Re: 2.6.24-rc8-rt1: Strange latencies on mpc5200 powerpc - RCU issue?

From: Steven Rostedt
Date: Sat Jul 05 2008 - 20:42:02 EST



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.

-- Steve

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