Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752654Ab3GHQsK (ORCPT ); Mon, 8 Jul 2013 12:48:10 -0400 Received: from merlin.infradead.org ([205.233.59.134]:38372 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752517Ab3GHQsI (ORCPT ); Mon, 8 Jul 2013 12:48:08 -0400 Date: Mon, 8 Jul 2013 18:47:21 +0200 From: Peter Zijlstra To: Vince Weaver Cc: linux-kernel@vger.kernel.org, Paul Mackerras , Ingo Molnar , Arnaldo Carvalho de Melo Subject: Re: perf: more ABI breakage Message-ID: <20130708164721.GC22923@dyad.programming.kicks-ass.net> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1322 Lines: 34 On Mon, Jul 08, 2013 at 11:24:18AM -0400, Vince Weaver wrote: > > I guess I should have been noisier about this at the time. > > Linux 3.9 came with commit > e259514eef764a5286873618e34c560ecb6cff13 > that enabled AMD fam15h Northbridge support, by exposing the events as > part of the core CPU. > > Then Linux 3.10 changed this with > c43ca5091a374c1f6778bd7e4a39a5a10735a917 > and split them out as a separate PMU. > > This of course breaks libpfm4 and thus PAPI Urgh, so the 3.9 patches should never have been merged and sunk in while I was doing my vegetable imitation. Stephane agreed with the change in 3.10; and I suppose he overlooked the fact that people were already using it :/ I specifically asked if there were already users as that would indeed require some form of backwards compatibility -- however annoying. But to answer your question, no we should not blindly break stuff like this -- but yeah it would have been ever so much more useful for people to report this before we ship a release. Stephane; do you see a sane way to bridge this now? -- 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/