Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S943060AbcJ0Oke (ORCPT ); Thu, 27 Oct 2016 10:40:34 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:52312 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S936094AbcJ0Nuz (ORCPT ); Thu, 27 Oct 2016 09:50:55 -0400 Date: Thu, 27 Oct 2016 10:38:02 +0200 From: Peter Zijlstra To: Arnaldo Carvalho de Melo Cc: Alexis Berlemont , linux-kernel@vger.kernel.org, mingo@redhat.com, alexander.shishkin@linux.intel.com Subject: Re: [PATCH 1/2] perf, x86-mm: Add exit-fault tracing Message-ID: <20161027083802.GG3568@worktop.programming.kicks-ass.net> References: <20161025235200.28781-1-alexis.berlemont@gmail.com> <20161025235200.28781-2-alexis.berlemont@gmail.com> <20161026085116.GZ3102@twins.programming.kicks-ass.net> <20161026185339.GC4704@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161026185339.GC4704@kernel.org> User-Agent: Mutt/1.5.22.1 (2013-10-16) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 515 Lines: 12 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.