Hi Yordan, While looking at my data, I found that the red empty boxes to represent preemption for task plots is still unreliable. Down load this: http://rostedt.org/private/trace-views.tar.bz2 Then in the /tmp directory: /tmp$ tar xvf trace-views.tar.bz2 Start up KernelShark, and import view1.json. Notice the red preemption box and what tasks they are for. Then load view2.json and do the same, the view3.json, and that as well. You'll notice that each one gives different preemption boxes in the same location. -- Steve P.S. The session files really help with passing you debugging info like this :-)