From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934161AbaLLSxa (ORCPT ); Fri, 12 Dec 2014 13:53:30 -0500 Received: from mail.kernel.org ([198.145.19.201]:47452 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932531AbaLLSx3 (ORCPT ); Fri, 12 Dec 2014 13:53:29 -0500 Date: Fri, 12 Dec 2014 15:53:24 -0300 From: Arnaldo Carvalho de Melo To: David Ahern Cc: Adrian Hunter , Peter Zijlstra , linux-kernel@vger.kernel.org, Frederic Weisbecker , Jiri Olsa , Namhyung Kim , Paul Mackerras , Stephane Eranian Subject: Re: [PATCH V3 00/22] perf tools: Introduce an abstraction for Instruction Tracing Message-ID: <20141212185324.GF9845@kernel.org> References: <1418392089-5568-1-git-send-email-adrian.hunter@intel.com> <548B1425.7090500@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <548B1425.7090500@gmail.com> X-Url: http://acmel.wordpress.com User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Fri, Dec 12, 2014 at 09:13:25AM -0700, David Ahern escreveu: > On 12/12/14 6:47 AM, Adrian Hunter wrote: > >Here is V3 of some more preparatory patches for Intel PT > >that introduce an abstraction for Instruction tracing. > This is an x86-Intel only feature correct? If that is the case then the code > should be not compiled for other architectures. My view so far is that what has been pushed for inclusion facilitates supporting an event stream that is so huge that needs to be mapped directly from hardware to tools, that would receive it in a special area obtained from perf_mmap(). What comes in those events? In this case, this Intel PT stuff, but noving (should) prevent it from being used for similar situations for other architectures. I wonder if we could somehow rename this from 'itrace' to some other more meaningful name given the above understanding of this being just a way to directly funnel events from hardware to userspace together with perf metadata (PERF_RECORD_FORK, PERF_RECORD_MMAP, etc) + other events. In the kernel this was called a "AUX" thing, which I also think is vague... - Arnaldo