Hi,
I don't quite remember where exactly this was implemented. It was not a shared buffer, though. IIRC the buffer allocation code in one of the libs rounded the size towards multiples of 64. I remember thinking that it was probably done for tiled rendering.
Happens when running gnome in wayland mode, so whatever the display server is in that case (mutter?) or one of the libraries it uses.
Yeah, but you don't do rendering on dumb buffers. Like ever. So this smells like a userspace bug.
If it's for shared buffers then I think that sounds more reasonable.
Well, wayland can use dma-bufs for buffer sharing between wayland server and wayland client. Dunno whenever it also does that for the software rendering case, and I have absolutely no idea how the buffer allocation code paths look like. But possibly it isn't known at buffer allocation time whenever a given buffer will be touched by a gpu at some point in the future?
take care, Gerd