From: Steven Rostedt <rostedt@goodmis.org>
To: Namhyung Kim <namhyung@kernel.org>
Cc: linux-kernel@vger.kernel.org, Al Viro <viro@ZenIV.linux.org.uk>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Ingo Molnar <mingo@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [for-next][PATCH 5/7] tracing: Automatically mount tracefs on debugfs/tracing
Date: Mon, 9 Feb 2015 10:06:26 -0500 [thread overview]
Message-ID: <20150209100626.46d4ba6a@gandalf.local.home> (raw)
In-Reply-To: <20150209060002.GB30788@sejong>
On Mon, 9 Feb 2015 15:00:02 +0900
Namhyung Kim <namhyung@kernel.org> wrote:
> On Wed, Feb 04, 2015 at 09:34:25AM -0500, Steven Rostedt wrote:
> > From: "Steven Rostedt (Red Hat)" <rostedt@goodmis.org>
> >
> > 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
next prev parent reply other threads:[~2015-02-09 15:06 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-04 14:34 [for-next][PATCH 0/7] tracing: Add new filesystem tracefs Steven Rostedt
2015-02-04 14:34 ` [for-next][PATCH 1/7] tracing: Only create tracer options files if directory exists Steven Rostedt
2015-02-04 14:34 ` [for-next][PATCH 2/7] tracing: Create cmdline tracer options on tracing fs init Steven Rostedt
2015-02-04 14:34 ` [for-next][PATCH 3/7] tracefs: Add new tracefs file system Steven Rostedt
2015-02-09 5:56 ` Namhyung Kim
2015-02-09 15:04 ` Steven Rostedt
2015-02-04 14:34 ` [for-next][PATCH 4/7] tracing: Convert the tracing facility over to use tracefs Steven Rostedt
2015-02-04 14:34 ` [for-next][PATCH 5/7] tracing: Automatically mount tracefs on debugfs/tracing Steven Rostedt
2015-02-09 6:00 ` Namhyung Kim
2015-02-09 15:06 ` Steven Rostedt [this message]
2015-02-04 14:34 ` [for-next][PATCH 6/7] tracefs: Add directory /sys/kernel/tracing Steven Rostedt
2015-02-04 14:34 ` [for-next][PATCH 7/7] tracing: Have mkdir and rmdir be part of tracefs Steven Rostedt
2015-02-09 6:07 ` Namhyung Kim
2015-02-09 15:07 ` Steven Rostedt
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