From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754561Ab1KHNBd (ORCPT ); Tue, 8 Nov 2011 08:01:33 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:33385 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753510Ab1KHNBb (ORCPT ); Tue, 8 Nov 2011 08:01:31 -0500 Date: Tue, 8 Nov 2011 13:59:32 +0100 From: Ingo Molnar To: Peter Zijlstra Cc: Pekka Enberg , "Frank Ch. Eigler" , "Ted Ts'o" , Vince Weaver , Pekka Enberg , Anthony Liguori , Avi Kivity , "kvm@vger.kernel.org list" , "linux-kernel@vger.kernel.org List" , qemu-devel Developers , Alexander Graf , Blue Swirl , =?iso-8859-1?Q?Am=E9rico?= Wang , Linus Torvalds , Arnaldo Carvalho de Melo Subject: Re: [F.A.Q.] perf ABI backwards and forwards compatibility Message-ID: <20111108125932.GC1022@elte.hu> References: <20111107175942.GA9395@elte.hu> <20111107203514.GG24234@thunk.org> <20111108102235.GA1241@elte.hu> <20111108113150.GA13195@redhat.com> <20111108121501.GA1022@elte.hu> <1320754825.11519.0.camel@twins> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1320754825.11519.0.camel@twins> User-Agent: Mutt/1.5.21 (2010-09-15) X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=AWL,BAYES_00 autolearn=no SpamAssassin version=3.3.1 -2.0 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] 0.0 AWL AWL: From: address is in the auto white-list Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Peter Zijlstra wrote: > On Tue, 2011-11-08 at 13:15 +0100, Ingo Molnar wrote: > > > > The one notable thing that isnt being tested in a natural way is > > the 'group of events' abstraction - which, ironically, has been > > added on the perfmon guys' insistence. No app beyond the PAPI > > self-test makes actual use of it though, which results in an > > obvious lack of testing. > > Also the self monitor stuff, perf-tool doesn't use that for obvious > reasons. Indeed, and that's PAPI's strong point. We could try to utilize it via some clever LD_PRELOAD trickery? Adding a testcase for every bug that can be triggered via tooling would definitely be an improvement as well - those kinds of testcases generally tend to map out the really important bits faster than an attempt at exhaustive testing. Thanks, Ingo From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:52263) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RNlJ0-0007W6-4G for qemu-devel@nongnu.org; Tue, 08 Nov 2011 08:01:34 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1RNlIt-0003oM-FM for qemu-devel@nongnu.org; Tue, 08 Nov 2011 08:01:33 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:59374) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RNlIt-0003nN-2d for qemu-devel@nongnu.org; Tue, 08 Nov 2011 08:01:27 -0500 Date: Tue, 8 Nov 2011 13:59:32 +0100 From: Ingo Molnar Message-ID: <20111108125932.GC1022@elte.hu> References: <20111107175942.GA9395@elte.hu> <20111107203514.GG24234@thunk.org> <20111108102235.GA1241@elte.hu> <20111108113150.GA13195@redhat.com> <20111108121501.GA1022@elte.hu> <1320754825.11519.0.camel@twins> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1320754825.11519.0.camel@twins> Subject: Re: [Qemu-devel] [F.A.Q.] perf ABI backwards and forwards compatibility List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Zijlstra Cc: Alexander Graf , Ted Ts'o , Arnaldo Carvalho de Melo , "kvm@vger.kernel.org list" , qemu-devel Developers , Vince Weaver , "linux-kernel@vger.kernel.org List" , Pekka Enberg , Blue Swirl , "Frank Ch. Eigler" , Pekka Enberg , Avi Kivity , =?iso-8859-1?Q?Am=E9rico?= Wang , Linus Torvalds * Peter Zijlstra wrote: > On Tue, 2011-11-08 at 13:15 +0100, Ingo Molnar wrote: > > > > The one notable thing that isnt being tested in a natural way is > > the 'group of events' abstraction - which, ironically, has been > > added on the perfmon guys' insistence. No app beyond the PAPI > > self-test makes actual use of it though, which results in an > > obvious lack of testing. > > Also the self monitor stuff, perf-tool doesn't use that for obvious > reasons. Indeed, and that's PAPI's strong point. We could try to utilize it via some clever LD_PRELOAD trickery? Adding a testcase for every bug that can be triggered via tooling would definitely be an improvement as well - those kinds of testcases generally tend to map out the really important bits faster than an attempt at exhaustive testing. Thanks, Ingo