** Description changed: - This (very nice!) default theme use, for many widgets, the "inset" text - rendering mode from murrina engine. While beautiful, this "engraved" - text rendering effect cause a very high CPU load when a moving window - overlaps another one, static window. This results in the overlapped - window issuing many expose events that can not be served in time, so a - grey trail is visible behind the moving window. + SRU explanation: + [Impact]: This bug impact performance on default installaion of Lubuntu, on some configurations + [Development Fix]: This bug was fixed in 0.19 version of lubuntu-artwork, by disabling inset on theme configuration + [Stable Fix]: Same fix than the development fix can by apply (see http://launchpadlibrarian.net/83896618/lubuntu-artwork_0.18_0.19.diff.gz) + [Test Case] From the original report : + a) open a window with some text (eg: obconf -> appearance) + b) open a terminal window and run top + c) open another window and keep moving it over the previous one + d) read, from top, the cpu usage: it will at be near 100% for one core + [Regression Potential] : Minimal, eventually some graphical difference in some cases, but the tests doesn't show any visual differences + + Original report : + This (very nice!) default theme use, for many widgets, the "inset" text rendering mode from murrina engine. While beautiful, this "engraved" text rendering effect cause a very high CPU load when a moving window overlaps another one, static window. This results in the overlapped window issuing many expose events that can not be served in time, so a grey trail is visible behind the moving window. Steps to reproduce this: a) open a window with some text (eg: obconf -> appearance) b) open a terminal window and run top c) open another window and keep moving it over the previous one d) read, from top, the cpu usage: it will at be near 100% for one core (my machine has an i5-520 CPU @ 2.4 GHz) Possibile solutions: a) enable X-based when-mapped backing store b) use compiz (or other gl-based wm) as window manager c) simply disable "inset" text rendering or change default theme Solutions a) and b) have their problems and controindications (especially for a resource-contrained distribution as Lubuntu). Solution c) is the most obvious: simply disable inset text rendering and CPU usage decrease significantly. Thanks ProblemType: Bug DistroRelease: Ubuntu 11.10 Package: lubuntu-artwork 0.18 ProcVersionSignature: Ubuntu 3.0.0-12.20-generic 3.0.4 Uname: Linux 3.0.0-12-generic x86_64 ApportVersion: 1.23-0ubuntu3 Architecture: amd64 Date: Thu Oct 20 18:31:43 2011 InstallationMedia: Lubuntu 11.10 "Oneiric Ocelot" - Release amd64 (20111012) PackageArchitecture: all ProcEnviron: - LANG=it_IT.UTF-8 - SHELL=/bin/bash + LANG=it_IT.UTF-8 + SHELL=/bin/bash SourcePackage: lubuntu-artwork UpgradeStatus: No upgrade log present (probably fresh install)
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