Thanks, Martin, for the detailed advice. I tried pidstat and feel that it tells me no more than the fact that the abnormal resource is taken by one of the 4 subprocesses of the program I am running with Wine. I know the problem comes from there, but I still don't know how is happening inside and how to find a fix. Played around with the program further and found something interesting. The abnormal resource usage is actually not due to a switch of focus between graphics and GUI. It is due to mouse movement in the graphics area under certain circumstances. The circumstances include having stock price moving average lines drawn on the chart, which was the default feature. Turning off the moving average lines or switch to certain other indicators can make the problem go away. I can not image what is going on. Why mouse moving with MA drawn sucks so much resource? Again this is not detected at all under Windows. Any good imagination please?
