From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1BCEDC2D0DB for ; Thu, 23 Jan 2020 15:53:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E3A71214AF for ; Thu, 23 Jan 2020 15:53:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728665AbgAWPxx (ORCPT ); Thu, 23 Jan 2020 10:53:53 -0500 Received: from outgoing-auth-1.mit.edu ([18.9.28.11]:32990 "EHLO outgoing.mit.edu" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726231AbgAWPxw (ORCPT ); Thu, 23 Jan 2020 10:53:52 -0500 Received: from callcc.thunk.org (rrcs-67-53-201-206.west.biz.rr.com [67.53.201.206]) (authenticated bits=0) (User authenticated as tytso@ATHENA.MIT.EDU) by outgoing.mit.edu (8.14.7/8.12.4) with ESMTP id 00NFrfhf029524 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 23 Jan 2020 10:53:43 -0500 Received: by callcc.thunk.org (Postfix, from userid 15806) id D1F7642014A; Thu, 23 Jan 2020 10:53:40 -0500 (EST) Date: Thu, 23 Jan 2020 10:53:40 -0500 From: "Theodore Y. Ts'o" To: Greg Kroah-Hartman Cc: Jason Baron , Will Deacon , linux-kernel@vger.kernel.org, kernel-team@android.com Subject: Re: [PATCH v3] dynamic_debug: allow to work if debugfs is disabled Message-ID: <20200123155340.GD147870@mit.edu> References: <20200122074343.GA2099098@kroah.com> <20200122080352.GA15354@willie-the-truck> <20200122081205.GA2227985@kroah.com> <20200122135352.GA9458@kroah.com> <8d68b75c-05b8-b403-0a10-d17b94a73ba7@akamai.com> <20200122192940.GA88549@kroah.com> <20200122193118.GA88722@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200122193118.GA88722@kroah.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 22, 2020 at 08:31:18PM +0100, Greg Kroah-Hartman wrote: > With the realization that having debugfs enabled on "production" systems is > generally not a good idea, debugfs is being disabled from more and more > platforms over time. However, the functionality of dynamic debugging still is > needed at times, and since it relies on debugfs for its user api, having > debugfs disabled also forces dynamic debug to be disabled. > > To get around this, move the "control" file for dynamic_debug to procfs IFF > debugfs is disabled. This lets people turn on debugging as needed at runtime > for individual driverfs and subsystems. Instead of moving the control file IFF debugfs is enabled, what about always making it available in /proc, and marking the control file for dynamic_debug in debugfs as deprecated? It would seem to me that this would cause less confusion in the future.... - Ted