Re: Fix powerTOP regression with 2.6.39-rc5

[Arjan van de Ven]

On 5/7/2011 10:20 AM, Steven Rostedt wrote:
> On Sat, 2011-05-07 at 16:44 +0200, Ingo Molnar wrote:
> > * Steven Rostedt<rostedt@xxxxxxxxxxx>  wrote:
> >
> > > 2) we separate perf from ftrace and keep the "stable" ABI for perf, and let
> > > ftrace advance into a more efficient tracer.
> > The thing is, ftrace is still largely separated from perf, and this is why this
> > regression came in: a random tracing 'cleanup' churn was done to 'tracing'
> > which broke PowerTop.
> >
> > Look at the commit itself:
> >
> >    e6e1e2593592: tracing: Remove lock_depth from event entry
> >
> > Clearly you didnt even *realize* that there's a whole tooling world behind this
> > mechanism ...
> Note, I discussed this change with Frederic and he totally agreed with
> me on removing it. In fact, we are in discussions about getting rid of
> pid, preempt-count, and irq flags as well. But according to your logic,
> that is a no go. I guess Frederic also does not *realize* there's a
> whole tooling world behind this mechanism too.

btw if you remove some of these, how is userland supposed to find out if 
an event happened in irq context?


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