https://bugs.documentfoundation.org/show_bug.cgi?id=152911
--- Comment #21 from M. Knepper <[email protected]> --- (In reply to Jeff Fortin Tam from comment #20) > Just some wild "what if?..." guessing based on what M. Knepper's video in > comment #19 about the high CPU usage in htop while scrolling a wall of > text... > > * Let's say you grab a 4K screen, but do not set the display scaling to 2x > HiDPI, just use it at its "native panel resolution", and size the > libreoffice window at various sizes (ex: a quarter of the screen, half of > the screen, full size of the screen, etc., do you still see this happening, > and do you see differences in the percentage of CPU used in each case? > > * Could Cairo be the bottleneck? I see we're all running the Cairo version > of LibreOffice, not Skia: as far as I know, Cairo is all CPU rendering, > whereas Skia renders everything (I think?) on the GPU and should be an order > of magnitude faster as a result. Maybe you could try running the Skia > version (using the trick in > https://github.com/flathub/org.libreoffice.LibreOffice/issues/ > 213#issuecomment-1450176774 for the flathub flatpak version) and see if the > problem vanishes with it? The Fedora video was recorded with a scaling of 100%, forgot to mention that. So the video I recorded in question is 1x scaling. My guess is it will be much, much worse if I set it to 200%. Additional Note: Walls of text do not seem to be an issue in other word processors. For instance, I write novels (80k words plus, 100s of pages), and it's fine in MS Word. I can open the same document (either .docx or .odt format) and the same problem occurs - LibreOffice will use 80%~ or so of the CPU. I'll try forcing Skia if Fedora/24.x will let me. But yeah, the video I recorded was at 100% scaling or 1x, not 200% or any other fraction (though I'm able to reproduce this problem with fractional scaling on Linux Mint MATE and Cinnamon). -- You are receiving this mail because: You are the assignee for the bug.
