Hi Steve, I found out that the tracer got stuck on ppc32 platforms because some early functions call _mcount before mcount_enabled is initialized at all. I made a patch, which marks these functions as notrace to solve this problem. With this patch I can successfully boot up our mpc5200b platform and make latency trace. (tested with -b switch in cyclictest). Please comment. I made my patch against the -rt2 tree since the dummy call early_printk() in -rt3 conflicts with our implementation of a functional early_printk(). It should also work with -rt3 though. cheers Luotao Fu -- Dipl.-Ing. Luotao Fu | Phone: +49-5121-206917-3 Pengutronix - Linux Solutions for Science and Industry Entwicklungszentrum Nord http://www.pengutronix.de