Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932242AbVL0Fhz (ORCPT ); Tue, 27 Dec 2005 00:37:55 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932241AbVL0Fhy (ORCPT ); Tue, 27 Dec 2005 00:37:54 -0500 Received: from mail.kroah.org ([69.55.234.183]:12194 "EHLO perch.kroah.org") by vger.kernel.org with ESMTP id S932232AbVL0Fhv (ORCPT ); Tue, 27 Dec 2005 00:37:51 -0500 Date: Mon, 26 Dec 2005 21:36:10 -0800 From: Greg KH To: Yanmin Zhang Cc: linux-kernel@vger.kernel.org, discuss@x86-64.org, linux-ia64@vger.kernel.org, "Siddha, Suresh B" , "Shah, Rajesh" , "Pallipadi, Venkatesh" , yanmin.zhang@intel.com Subject: Re: [PATCH v2:3/3]Export cpu topology by sysfs Message-ID: <20051227053610.GE25886@kroah.com> References: <8126E4F969BA254AB43EA03C59F44E84044DE5EA@pdsmsx404> <20051226002839.A24653@unix-os.sc.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20051226002839.A24653@unix-os.sc.intel.com> User-Agent: Mutt/1.5.11 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3490 Lines: 76 On Mon, Dec 26, 2005 at 12:28:39AM -0800, Yanmin Zhang wrote: > On Mon, Dec 26, 2005 at 03:38:16PM +0800, Zhang, Yanmin wrote: > > >>-----Original Message----- > > >>From: Greg KH [mailto:greg@kroah.com] > > >>Sent: 2005??12??24?? 3:16 > > >>To: Zhang, Yanmin > > >>Cc: Yanmin Zhang; linux-kernel@vger.kernel.org; discuss@x86-64.org; linux-ia64@vger.kernel.org; Siddha, Suresh B; Shah, Rajesh; > > >>Pallipadi, Venkatesh > > >>Subject: Re: [PATCH v2:3/3]Export cpu topology by sysfs > > >> > > >>On Fri, Dec 23, 2005 at 12:03:27PM +0800, Zhang, Yanmin wrote: > > >>> >>Can't you just use an attribute group and attach it to the cpu kobject? > > >>> >>That would save an array of kobjects I think. > > >>> As you know, current i386/x86_64 arch also export cache info under > > >>> /sys/device/system/cpu/cpuX/cache. Is it clearer to export topology > > >>> under a new directory than under cpu directly? > > >> > > >>No, the place in the sysfs tree you are putting this is just fine. I'm > > >>just saying that you do not need to create a new kobject for these > > >>attributes. Just use an attribute group, and you will get the same > > >>naming, without the need for an extra kobject (and the whole array of > > >>kobjects) at all. > > >> > > >>Does that make more sense? > > Yes, indeed. Now, I used your idea and the patch became simpler. Thanks. > > > > > > >> > > >>> >>> +static int __cpuinit topology_cpu_callback(struct notifier_block *nfb, > > >>> >>> + unsigned long action, void *hcpu) > > >>> >>> +{ > > >>> >>> + unsigned int cpu = (unsigned long)hcpu; > > >>> >>> + struct sys_device *sys_dev; > > >>> >>> + > > >>> >>> + sys_dev = get_cpu_sysdev(cpu); > > >>> >>> + switch (action) { > > >>> >>> + case CPU_ONLINE: > > >>> >>> + topology_add_dev(sys_dev); > > >>> >>> + break; > > >>> >>> +#ifdef CONFIG_HOTPLUG_CPU > > >>> >>> + case CPU_DEAD: > > >>> >>> + topology_remove_dev(sys_dev); > > >>> >>> + break; > > >>> >>> +#endif > > >>> >> > > >>> >>Why ifdef? Isn't it safe to just always have this in? > > >>> If no ifdef here, gcc reported a compiling warning when I compiled it > > >>> on IA64 with CONFIG_HOTPLUG_CPU=n. > > >> > > >>Then you should probably go change it so that CPU_DEAD is defined on > > >>non-smp builds, otherwise the code gets quite messy like the above :) > > > > Sorry. My previous explanation is confusing. It's a link warning on ia64. On ia64, the kernel vmlinux doesn't include section .exit.text, so ld will report a link warning when a function is in section .exit.text and another function (not in .exit.text) calls the first one. When CONFIG_HOTPLUG_CPU=n, function topology_remove_dev is in section .exit.text, but its caller topology_remove_dev is not in .exit.text. > > > > i386 and x86_64 kernel vmlinux does include .exit.text and discard it only when running, so there is no such warning on i386/x86_64. > > > > There is no other better approach to get rid of the warning unless we change arch/ia64/kernel/vmlinux.lds.S to keep all .exit.text in kernel image. > > Here is the new patch. Thank Greg. Much nicer, thanks for the changes. But you forgot the description and the Signed-off-by: line so that it can be picked up :( Care to try again? thanks, greg k-h - 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/