[...] = "basic" render
$ QSG_INFO=1 mediawriter Debug: QSG: basic render loop ((null):0, (null)) Debug: texture atlas dimensions: 1024x512 ((null):0, (null)) Debug: R/G/B/A Buffers: 8 8 8 0 ((null):0, (null)) Debug: Depth Buffer: 24 ((null):0, (null)) Debug: Stencil Buffer: 8 ((null):0, (null)) Debug: Samples: -1 ((null):0, (null)) Debug: GL_VENDOR: nouveau ((null):0, (null)) Debug: GL_RENDERER: Gallium 0.4 on NV98 ((null):0, (null)) Debug: GL_VERSION: 3.0 Mesa 13.0.0-rc2 ((null):0, (null)) Debug: GL_EXTENSIONS: ... Debug: Max Texture Size: 8192 ((null):0, (null)) Debug: Debug context: false ((null):0, (null)) ... $ ps -C mediawriter -o cmd,%cpu CMD %CPU mediawriter 30.1 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ = "windows" render $ QSG_INFO=1 QSG_RENDER_LOOP=windows mediawriter Debug: windows render loop ((null):0, (null)) Debug: Using sg animation driver ((null):0, (null)) Debug: Animation Driver: using vsync: 16.67 ms ((null):0, (null)) Debug: texture atlas dimensions: 1024x512 ((null):0, (null)) Debug: R/G/B/A Buffers: 8 8 8 0 ((null):0, (null)) Debug: Depth Buffer: 24 ((null):0, (null)) Debug: Stencil Buffer: 8 ((null):0, (null)) Debug: Samples: -1 ((null):0, (null)) Debug: GL_VENDOR: nouveau ((null):0, (null)) Debug: GL_RENDERER: Gallium 0.4 on NV98 ((null):0, (null)) Debug: GL_VERSION: 3.0 Mesa 13.0.0-rc2 ((null):0, (null)) Debug: GL_EXTENSIONS: ... Debug: Max Texture Size: 8192 ((null):0, (null)) Debug: Debug context: false ((null):0, (null)) ... $ ps -C mediawriter -o cmd,%cpu CMD %CPU mediawriter 41.2 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ = "threaded" render $ QSG_INFO=1 QSG_RENDER_LOOP=threaded mediawriter Debug: threaded render loop ((null):0, (null)) Debug: Using sg animation driver ((null):0, (null)) Debug: Animation Driver: using vsync: 16.67 ms ((null):0, (null)) Debug: Animation Driver: using vsync: 16.67 ms ((null):0, (null)) Debug: texture atlas dimensions: 1024x512 ((null):0, (null)) Debug: R/G/B/A Buffers: 8 8 8 0 ((null):0, (null)) Debug: Depth Buffer: 24 ((null):0, (null)) Debug: Stencil Buffer: 8 ((null):0, (null)) Debug: Samples: -1 ((null):0, (null)) Debug: GL_VENDOR: nouveau ((null):0, (null)) Debug: GL_RENDERER: Gallium 0.4 on NV98 ((null):0, (null)) Debug: GL_VERSION: 3.0 Mesa 13.0.0-rc2 ((null):0, (null)) Debug: GL_EXTENSIONS: ... Debug: Max Texture Size: 8192 ((null):0, (null)) Debug: Debug context: false ((null):0, (null)) ... $ ps -C mediawriter -o cmd,%cpu CMD %CPU mediawriter 18.3 ... Debug: animation driver switched to timer mode ((null):0, (null)) Debug: animation driver switched to vsync mode ((null):0, (null)) Debug: Animation Driver: using vsync: 16.67 ms ((null):0, (null)) Debug: texture atlas dimensions: 1024x512 ((null):0, (null)) Segmentation fault (core dumped) QSGRenderThread[8636]: segfault at 8 ip 00007f9138a4320f sp 00007f911cd908f0 error 4 in libdrm_nouveau.so.2.0.0[7f9138a3f000+7000] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ = About $ rpm -q mediawriter mediawriter-4.0.3-2.fc26.x86_64 built without "threaded" render: $ grep sed mediawriter.spec -A2 sed -i /threaded/s/^/\\/\\// app/main.cpp %build $ rpm -q qt5-qtbase-devel qt5-qtdeclarative-devel qt5-qtbase-devel-5.7.0-9.fc26.x86_64 qt5-qtdeclarative-devel-5.7.0-2.fc25.x86_64 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ = Conclusion From the nouveau perspective, "threaded" render is "out of scope". Ref. Force threaded run loop for QML - Fixes high CPU load https://github.com/MartinBriza/MediaWriter/commit/63492f4 Qt Quick Scene Graph - Scene Graph and Rendering https://doc.qt.io/qt-5/qtquick-visualcanvas-scenegraph.html#scene-graph-and-rendering _______________________________________________ Nouveau mailing list Nouveau@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/nouveau