Re: [PATCH v5 1/4] ftrace: Implement fs notification for tracing_max_latency

[Steven Rostedt]

On Wed, 4 Sep 2019 10:20:46 +0200
Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:

> On Tue, Sep 03, 2019 at 03:25:59PM +0200, Viktor Rosendahl wrote:
> 
> > It seems like it would be possible to simply replace the calls to
> > latency_fsnotify_enable/disable() with calls to
> > start/stop_critical_timings(). However, the main problem is that it
> > would not work for the wakup tracer. The wakeup tracer needs a
> > facility that postpones the notifications, not one that prevents the
> > measurements because all its measurements takes place in the middle
> > of __schedule(). On the other hand, in some places, like in idle and
> > the console we need start stop functions that prevents the
> > measurements from being make.  
> 
> Like Joel already mentioned; you can use irq_work here.

And I was thinking the exact same thing here too ;-)

-- Steve