From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751475AbaGLFdd (ORCPT ); Sat, 12 Jul 2014 01:33:33 -0400 Received: from mga01.intel.com ([192.55.52.88]:63530 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751136AbaGLFdc (ORCPT ); Sat, 12 Jul 2014 01:33:32 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.01,647,1400050800"; d="scan'208";a="560813312" Message-ID: <53C0C8A8.6020102@intel.com> Date: Sat, 12 Jul 2014 08:33:28 +0300 From: Adrian Hunter User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: Peter Zijlstra CC: acme@kernel.org, Jiri Olsa , Ingo Molnar , linux-kernel@vger.kernel.org, Frederic Weisbecker , David Ahern , "Shishkin, Alexander" , Paul Mackerras , Namhyung Kim , Stephane Eranian Subject: Re: perf tools: Call graph from Intel BTS References: <53BFF679.2030006@intel.com> <20140711153626.GP20603@laptop.programming.kicks-ass.net> In-Reply-To: <20140711153626.GP20603@laptop.programming.kicks-ass.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/07/2014 6:36 p.m., Peter Zijlstra wrote: > On Fri, Jul 11, 2014 at 05:36:41PM +0300, Adrian Hunter wrote: >> Alexander Shishkin is working on the Intel PT driver for perf >> and has included a driver for Intel BTS. I have taken that and > > There is already a BTS driver, although I've not used it ever, since > there's no useful tool for it. One way would be to use that, and migrate > to PT data later. Currently that driver does not allow kernel tracing. Last time I tried it with that restriction removed, it would lose data on larger workloads. Generally, any loss of data ruins the call graph. For me it does not make sense to try to support it, since I am primarily trying to pave the way for the Intel PT driver.