[ltt-dev] Multi-second gaps in trace events

Mathieu Desnoyers compudj at krystal.dyndns.org
Wed Sep 30 13:29:33 EDT 2009

* Chad Willman (cwillman at lifesize.com) wrote:
> I¹m seeing long (multi-second) gaps in trace events and am wondering if this
> is a known issue.
> For example, trace events shown in the viewer appear normal and then
> suddenly there will be a gap of 9 seconds (varies) where it appears that a
> single thread is running in user mode (green) and nothing else is happening
> on the entire system in any thread for 9 seconds (no context switches, . . .
> nothing).
> This is an excellent tracing facility, but I can¹t rely on it entirely until
> I have no gaps in the trace. Any ideas ?
> I¹m running -
> Lttng v 0.6.33 on Linux 2.6.18 kernel on a TI DaVinci DM6467T SOC platform

That's an ARM board right ?

On these boards, LTTng has a 1 jiffy precision, because it uses the
"generic clock". Within this interval, events are simply counted, e.g. 1
cycle = 1 event.

The ARM OMAP3 has cycle counters, which LTTng uses.


> Ltt-control v 0.30
> Lttv v 0.8.72
> Genevent v 0.30
> Regards,
> CW

> _______________________________________________
> ltt-dev mailing list
> ltt-dev at lists.casi.polymtl.ca
> http://lists.casi.polymtl.ca/cgi-bin/mailman/listinfo/ltt-dev

Mathieu Desnoyers
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F  BA06 3F25 A8FE 3BAE 9A68

More information about the lttng-dev mailing list