Re: [PATCH 1/2] perf, x86-mm: Add exit-fault tracing

From: Peter Zijlstra
Date: Thu Oct 27 2016 - 10:40:42 EST


On Wed, Oct 26, 2016 at 04:53:39PM -0200, Arnaldo Carvalho de Melo wrote:
> Em Wed, Oct 26, 2016 at 10:51:16AM +0200, Peter Zijlstra escreveu:
> > On Wed, Oct 26, 2016 at 01:51:59AM +0200, Alexis Berlemont wrote:
> >
> > -ENOCHANGELOG
>
> Yeah, please add one explaining why we want this, how we can use it, for
> example, in 'perf trace', to measure how long each page fault took,
> examples of it in use, etc.

Note that 'to measure page-fault duration' is not a reason, its a what.
This needs a proper reason.