha? I don't know the significance of those bars and they seem to show caution/warning by being blue, yellow or red. They happen when I have plenty of RAM left so I can't figure out the logic of their appearing but their length seems to correrspond to the amount of RAM used.

Can anybody explain what they are, what they do and how they behave?

yes, it's the "Improve display of memory usage" in 4.2, see there
https://krita.org/en/krita-4-2-release-notes/

Yes, they were implemented to give people a better understanding of how much ram an image can take up, as a lot of Krita users are super inexperienced with computers, but still want to make a 1hour 60fps 4k animation in Krita, which is rather impossible if you don't know what ram is or have a conception of how much Krita is using.

I guess I could ask Dmitry if he knows what is up here, memory wise...

Thank you, to both of you, for the reference and the explanation. (I should read release notes more carefully and in more detail.)

Blue seems to mean 'no problem', yellow seems to mean 'be careful' and red obviously means 'you're nearly in trouble'. The two different shades and their extent look like the proportions of two different types of memory usage within krita as a fraction of the total memory allocation.