Re: unpredictability in scheduler test results -- still present

[Chris Friesen]

Ingo Molnar wrote:
> * Chris Friesen <cfriesen@xxxxxxxxxx> wrote:

> > It turns out that disabling CONFIG_DYNAMIC_FTRACE makes the load 
> > balancing problem go away and causes all cpus to be used.
> >
> > With this option enabled, the problem seems to be present as far back 
> > as 2.6.27-rc2.  (2.6.27-rc1 doesn't compile on my machine, and 2.6.26 
> > doesn't have ftrace).
> >
> > I have no idea why turning on dynamic ftrace would affect load 
> > balancing behaviour, but it's very repeatable.  The very first test 
> > run after booting works fine, and all successive runs fail to balance 
> > properly.

> OTOH, what does 'truning on dftrace' exactly mean? Just enabling it in 
> the .config, or also activating it via /debug/tracing/current_tracer?

Just enabling it in the .config is enough to trigger the behaviour 
change.  I'm not explicitly activating any traces.

Chris
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