Re: [tracing] ring_buffer question

From: Steven Rostedt
Date: Mon May 18 2009 - 13:03:15 EST



On Mon, 18 May 2009, David Smith wrote:

> Steven Rostedt wrote:
> > On Mon, 18 May 2009, David Smith wrote:
> >
> >> Jon Masters wrote:
> >>> [thinking out loud] Does the global disable stuff also disable other
> >>> non-tracing ring buffers?
> >> I believe it does. If I'm correct, I think it would be a good idea to
> >> make that an ftrace-disable feature, not a general ring buffer disable
> >> feature.
> >
> > We can do that when we get more users of the ring buffer and we find it
> > makes sense.
>
> It appears that oprofile is already using the ring buffer. With Jon's
> stuff as a 2nd non-ftrace-user, doesn't it make sense now?

I guess it might also be something that we want to consider too. That is,
the "tracing_off" is a nice feature for all users of the ring buffer. Once
can stop and start the oprofiler buffer via the user interface
"tracing_on" as well. Is this something that would also be useful? If we
make it "ftrace only" then oprofile loses this feature.

Now we could make a file for every registered user of the ring buffer.
Well, not every registered user, but have the user register their own
"tracing_on" file.

-- Steve

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