Re: [RFC PATCH] LTTng relay buffer allocation, read, write

Steven Rostedt
2008-09-30T19:44:13Z

On Tue, 30 Sep 2008, Mathieu Desnoyers wrote:
>
> You are actually using them to put redundant information that could be
> encoded differently and thus save 4 bits per event records, more or less
> what will be needed by most tracers (15 IDs, 1 reserved for an extended
> ID field).

I really like the idea of keeping the tracer event ids out of the ring
buffer logic.

>
> So the fact that you use them does not mean they are really required,
> and I don't think such duplicated information actually makes things more
> solid. Maybe just more obscure ?

Well, at least for version 1 these bits stay. I already found two bugs by
hitting the event padding when the size said it should not have. This
redundant information makes me feel a bit more cozy when they match.

-- Steve