Re: [PATCH v2] tracing: Don't account for cpu idle time with irqsoff tracers

From: Steven Rostedt
Date: Wed May 28 2014 - 10:09:18 EST


On Wed, 28 May 2014 09:28:52 +0200
Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:

> On Tue, May 27, 2014 at 07:30:50PM -0400, Steven Rostedt wrote:
> > Paul, Peter, see anything wrong with this?
>
> You mean, aside from that it won't actually apply due to that code
> having been massively overhauled?
>
> I suppose the same thing Arnd mentioned, the cpuidle_enter() thing can
> be huge, but is we're going to have to push this down into all cpuidle
> drivers we're not going to be happy.
>

I believe that the stop/start_critical_timings() can nest. If not, I
can make them do so. Thus, we could start adding them in the depths of
the cpuidle drivers. If we miss one, we may not notice until someone
reports a large latency due to it. And that is only if the driver
itself calls local_irq_save/restore().

-- Steve
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