From kde-bugs-dist Mon May 25 14:36:33 2015 From: Mark Date: Mon, 25 May 2015 14:36:33 +0000 To: kde-bugs-dist Subject: [kwin] [Bug 348206] New: KWin CPU usage rises when mplayer is playing a video Message-Id: X-MARC-Message: https://marc.info/?l=kde-bugs-dist&m=143256460501231 https://bugs.kde.org/show_bug.cgi?id=348206 Bug ID: 348206 Summary: KWin CPU usage rises when mplayer is playing a video Product: kwin Version: unspecified Platform: Compiled Sources OS: Linux Status: UNCONFIRMED Severity: normal Priority: NOR Component: core Assignee: kwin-bugs-null@kde.org Reporter: markg85@gmail.com Hi, I was playing a video in mplayer with the system monitor up. The case for that was observing mplayer cpu usage to determine if hardware accelerated decoding was working (it was). While doing that i noticed kwin going up in CPU usage. Only up to 1 percent so it's still nothing to worry about, but it does "point" to something in the kwin code that is running quite heavily while.. watching a video with mplayer.. I don't see a relation there so kwin might be doing something it doesn't need to do. So i ran kwin through callgrind (via valgrind) to figure out what's going on here. I didn't have debug symbols for the full frameworks/plasma/qt stack, just for kwin, so my findings might not expose the actual issue, but they will point in the direction of it. It looks like QObject::property is being called very often when opening an mplayer window. This property is being called (in a cycle) in kwineffects.cpp. The top callers of QObject::property are: - KWin::EffectWindow::pos - KWin::EffectWindow::isDesktop - KWin::EffectWindow::hasAlpha - KWin::EffectWindow::opacity - KWin::EffectWindow::isDeleted - KWin::EffectWindow::contentsRect What is going on here? Why are these methods (among a lot of others, but they call QObject::property less) being called in a cycle for mplayer, but not for - for instance - dolphin? One thing that's very important to notice when you decide to debug and fix this. The kwin cpu usage only goes up to 1% (and stays there) when _playing_ a video. Just having the mplayer window with a video in pause will not make kwin hang on 1%. If you need more info, feel free to ask. Reproducible: Always -- You are receiving this mail because: You are watching all bug changes.