From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753218AbaBKAMR (ORCPT ); Mon, 10 Feb 2014 19:12:17 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:59956 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753082AbaBKAL4 (ORCPT ); Mon, 10 Feb 2014 19:11:56 -0500 Date: Mon, 10 Feb 2014 16:13:10 -0800 From: Greg Kroah-Hartman To: Sudeep Holla Cc: "linux-kernel@vger.kernel.org" , Rob Herring , "linux-doc@vger.kernel.org" Subject: Re: [PATCH RFC/RFT v2 1/8] drivers: base: support cpu cache information interface to userspace via sysfs Message-ID: <20140211001310.GB3692@kroah.com> References: <1391791763-28518-1-git-send-email-sudeep.holla@arm.com> <1391791763-28518-2-git-send-email-sudeep.holla@arm.com> <20140207192925.GB18771@kroah.com> <52F915F6.9000501@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <52F915F6.9000501@arm.com> User-Agent: Mutt/1.5.22 (2013-10-16) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 10, 2014 at 06:09:58PM +0000, Sudeep Holla wrote: > On 07/02/14 19:29, Greg Kroah-Hartman wrote: > > On Fri, Feb 07, 2014 at 04:49:16PM +0000, Sudeep Holla wrote: > >> From: Sudeep Holla > >> > >> This patch adds initial support for providing processor cache information > >> to userspace through sysfs interface. This is based on already existing > >> implementations(x86, ia64, s390 and powerpc) and hence the interface is > >> intended to be fully compatible. > >> > >> The main purpose of this generic support is to avoid further code > >> duplication to support new architectures and also to unify all the existing > >> different implementations. > >> > >> This implementation maintains the hierarchy of cache objects which reflects > >> the system's cache topology. Cache objects are instantiated as needed as > >> CPUs come online. The cache objects are replicated per-cpu even if they are > >> shared. A per-cpu array of cache information maintained is used mainly for > >> sysfs-related book keeping. > > > > I thought I asked that you not use "raw" kobjects for this, instead > > using 'struct device' or just an attribute group? > > > > Correct, sorry I should have mentioned here instead of cover letter that it's > not yet done. Since the changes involved other architectures, I posted v2 to get > early feedback and testing. More over it's one place to fix now instead of 4 > unlike before. Ok, I'll wait to review it after you do the device conversion. > Just adding cache as a device as you suggested won't suffice here. As we need to > track multiple cache indices for each cpu, devices are needed for each cache > index. I tried using device_create_with_groups which provides all we need in one > api for cache indices but since cpu devices are not associated with any class, > it fails if class is NULL. Any suggestions ? Make the cpu devices be part of a class? thanks, greg k-h