Terje, did yo test the ToT(1211) kernel? Could you tell me which ftrace configs you enabled? And what is your kernel command line? Mark On 12/12/2012 08:26 PM, Terje Bergström wrote: > On 12.12.2012 13:27, Mark Zhang wrote: >> Hi all, >> >> Has anyone tried to use ftrace to debug upstream kernel? I tried today >> but the result is, the serial console hung after ftrace enabled(kernel >> is alive because the Magic SysRq works). >> >> My steps are: >> - Enable CONFIG_FUNCTION_TRACER in kernel config >> - Enter command: echo 0 > /sys/kernel/debug/tracing/tracing_on;echo >> function > /sys/kernel/debug/tracing/current_tracer;echo 1 > >> /proc/sys/kernel/ftrace_dump_on_oops >> - Then sometimes the serial console hangs right after you entered the >> command above, or hangs when you try to "cat /sys/kernel/debug/trace" >> >> I dumped some backtraces(check below, by invoking a system crash >> manually) and hope it helps: > > I'm using ftrace to debug host1x driver + tegradrm, running on Tegra2 > ventana. I just rebased them on linux-next, and I use just the events, > not function tracing. > > echo 1 >/sys/kernel/debug/tracing/events/host1x/enable > ~/drm/tests/tegra/2d/tegra_2d_tests > cat /sys/kernel/debug/tracing/trace > > I get host1x events as expected. > > Also function tracing works. > > Terje > -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
