Hey Chris, Thanks heaps. I'll have a look and get back with any findings (may take a day or two before I get to it).
cheers, Juha 2014-11-27 3:51 GMT+02:00 Chris Adams <[email protected]>: > Hi Juha, > > For some more light on this issue, are you able to run the > qtdeclarative/tests/benchmarks/qml/librarymetrics_performance benchmark on > both 5.1 and 5.3 (you may have to backport to 5.1 as IIRC I made some > changes to the way the components were instantiated for 5.2 before the > benchmark was integrated, but I may be wrong about that. It was originally > written prior to Qt5.0 release so with some minor changes it will definitely > work against 5.1). > > The benchmarks are quite granular, and should allow you to see precisely > which part of the component instantiation is significantly slower. > > Kind regards, > Chris Adams. > > > www.qinetic.com.au - Qt And QML User Experience Specialists > > On Wed, Nov 26, 2014 at 6:08 PM, Juha Vuolle <[email protected]> wrote: >> >> Hello, >> >> apologies for cross-posting. I find this such a fundamental issue that I >> feel >> at least having the best possible understanding of it worth it (if any >> exists, which is also >> a valuable information in itself). I am happy to help if there is >> anything I could check. >> >> thanks, >> Juha >> >> --- >> >> Hello, >> >> I’m having trouble going from Qt 5.1 to 5.3 / 5.4 because of a >> slowdown in QML (15..35% slower). >> This primarily relates to component instantiation and seems quite >> consistent across the platforms and >> QPAs I’ve used recently. >> >> If you have any insights, thoughts or something I could check I would >> highly appreciate them. >> >> I’ve tested on dual & quadcore imx6 (both EGLFS and XCB) embedded >> platform as well as >> few desktop Fedoras. I’ve tested with 5.1.1, 5.3.1 and the latest >> 5.4.0. The slowdown varies >> but is fairly consistently between 15..35 %. Instantiation CPU loads >> do not seem to be particularly high (< 70%). >> >> Running QML profiler seems to make results less predictable. So I made >> a very simple application startup timer >> that checks main() -> QQuickWindow::beforeSynchronizing() -> >> beforeRendering() -> afterRendering() -> frameSwapped(). >> Please find my "highly scientific" measurements below. I slowed down >> the CPU to make things more clear on the desktop I’m writing >> this email from. This behaviour is not specific to only application >> startup but later runtime instantiations seem also slower. >> >> I am grateful for any thoughts or things I could check. >> >> Thanks, >> Juha >> >> Qt 5.1.1 low CPU qtquickcontrols gallery example startup: >> 1. onBeforeSynchronizing() for the FIRST time, time it took from main(): >> 950 >> 2. onBeforeRendering() time it took from beforeSynchronizing: 3 >> 3. onAfterRendering() time it took from beforeRendering: 1572 >> 4. onFrameSwapped() time it took from afterRendering: 5 >> = 2530 ms for first frame swapped. >> >> Qt 5.3.1 low CPU qtquickcontrols gallery example startup: >> 1. onBeforeSynchronizing() for the FIRST time, time it took from main(): >> 1843 >> 2. onBeforeRendering() time it took from beforeSynchronizing: 364 >> 3. onAfterRendering() time it took from beforeRendering: 1039 >> 4. onFrameSwapped() time it took from afterRendering: 83 >> = 3329 ms for first frame swapped. >> >> Qt 5.1.1 low CPU my application startup: >> 1. onBeforeSynchronizing() for the FIRST time, time it took from main(): >> 809 >> 2. onBeforeRendering() time it took from beforeSynchronizing: 3 >> 3. onAfterRendering() time it took from beforeRendering: 1373 >> 4. onFrameSwapped() time it took from afterRendering: 88 >> = 2273 ms for the first frame swapped >> >> Qt 5.3.1 low CPU my application startup: >> 1. onBeforeSynchronizing() for the FIRST time, time it took from main(): >> 1341 >> 2. onBeforeRendering() time it took from beforeSynchronizing: 4 >> 3. onAfterRendering() time it took from beforeRendering: 2184 >> 4. onFrameSwapped() time it took from afterRendering: 10 >> = 3539 ms for the first frame swapped >> _______________________________________________ >> Development mailing list >> [email protected] >> http://lists.qt-project.org/mailman/listinfo/development > > _______________________________________________ Development mailing list [email protected] http://lists.qt-project.org/mailman/listinfo/development
