Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751349AbWJ1SlE (ORCPT ); Sat, 28 Oct 2006 14:41:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751350AbWJ1SlE (ORCPT ); Sat, 28 Oct 2006 14:41:04 -0400 Received: from gprs189-60.eurotel.cz ([160.218.189.60]:39180 "EHLO spitz.ucw.cz") by vger.kernel.org with ESMTP id S1751349AbWJ1SlC (ORCPT ); Sat, 28 Oct 2006 14:41:02 -0400 Date: Sat, 28 Oct 2006 18:40:48 +0000 From: Pavel Machek To: Michael Holzheu Cc: Ingo Oeser , linux-kernel@vger.kernel.org, mschwid2@de.ibm.com Subject: Re: How to document dimension units for virtual files? Message-ID: <20061028184048.GB5152@ucw.cz> References: <200610232103.33710.ioe-lkml@rameria.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1722 Lines: 51 Hi! > > > 2. Encode dimension unit into filename (e.g. onlinetime_ms or > memory_kb) > > > > This is the recommended one. > > - simple to implement and understand on both sides > > > > - if you change units, you notice breaking userspace immediately > > and can even notice it being used in closed source tools > > with a simple strace > > > > - no parsing involved, as the author of the user space tool > > usually assumes the unit implicitly (like "programming by contract", > where > > the "contract" is the filename, which is quite easy to check for. > > > > - you can keep a legacy interface with neglible effort and code wastage > > > > - many advantages I forgot :-) > > > > I also think that this is the best solution. It would be nice to have > that documented somewhere. Maybe in the Documentation directory > something like: > > Howto export data in virtual files > ================================== > > If you want to export data to userspace via virtual filesystems > like procfs, sysfs, debugfs etc., the following rules are recommended: ...yes please... such patch would be nice. > - Export only one value in one virtual file. > - Data format should be as simple as possible. > - Use ASCII formated strings, no binary data if possible. > - If data has dimension units, encode that in the filename. > Please use the following suffixes: > * kb: Kilobytes > * mb: Megabytes just use B for bytes.... -- Thanks for all the (sleeping) penguins. - 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/