Messages in this thread | | | Date | Sun, 06 Jul 2008 11:34:38 +0200 | From | Wolfgang Grandegger <> | Subject | Re: 2.6.24-rc8-rt1: Strange latencies on mpc5200 powerpc - RCU issue? |
| |
Steven Rostedt wrote: > On Wed, 2 Jul 2008, Wolfgang Grandegger wrote: > >> Steven Rostedt wrote: >>> On Tue, 1 Jul 2008, Wolfgang Grandegger wrote: >>>> I continue this thread because it's still not understood why enabling >>>> CONFIG_RCU_TRACE is necessary to get reasonable latencies on the >>>> MPC5200. It might also explain, why I get much worse latencies with >>>> 2.6.25.8-rt7. >>> Have you tried turning on ftrace? >> Hm, is it available for PowerPC? I have not found yet how to enable it. > > Hmm, should be. But I need to test it on my PPC box first before I can > tell you for sure. If you don't see a way to enable it, perhaps I haven't > updated the config options for PPC yet.
I added HAVE_FTRACE and HAVE_DYNAMIC_FTRACE to "config PPC" but more seems to be missing, e.g. arch/powerpc/kernel/ftrace.c. Nevertheless, how would I trigger high latency events with ftrace. I there a description somewhere?
Wolfgang.
| |