There are following performance regressions in build 8.0-controls-scrum-849:
 Controls.ListView-Keyboard: -27% (-58.98 fps)
 Controls.TreeView-Keyboard: -38% (-44.28 fps)


The regressions are caused by fix for "RT-25059: ListView scroll bar thumb resizes wildly" which changed
diff -r dbcbfaf3abb4 -r d61aca2e2f9b modules/controls/src/main/java/com/sun/javafx/scene/control/skin/VirtualFlow.java
--- a/modules/controls/src/main/java/com/sun/javafx/scene/control/skin/VirtualFlow.java Wed Sep 25 10:01:43 2013 +1200
+++ b/modules/controls/src/main/java/com/sun/javafx/scene/control/skin/VirtualFlow.java Wed Sep 25 12:05:27 2013 +1200
@@ -1467,7 +1467,9 @@
                 // only a single row and it is bigger than the viewport
                 lengthBar.setVisibleAmount(flowLength / sumCellLength);
             } else {
- lengthBar.setVisibleAmount(numCellsVisibleOnScreen / (float) cellCount);
+ // Changed the calculation here due to RT-25059. This new approach
+ // ensures the thumb does not resize unexpectedly.
+ lengthBar.setVisibleAmount(cellCount / viewportLength);
             }


As result lengthBar.setVisibleAmount is now called with 20.0803 instead of 0.0021 in case of running
Controls.ListView-Keyboard benchmark. As result the time spent in com.sun.javafx.scene.control.skin.VirtualFlow.show
has been increased which dropped the performance. Here are JPA data for 848 and 849 builds:

848
===
10.398 com.sun.javafx.scene.control.skin.ListViewSkin.onSelectPreviousCell()
2.348 com.sun.javafx.scene.control.skin.ListViewSkin.onSelectNextCell()
--------------------------------
0.036 com.sun.javafx.scene.control.skin.VirtualFlow.show(int)
--------------------------------
11.779 com.sun.javafx.scene.control.skin.VirtualFlow.show(javafx.scene.control.IndexedCell)
0.387 com.sun.javafx.scene.control.skin.VirtualFlow.resizeCellSize(javafx.scene.control.IndexedCell)
0.287 com.sun.javafx.scene.control.skin.VirtualFlow.setCellIndex(javafx.scene.control.IndexedCell, int)
0.165 com.sun.javafx.scene.control.skin.VirtualFlow.getCellBreadth(javafx.scene.control.Cell)
0.025 com.sun.javafx.scene.control.skin.VirtualFlow.getVisibleCell(int)
0.025 javafx.scene.Node.setVisible(boolean)
0.015 com.sun.javafx.scene.control.skin.VirtualFlow.positionCell(javafx.scene.control.IndexedCell, double)
0.013 com.sun.javafx.scene.control.skin.VirtualFlow.adjustPositionToIndex(int)
0.006 com.sun.javafx.scene.control.skin.VirtualFlow.getAvailableCell(int)
0.005 com.sun.javafx.scene.control.skin.VirtualFlow.getCellLength(javafx.scene.control.IndexedCell)
0.002 com.sun.javafx.scene.control.skin.VirtualFlow.requestLayout()
0.001 java.lang.Math.max(double, double)
0.001 com.sun.javafx.scene.control.skin.VirtualFlow$ArrayLinkedList.addLast(java.lang.Object)

848
===
9.280 com.sun.javafx.scene.control.skin.ListViewSkin.onSelectNextCell()
7.064 com.sun.javafx.scene.control.skin.ListViewSkin.onSelectPreviousCell()
--------------------------------
0.073 com.sun.javafx.scene.control.skin.VirtualFlow.show(int)
--------------------------------
10.819 com.sun.javafx.scene.control.skin.VirtualFlow.show(javafx.scene.control.IndexedCell)
2.390 com.sun.javafx.scene.control.skin.VirtualFlow.resizeCellSize(javafx.scene.control.IndexedCell)
1.744 com.sun.javafx.scene.control.skin.VirtualFlow.setCellIndex(javafx.scene.control.IndexedCell, int)
1.089 com.sun.javafx.scene.control.skin.VirtualFlow.getCellBreadth(javafx.scene.control.Cell)
0.089 com.sun.javafx.scene.control.skin.VirtualFlow.positionCell(javafx.scene.control.IndexedCell, double)
0.053 com.sun.javafx.scene.control.skin.VirtualFlow.getAvailableCell(int)
0.050 com.sun.javafx.scene.control.skin.VirtualFlow.getVisibleCell(int)
0.012 com.sun.javafx.scene.control.skin.VirtualFlow$ArrayLinkedList.addLast(java.lang.Object)
0.012 javafx.scene.Node.setVisible(boolean)
0.006 com.sun.javafx.scene.control.skin.VirtualFlow.getCellLength(javafx.scene.control.IndexedCell)
0.004 com.sun.javafx.scene.control.skin.VirtualFlow.getCellPosition(javafx.scene.control.IndexedCell)
0.001 com.sun.javafx.scene.control.skin.VirtualFlow.setMaxPrefBreadth(double)


Steps to run Controls.ListView-Keyboard:
> cd JFX_WS/tests/performance/Controls/
 > ant
 > java-Djavafx.animation.fullspeed=true
       -cp "JFX_HOME/rt/lib/jfxrt.jar;./dist/Controls.jar;../FXBenchmark/dist/FXBenchmark.jar;../../../import/benchmarks-2.1.1/benchmarks-2.1.1.jar"
       jrockit.bm.Main controls.bm.ListViewBenchmark -i 1 -wt 0 -tr 60 -mode keyboard -keysPerInjection 100 -cells 10000