Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758435Ab3EOLrk (ORCPT ); Wed, 15 May 2013 07:47:40 -0400 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:37778 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753646Ab3EOLrj (ORCPT ); Wed, 15 May 2013 07:47:39 -0400 Date: Wed, 15 May 2013 13:47:37 +0200 From: Pavel Machek To: Will Deacon Cc: Nicolas Pitre , Rob Herring , Marc Zyngier , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" Subject: Re: [RFC PATCH 1/2] ARM: delay: print dummy values for bogomips Message-ID: <20130515114737.GA7900@amd.pavel.ucw.cz> References: <1367602547-19322-1-git-send-email-will.deacon@arm.com> <1367602547-19322-2-git-send-email-will.deacon@arm.com> <20130506231554.GB16801@amd.pavel.ucw.cz> <5188B8B2.5030601@arm.com> <20130515090103.GA12907@mudshark.cambridge.arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130515090103.GA12907@mudshark.cambridge.arm.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1867 Lines: 48 On Wed 2013-05-15 10:01:03, Will Deacon wrote: > Hi Nico, > > On Wed, May 15, 2013 at 12:56:51AM +0100, Nicolas Pitre wrote: > > On Tue, 14 May 2013, Rob Herring wrote: > > > On Tue, May 14, 2013 at 2:54 PM, Nicolas Pitre wrote: > > > > Waitaminute... Didn't you just claim this would be an ABI break? > > > > > > > > So if no application can be found, where is the ABI breakage? > > > > > > lscpu > > > > > > But that is already "broken" on ARM because x86 uses "bogomips" and > > > ARM uses "BogoMIPS". > > > > So basically it won't be any more broken if the field disappears > > entirely, right? > > It's not these sort of tools I was worried about. I was thinking about the > possibility of badly written parsers which want some other field from > cpuinfo, but use the bogomips line for context. Do these applications exist? > No idea. Yes, they do. bogomips is not nearly as bogus as you imply. See http://www.clifton.nl/index.html?bogomips.html https://play.google.com/store/apps/details?id=com.securiteinfo.android.bogomips&hl=en > My second (less stupid) version of the patch prints "not reported". I'd be > happy to remove the line altogether if people get behind the decision though. > In fact, I just tried it and at least my linaro filesystem seems happy > enough. Would it be too much work to simply put the field back with the right value? We don't have to get it as precise as we used to, that should make slowdown minimum. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- 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/