From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BFEE727EFF3; Tue, 17 Jun 2025 18:00:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.92.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750183240; cv=none; b=c6goqjvQWJiDO8yL/YIsuZzCg4ZK6I8/XCDXxXC2GRLcFzo1z9NFnDKiLYPfdEwgaoG21h+cT2vHsizdEjn38oT6fLEmuLMqwpcjNlBYT9yO8o1qnh3kkbr4kQfY1RqLneDblSYgIwP4bJx7dz5uHuCOGeI1DTEpya+Wen1YUIo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750183240; c=relaxed/simple; bh=pkZOwsH82D8u896EvU2FuOaGI/j15LZGRQ78QCy5HA0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=pv5ppnPJ1k4BWexsTiLHR06n6jMQHbsnaI3lQV3NwnNVanYKx/aDgXM6S1pW1ascdkVwFvjPMxiWwqxxVTynbtIJpFCIywdYAkEZor0uKbreBDfO9qC0PwtssBRyblBFwWaeVQd7TJdXjut7cWr6lGVVZTL2hbkUMUyT7hGhj9Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=UEvTXiAV; arc=none smtp.client-ip=90.155.92.199 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="UEvTXiAV" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=PpPXOSCDFfvOCX6jYgFEFRb0EH0bOjsYTT1mkenvM2Q=; b=UEvTXiAVnGCcwP9U0zCSYtNoOg C+YuH8rtvDDU3mFEvey5JQWriciZ2BASvA3Da8QpGZD/MxtLmFLxqItoIRVSFiHhurWiFunWaU+Sc WOOXg6EntegwyBMTSCvq5AEi9FhUS+Z/HhS7faukd8vq0W/iJHVp4kEL8zrycTmxT3ESWt73wCNh0 98NMLJ3s50xcjIjBAwTG+crkwcZureCyvzcdqF9XfHg7HgQyb3wcw9KvoXi3fVyIT9n0BTLSjjX9J RQKaNDI7POcRFDnZP7ZLbRojcOvPB7JyRoP0lcZTvOW72eZfrhTfMa4Odcal4FGxgc9yTr5Vq4e2a n4syALuA==; Received: from 2001-1c00-8d82-d000-266e-96ff-fe07-7dcc.cable.dynamic.v6.ziggo.nl ([2001:1c00:8d82:d000:266e:96ff:fe07:7dcc] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux)) id 1uRabh-00000003sCo-2zkw; Tue, 17 Jun 2025 18:00:26 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id C710330BDAD; Tue, 17 Jun 2025 20:00:23 +0200 (CEST) Date: Tue, 17 Jun 2025 20:00:23 +0200 From: Peter Zijlstra To: Steven Rostedt Cc: LKML , Linux Trace Kernel , "linux-trace-users@vger.kernel.org" , linux-fsdevel@vger.kernel.org, linux-perf-users@vger.kernel.org, Masami Hiramatsu , Mathieu Desnoyers , Mark Rutland , Thomas Gleixner , Sebastian Andrzej Siewior , Namhyung Kim , Linus Torvalds , Andrew Morton , Greg Kroah-Hartman , Al Viro , Christian Brauner , Jan Kara , Arnaldo Carvalho de Melo , Frederic Weisbecker , Jiri Olsa , Ian Rogers Subject: Re: [RFC][PATCH] tracing: Deprecate auto-mounting tracefs in debugfs Message-ID: <20250617180023.GC1613376@noisy.programming.kicks-ass.net> References: <20250617133614.24e2ba7f@gandalf.local.home> <20250617174107.GB1613376@noisy.programming.kicks-ass.net> <3201A571-6F08-4E26-AC33-39E0D1925D27@goodmis.org> Precedence: bulk X-Mailing-List: linux-trace-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3201A571-6F08-4E26-AC33-39E0D1925D27@goodmis.org> On Tue, Jun 17, 2025 at 01:54:46PM -0400, Steven Rostedt wrote: > > > On June 17, 2025 1:41:07 PM EDT, Peter Zijlstra wrote: > >On Tue, Jun 17, 2025 at 01:36:14PM -0400, Steven Rostedt wrote: > >> From: Steven Rostedt > >> > >> In January 2015, tracefs was created to allow access to the tracing > >> infrastructure without needing to compile in debugfs. When tracefs is > >> configured, the directory /sys/kernel/tracing will exist and tooling is > >> expected to use that path to access the tracing infrastructure. > >> > >> To allow backward compatibility, when debugfs is mounted, it would > >> automount tracefs in its "tracing" directory so that tooling that had hard > >> coded /sys/kernel/debug/tracing would still work. > >> > >> It has been over 10 years since the new interface was introduced, and all > >> tooling should now be using it. Start the process of deprecating the old > >> path so that it doesn't need to be maintained anymore. > > > >I've always used /debug/tracing/ (because /debug is the right place to > >mount debugfs). You're saying this is going away and will break all my > >scripts?! > > You could mount tracefs in /tracing too: > > # mount -t tracefs nodev /tracing > > And update you scripts with a simple sed script. If I have to edit the mount table, I'll just keep it at /debug/tracing/. Tracing is very much debug stuff anyway. While I knew there was tracefs, I never knew there was another mount point. Just annoying I now have to add two entries to every new machine.. Oh well.