Resizing issue with Compositing

[bridgman]

The artifacts were only observed on Intel IGP parts AFAIK (that's why the optimization was removed from the X server, and why it was felt to be safe to use the re-patched server for non-Intel hardware) - are the artifacts (essentially a window full of garbage, which might include old screen data) now being reported on other hardware as well ?

[neyz]

I have no idea but it's more than frustrating to not be able to use KDE4's desktop to it's full potential because of this problem. And more than that, if the problem is fixed it will probably be in 1.6 but then fglrx would need to support 1.6 which isn't the case yet if i'm not mistaken ^^

Cheers !

[BlackStar]

The artifacts were only observed on Intel IGP parts AFAIK (that's why the optimization was removed from the X server, and why it was felt to be safe to use the re-patched server for non-Intel hardware) - are the artifacts (essentially a window full of garbage, which might include old screen data) now being reported on other hardware as well ?

Nope, the garbage is (and has always been) visible with fglrx. It appears on all hardware I've tested (R300, R500 and R700), but it is completely innocuous: the effect is similar to a scrambled pixmap (imagine trying to decode a pixmap using a wrong line stride) and it's visible for just a few hundred milliseconds. This might be different on Intel hardware, but it's absolutely impossible to glean any recognizable information from the scrambled image on fglrx.

Of course, the ideal would be for the driver to work correctly with upstream Xorg (no garbage at all). Using the no-backfill patch is a workaround for poor driver performance in this specific code path.

On another note, slow gnibbles resizes have absolutely nothing to do with this patch. This is a matter of slow updates upon expose events, probably due to the specific game logic or the amount of graphics on display.

[bridgman]

Yeah, it's not clear how this is going to shake out. Most of the discussion when this issue first tipped up (KDE4 showing garbage for a long time on certain hardware) seemed to focus on the difference between how Gnome/Compiz and KDE/KWin handled things. The early conclusion seemed to be that Gnome did things right, KDE did not, but even so the 107-fedora-dont-backfill optimization had to be pulled "for security reasons".

The core issue still seems to remain unresolved, however. The conclusion seemed to be that the X protocol is unclear how this situation should be handled, so different groups came up with different ways to work around the problem. Each group declared the others solution a "hack", one set of hacks replaced the other, and here we are ;(

I haven't seen any signs that KDE4.x is going to change to match what was working with Gnome/Compiz, and discussion on the core issue seems to have ground to a halt, so we may end up having to "replace support for the old hack with support for the new hack" in order to get performance back.

XDC is coming up soon, so it might be possible to get the underlying issue discussed and resolved for good. I'll ask around and see what the chances are.

[tball]

Why is everyone saying its an fglrx issue?
If you patch a xserver with the dont_backfill_bg patch, then you will have a fast responding desktop with composite.

I have made a package for Arch named xorg-server-catalyst-maximize-fix in aur. It works just fine.

Try see if you can find a similar patched xorg-server for suse.

http://aur.archlinux.org/packages.php?ID=26687

[adamk]

Why is everyone saying its an fglrx issue?

Maybe because the open source drivers can do resizing flawlessly?

Adam