From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754381AbZAIDaq (ORCPT ); Thu, 8 Jan 2009 22:30:46 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751816AbZAIDah (ORCPT ); Thu, 8 Jan 2009 22:30:37 -0500 Received: from tomts22-srv.bellnexxia.net ([209.226.175.184]:41298 "EHLO tomts22-srv.bellnexxia.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751811AbZAIDag (ORCPT ); Thu, 8 Jan 2009 22:30:36 -0500 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AiIHALVRZklMQWjN/2dsb2JhbACBbJJ+ul2FdQ Date: Thu, 8 Jan 2009 22:30:22 -0500 From: Mathieu Desnoyers To: Zhaolei Cc: ltt-dev@lists.casi.polymtl.ca, linux-kernel@vger.kernel.org, Andrew Morton , Greg KH Subject: Re: [ltt-dev] [PATCH 1/2] Make lttctl mount debugfs automatically Message-ID: <20090109033021.GA25504@Krystal> References: <49646208.7070607@cn.fujitsu.com> <4964BA2B.30200@polymtl.ca> <20090108144430.GA3778@Krystal> <7C0A417AB5B84CDCB9A9484C4E13A08C@zhaoleiwin> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline In-Reply-To: <7C0A417AB5B84CDCB9A9484C4E13A08C@zhaoleiwin> X-Editor: vi X-Info: http://krystal.dyndns.org:8080 X-Operating-System: Linux/2.6.21.3-grsec (i686) X-Uptime: 22:28:15 up 8 days, 3:26, 2 users, load average: 0.13, 0.16, 0.13 User-Agent: Mutt/1.5.16 (2007-06-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Zhaolei (zhaolei@cn.fujitsu.com) wrote: > * From: "Mathieu Desnoyers" > >* Zhaolei (zhaolei@cn.fujitsu.com) wrote: > >> * From: "Pierre-Marc Fournier" > >> > Zhaolei wrote: > >> >> lttctl need debugfs mounted, > >> >> This patch make lttctl mount debugfs automatically when it is not mounted. > >> >> > >> > > >> > Isn't having a utility such as lttctl mount filesystems against standard > >> > unix semantics? Can you give an example of another standard command that > >> > uses a filesystem and that tries to mount it if it isn't already > >> > mounted? > >> Hello, Pierre-Marc, > >> > >> I can give a an example. > >> It is SystemTap. > >> > > > > No offence, but can you find an example which is not explicitly > > described as "bad taste" example by many people in the Linux kernel > > community ? > Hello, Mathieu > > I can't find another example of mounting debugfs automatically. > Maybe it is because debugfs is not widely used as others such as sysfs and > procfs. > > sysfs and procfs are mounted in boot, and user-mode tools need not check and > mount then again. But debugfs is not too useful for normal user who just use > linux to edit text and browse internet, so mount debugfs in boot period is not > a good idea. > So, IMHO, debugfs's usage is not same as sysfs and procfs, we need not mount > sysfs and procfs in user-mode program, but maybe it is different for debugfs. > > On the other hand, I also understand your opinion, mount a fs in program looks > strange(but can make user easy to use...), so you can feel free to ignore this > patch. > Same with [PATCH 2/2] Make lttctl load ltt-trace-control module automatically. > I wonder what's Greg KH (and others) opinion about this ? Mathieu > Regards > Zhaolei > > > > > Mathieu > > > >> Regards > >> Zhaolei > >> > >> > My guess is we should warn about the filesystem not being > >> > mounted, but not try to call mount() directly. > >> > > >> >> Little cleanup also done(combile 2 getdebugfsmntdir() into one). > >> >> > >> >> Applies on top of ltt-control-0.63-03012009. > >> >> > >> > > >> > > >> _______________________________________________ > >> ltt-dev mailing list > >> ltt-dev@lists.casi.polymtl.ca > >> http://lists.casi.polymtl.ca/cgi-bin/mailman/listinfo/ltt-dev > >> > > > > -- > > Mathieu Desnoyers > > OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68 > > > > > _______________________________________________ > ltt-dev mailing list > ltt-dev@lists.casi.polymtl.ca > http://lists.casi.polymtl.ca/cgi-bin/mailman/listinfo/ltt-dev > -- Mathieu Desnoyers OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68