Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751689Ab2HCJcc (ORCPT ); Fri, 3 Aug 2012 05:32:32 -0400 Received: from hqemgate03.nvidia.com ([216.228.121.140]:1908 "EHLO hqemgate03.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751192Ab2HCJcb convert rfc822-to-8bit (ORCPT ); Fri, 3 Aug 2012 05:32:31 -0400 X-PGP-Universal: processed; by hqnvupgp05.nvidia.com on Fri, 03 Aug 2012 02:32:30 -0700 From: Venu Byravarasu To: Venu Byravarasu , Vikram Pandita , "gregkh@linuxfoundation.org" , "kay@vrfy.org" CC: "linux-kernel@vger.kernel.org" , Mike Turquette , Vimarsh Zutshi Date: Fri, 3 Aug 2012 15:02:26 +0530 Subject: RE: [PATCH v2] printk: add option to print cpu id Thread-Topic: [PATCH v2] printk: add option to print cpu id Thread-Index: Ac1xWMtvTs8UoHTwQBiUNqGfW2tFVwAALGNQAABG9iA= Message-ID: References: <1343985378-22330-1-git-send-email-vikram.pandita@ti.com> In-Reply-To: Accept-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US MIME-Version: 1.0 Content-Language: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2780 Lines: 63 > -----Original Message----- > From: linux-kernel-owner@vger.kernel.org [mailto:linux-kernel- > owner@vger.kernel.org] On Behalf Of Venu Byravarasu > Sent: Friday, August 03, 2012 2:58 PM > To: Vikram Pandita; gregkh@linuxfoundation.org; kay@vrfy.org > Cc: linux-kernel@vger.kernel.org; Mike Turquette; Vimarsh Zutshi > Subject: RE: [PATCH v2] printk: add option to print cpu id > > > -----Original Message----- > > From: linux-kernel-owner@vger.kernel.org [mailto:linux-kernel- > > owner@vger.kernel.org] On Behalf Of Vikram Pandita > > Sent: Friday, August 03, 2012 2:46 PM > > To: gregkh@linuxfoundation.org; kay@vrfy.org > > Cc: linux-kernel@vger.kernel.org; Vikram Pandita; Mike Turquette; Vimarsh > > Zutshi > > Subject: [PATCH v2] printk: add option to print cpu id > > > > From: Vikram Pandita > > > > Introduce config option to enable CPU id reporting for printk() calls. > > > > Example logs with this option enabled look like: > > [1] [ 2.328613] usbcore: registered new interface driver libusual > > [1] [ 2.335418] usbcore: registered new interface driver usbtest > > [1] [ 2.342803] mousedev: PS/2 mouse device common for all mice > > [0] [ 2.352600] twl_rtc twl_rtc: Power up reset detected. > > [0] [ 2.359191] twl_rtc twl_rtc: Enabling TWL-RTC > > [1] [ 2.367797] twl_rtc twl_rtc: rtc core: registered twl_rtc as rtc0 > > [1] [ 2.375274] i2c /dev entries driver > > [1] [ 2.382324] Driver for 1-wire Dallas network protocol. > > > > Its sometimes very useful to have printk also print the CPU Identifier > > that executed the call. This has helped to debug various SMP issues on > > shipping > > products. > As having Macro locally in the file of interest would serve the purpose, Why to change the printk code? > Is it not better to have macros which will have wrapper to printk with > required > debug info added? E.g. cpu# in your case. > If by default we add cupid, is it not over head in each message getting > printed with printk? > > > > > Known limitation is if the system gets preempted between function call and > > actual printk, the reported cpu-id might not be accurate. But most of the > > times its seen to give a good feel of how the N cpu's in the system are > > getting loaded. > > > -- > 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/ -- 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/