On Thu, 2013-06-13 at 21:04 +1000, Michael Ellerman wrote: > Although that should be sufficient to fix the bug, we also mark the > runlatch routines as notrace. They are called very early in the > exception entry and we are asking for trouble tracing them. They are > also fairly uninteresting and tracing them just adds unnecessary > overhead.
Note, I usually lean towards tracing everything that can be traced, and only adding notrace to things that will actually cause a crash. If you don't like them to be traced, you can always do: echo '*__ppc64_runlatch_*' > /sys/kernel/debug/tracing/set_ftrace_notrace and that will keep them from being traced. You can also add it to the kernel command line with: ftrace_notrace=*__ppc64_runlatch_* which will also disable them on boot up. Also trace-cmd has: trace-cmd record -p function_graph -n '*__ppc64_runlatch_*' that will do the same thing. Hmm, I should add a way to disable things that are usually considered noise. Perhaps add something like: FTRACE_DEFAULT_OFF(__ppc64_runlatch_on); That adds the function to a different section that places it into another file that keeps it from being traced, but can be enabled when you want it to. -- Steve _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
