Quite often when the system is very stressed (high CPU usage, filled RAM, swap/hdd in use; very slow response), the screen goes blank after doing something that reqiures a redraw (moving a window, closing a window, scrolling, changing a tab, etc.). Kernel Radeon DRM w/modesetting enabled, R300.
Created attachment 256695 [details] kernel log The last messages goes on and on.
This is a known regression being tracked upstream. We'll watch the upstream bug and backport any fix which becomes available.