From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760829AbbBIPGa (ORCPT ); Mon, 9 Feb 2015 10:06:30 -0500 Received: from smtprelay0081.hostedemail.com ([216.40.44.81]:45463 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1759789AbbBIPG3 (ORCPT ); Mon, 9 Feb 2015 10:06:29 -0500 X-Session-Marker: 6E657665747340676F6F646D69732E6F7267 X-Spam-Summary: 2,0,0,,d41d8cd98f00b204,rostedt@goodmis.org,:::::::::::,RULES_HIT:41:355:379:541:599:800:960:973:988:989:1260:1277:1311:1313:1314:1345:1359:1437:1515:1516:1518:1534:1541:1593:1594:1711:1730:1747:1777:1792:2198:2199:2393:2553:2559:2562:2689:2693:2895:3138:3139:3140:3141:3142:3353:3622:3865:3866:3867:3868:3870:3871:3872:3873:3874:4362:5007:6261:7576:7875:9040:10004:10400:10848:10967:11232:11658:11914:12517:12519:12740:13069:13141:13230:13255:13311:13357:14096:14097:21063:21080,0,RBL:none,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fn,MSBL:0,DNSBL:none,Custom_rules:0:0:0 X-HE-Tag: rose02_385fefc72461e X-Filterd-Recvd-Size: 2484 Date: Mon, 9 Feb 2015 10:06:26 -0500 From: Steven Rostedt To: Namhyung Kim Cc: linux-kernel@vger.kernel.org, Al Viro , Greg Kroah-Hartman , Ingo Molnar , Andrew Morton Subject: Re: [for-next][PATCH 5/7] tracing: Automatically mount tracefs on debugfs/tracing Message-ID: <20150209100626.46d4ba6a@gandalf.local.home> In-Reply-To: <20150209060002.GB30788@sejong> References: <20150204143420.290584004@goodmis.org> <20150204143755.694479564@goodmis.org> <20150209060002.GB30788@sejong> X-Mailer: Claws Mail 3.11.1 (GTK+ 2.24.25; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 9 Feb 2015 15:00:02 +0900 Namhyung Kim wrote: > On Wed, Feb 04, 2015 at 09:34:25AM -0500, Steven Rostedt wrote: > > From: "Steven Rostedt (Red Hat)" > > > > As tools currently rely on the tracing directory in debugfs, we can not > > just created a tracefs infrastructure and expect sysadmins to mount > > the new tracefs to have their old tools work. > > > > Instead, the debugfs tracing directory is still created and the tracefs > > file system is mounted there when the debugfs filesystem is mounted. > > > > No longer does the tracing infrastructure update the debugfs file system, > > but instead interacts with the tracefs file system. But now, it still > > appears to the user like nothing changed, except you also have the feature > > of mounting just the tracing system without needing all of debugfs! > > One question. Is it possible to have both of the old > /sys/kernel/debug/tracing and new /sys/kernel/tracing directories? Yes. In fact it's required. Because we must stay backward compatible with older tools, we can not get rid of the debug/tracing directory. > > + /* > > + * As there may still be users that expect the tracing > > + * files to exist in debugfs/tracing, we must automount > > + * the tracefs file system there, so older tools still > > + * work with the newer kerenl. > > s/kerenl/kernel/ Thanks, will fix. -- Steve