Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755944Ab1EGR7n (ORCPT ); Sat, 7 May 2011 13:59:43 -0400 Received: from mga02.intel.com ([134.134.136.20]:41194 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752865Ab1EGR7i (ORCPT ); Sat, 7 May 2011 13:59:38 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.64,331,1301900400"; d="scan'208";a="743775253" Message-ID: <4DC58888.9030402@linux.intel.com> Date: Sat, 07 May 2011 10:59:36 -0700 From: Arjan van de Ven User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2.17) Gecko/20110414 Thunderbird/3.1.10 MIME-Version: 1.0 To: Steven Rostedt CC: Ingo Molnar , David Sharp , Vaibhav Nagarnaik , Michael Rubin , Linus Torvalds , linux-kernel , Frederic Weisbecker , Peter Zijlstra , Thomas Gleixner Subject: Re: Fix powerTOP regression with 2.6.39-rc5 References: <4DC45537.6070609@linux.intel.com> <1304713252.25414.2532.camel@gandalf.stny.rr.com> <20110507065803.GA23414@elte.hu> <1304765110.25414.2564.camel@gandalf.stny.rr.com> <20110507144402.GC2859@elte.hu> <1304788829.11129.57.camel@frodo> In-Reply-To: <1304788829.11129.57.camel@frodo> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1365 Lines: 31 On 5/7/2011 10:20 AM, Steven Rostedt wrote: > On Sat, 2011-05-07 at 16:44 +0200, Ingo Molnar wrote: >> * Steven Rostedt wrote: >> >>> 2) we separate perf from ftrace and keep the "stable" ABI for perf, and let >>> ftrace advance into a more efficient tracer. >> The thing is, ftrace is still largely separated from perf, and this is why this >> regression came in: a random tracing 'cleanup' churn was done to 'tracing' >> which broke PowerTop. >> >> Look at the commit itself: >> >> e6e1e2593592: tracing: Remove lock_depth from event entry >> >> Clearly you didnt even *realize* that there's a whole tooling world behind this >> mechanism ... > Note, I discussed this change with Frederic and he totally agreed with > me on removing it. In fact, we are in discussions about getting rid of > pid, preempt-count, and irq flags as well. But according to your logic, > that is a no go. I guess Frederic also does not *realize* there's a > whole tooling world behind this mechanism too. btw if you remove some of these, how is userland supposed to find out if an event happened in irq context? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/