This patch uses threading to flush selection from verts to edges and from edges to faces. The solution is lockless and should scale well on modern CPU architectures. Master:{F10185359} Patch:{F10185361} End user performance went from 3.9 to 4.6 FPS (Stanford Dragon) but that was measured on a Intel Core i7-6700 CPU and AMD RX480 Gpu. The more cores the better improvements you get. Reviewed By: mano-wii Differential Revision: https://developer.blender.org/D11644