From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnaldo Carvalho de Melo Subject: Re: Re: perf tracepoints for regular user? Date: Thu, 21 Jan 2016 11:05:05 -0300 Message-ID: <20160121140505.GB2312@kernel.org> References: <20160115210516.GA6329@localhost> <4927145.OUESRpdSEU@agathebauer> <20160119050244.GA13183@localhost> <20160119221858.GK27085@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail.kernel.org ([198.145.29.136]:38033 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759536AbcAUOFV (ORCPT ); Thu, 21 Jan 2016 09:05:21 -0500 Content-Disposition: inline In-Reply-To: Sender: linux-perf-users-owner@vger.kernel.org List-ID: To: Benjamin King Cc: linux-perf-users Em Wed, Jan 20, 2016 at 12:50:33PM +0100, Benjamin King escreveu: > Hi Arnaldo, > > > > $ sudo mount -o remount,mode=755 /sys/kernel/debug/tracing > > > mount: can't find /sys/kernel/debug/tracing in /etc/fstab > > > $ mount|grep debug > > > none on /sys/kernel/debug type debugfs (rw,mode=755,mode=755) > > > > Ok, your kernel is old and doesn't have the tracefs: Not having tracefs, if that is indeed the case, only means that the remount isn't needed, as what is in tracefs is what, before its existence, lived in a debugfs directory, /sys/kernel/debug/tracing, i.e. remounting just /sys/kernel/debug/ would then be enough. > > [acme@zoo ~]$ mount | egrep \(debug\|trace\)fs > > debugfs on /sys/kernel/debug type debugfs (rw,relatime,seclabel,mode=755) > > tracefs on /sys/kernel/debug/tracing type tracefs (rw,relatime,mode=755) > > [...] > > [acme@zoo ~]$ uname -r > > 4.3.0+ > That's odd. According to kernelnewbies.org (Yes, I am that much of a > kernel hacker :-) ), tracefs should be in since 4.1 and I'm on 4.2, > but I can only find CONFIG_DEBUG_FS in my kernel configuration. There > is no mentioning of a corresponding CONFIG_TRACE_FS there. > I'll try to upgrade to a more recent kernel and stop bugging you guys until then.