From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757433AbYG1Prr (ORCPT ); Mon, 28 Jul 2008 11:47:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752068AbYG1Prk (ORCPT ); Mon, 28 Jul 2008 11:47:40 -0400 Received: from chilli.pcug.org.au ([203.10.76.44]:57177 "EHLO smtps.tip.net.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751542AbYG1Prj (ORCPT ); Mon, 28 Jul 2008 11:47:39 -0400 Date: Tue, 29 Jul 2008 01:47:30 +1000 From: Stephen Rothwell To: eranian@googlemail.com Cc: linux-kernel@vger.kernel.org Subject: Re: [patch 00/19] perfmon2 minimal v3: introduction Message-Id: <20080729014730.76b879a4.sfr@canb.auug.org.au> In-Reply-To: <4868dbf6.0af5660a.1972.52f4@mx.google.com> References: <4868dbf6.0af5660a.1972.52f4@mx.google.com> X-Mailer: Sylpheed 2.5.0 (GTK+ 2.12.11; i486-pc-linux-gnu) Mime-Version: 1.0 Content-Type: multipart/signed; protocol="application/pgp-signature"; micalg="PGP-SHA1"; boundary="Signature=_Tue__29_Jul_2008_01_47_30_+1000_EIX.GyFJs.xJCciU" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --Signature=_Tue__29_Jul_2008_01_47_30_+1000_EIX.GyFJs.xJCciU Content-Type: text/plain; charset=US-ASCII Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi Stephane, On Mon, 30 Jun 2008 06:13:26 -0700 (PDT) eranian@googlemail.com wrote: > > The following patches implement a minimal perfmon2 subsystem which provid= es > access to the hardware performance counters of modern processors. First up, I cannot speak to the actual function of the patches, but just to the mechanics of getting them into the kernel. One good thing is that with CONFIG_PERFMON turned off, it looks like the impact is very close to zero. Two obvious things that would help these being accepted are: ordering - in the current incarnation, the patches produce places where the kernel will not build. We like things to be ordered so that git bisection does not fail if at all possible - that means that an allmod/yesconfig should build after the application of each patch. Currently this is not so. It could be mode to do so trivially by delaying the "global" Kconfig/Makefile updates until later in the sequence. And you really should introduce the system calls *before* wiring them up. quite a few of the macros (especially for the dummy (non CONFIG_PERFMON) versions of functions) should be "static inline" functions unless they absolutely must be macros. Andrew Morton said it best - "write in C not C preprocessor". I can see that this infrastructure could be very useful and I appreciate that it has been cut down for this initial merge. These patches (even as they are) compare favourably to some other new infrastructure that has been introduced. --=20 Cheers, Stephen Rothwell sfr@canb.auug.org.au http://www.canb.auug.org.au/~sfr/ --Signature=_Tue__29_Jul_2008_01_47_30_+1000_EIX.GyFJs.xJCciU Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) iEYEARECAAYFAkiN6hIACgkQjjKRsyhoI8zEhwCeNeV0y52N1Nz3MBhOsZn2bGr7 GcYAoLc0S1M732v9F6VZ1By0QYQiYrkp =g60t -----END PGP SIGNATURE----- --Signature=_Tue__29_Jul_2008_01_47_30_+1000_EIX.GyFJs.xJCciU--