[ltt-dev] LTTng specialized probes

[mbligh@google.com (Martin Bligh)]

> <core event header, aligned on 32 bits>
> 1-bit opt. ext. TSC (active if a 27-bits TSC overflow is detected)
> 27-bits TSC
> 4-bits event ID (ID #7 reserved to specify (optional) extended event ID,
>                 ID #6 reserved to specify both ext. event ID and event
>                 size)

That's pretty much exactly what ktrace had. You don't need to reserve
a bit for the TSC overflow, that can be an event, which gives you
31 events instead of 16 ?

However, the problem with this is you're no longer separating the
ringbuffer layer (and timing) from the event tracing layer, or at
least not on a byte boundary.