[ltt-dev] LTTng and Timestamps mismatch

[abhikaro@gmail.com (Abhishek Karoliya)]

Hello People,

I am using LTTng to get around a scheduling and priority inheritance
problem that we are observing on our system (powerpc e500v2 dual core,
linux 2.6.34). However, I need map timestamps for events as seen in
Lttng trace, kernel and application (I am using TSC divided by time
base freq for application). I see that even though stop tracing
(lttctl -D ) at 601.xxxxxx (/var/log/kernel )
Nov 21 16:26:13 XRX9C93E4059FFD kernel: [ ?601.695548] LTT: 284 events
written in channel metadata (cpu 1, index 0)
Nov 21 16:26:13 XRX9C93E4059FFD kernel: [ ?601.710868] LTT: 40 events
written in channel module_state (cpu 1, index 0)
...............................................
Nov 21 16:26:13 XRX9C93E4059FFD kernel: [ ?601.710978] LTT: 32 events
written in channel softirq_state (cpu 1, index 0)

When I look dump the trace using lttv, I can see events that are
timestamped upto 670.xxxxxxxx.

I am wondering if this is due some timing offset? If yes, how could I
match them?

My Setup
ltt-control-0.89-05122011
lttv-0.12.36-18112010
linux-2.6.32 with pre-empt RT patch

Any pointers will be greatly appreciated.

Thanks
Abhi