In nvprof, start/end timestamps were given in ns from epoch. Looking at the sqlite files exported from qdrep, it seems that timestamps are now relative to some profiling start moment. This way, events from different profiling sessions cannot be correlated externally.
It would be helpful to have the absolute timestamp of the reference time stored in the database (or return to absolute timestamps).
As a temporary bypass, I’m emitting a special marker with the timestamp at profiling start and later calculate the origin absolute timestamp as (T-t), where T is the absolute timestamp and t is the relative timestamp when it was emitted.