Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754916Ab0KIWWZ (ORCPT ); Tue, 9 Nov 2010 17:22:25 -0500 Received: from canuck.infradead.org ([134.117.69.58]:59048 "EHLO canuck.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753497Ab0KIWWX convert rfc822-to-8bit (ORCPT ); Tue, 9 Nov 2010 17:22:23 -0500 Subject: Re: [RFC][PATCH] perf: sysfs type id From: Peter Zijlstra To: Kay Sievers Cc: LKML , Ingo Molnar , Lin Ming , Stephane Eranian , "robert.richter" , Corey Ashford , fweisbec , paulus , Greg Kroah-Hartman , "H. Peter Anvin" In-Reply-To: References: <1289339119.2191.92.camel@laptop> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Date: Tue, 09 Nov 2010 23:22:27 +0100 Message-ID: <1289341347.2191.97.camel@laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1654 Lines: 39 On Tue, 2010-11-09 at 23:11 +0100, Kay Sievers wrote: > On Tue, Nov 9, 2010 at 22:45, Peter Zijlstra wrote: > > The below is a RFC patch adding dynamic type ids to perf. > > > > We need to represent PMUs in sysfs because we want to allow multiple > > (loadable) PMUs and need a way to identify them. > > > > This patch creates a new device class "pmu" and adds a single attribute > > "type" to it. This device attribute will expose the dynamic type id as > > required by perf_event_attr::type. > > > > The sysfs layout looks like: > > > > [root@westmere ~]# cd /sys/class/pmu/ > > Please use a 'bus_type' instead of 'class'. > > I'm very sure, some day, you'll need global attributes for the pmu > stuff, and class -- unlike bus -- has its own subdir where you can go > wild, without mixing things with the list-of-devices. :) Having its own subdir sounds like a pro, so I'm somewhat confused. Also the pmu (or event_source as Ingo would like it getting called) seems like a class of devices not a bus. USB/PCI/I2C/ISA are all buses.. pmu/event_source not so much, they are very different (sometimes even pure software) things that provide a common interface -- they generate events which we can count and sample. /me dazed & confused, please do explain. > No new stuff should use 'class', it's not extensible. Hrm.. when I introduced the bdi stuff class was _the_ thing to use. -- 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/