Messages in this thread | | | Date | Mon, 9 Feb 2015 10:06:26 -0500 | From | Steven Rostedt <> | Subject | Re: [for-next][PATCH 5/7] tracing: Automatically mount tracefs on debugfs/tracing |
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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
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