[lttng-dev] clarification on limiting the size of the trace file

Thibault, Daniel Daniel.Thibault at drdc-rddc.gc.ca
Thu May 8 09:40:15 EDT 2014

-----Message d'origine-----
Envoyé : 8 mai 2014 07:26

> Thanks, I upgraded and this problem was fixed. 
> But I noticed something new.
> When I run the "lttng list command" I get the events in different order from two locations I installed the new version.
> Did you encounter such an issue before?
> Mirit 

   I'm not sure I understand your question or your concern.  Do you mean that the output of 'lttng list -k' is different each time it is run, or different between otherwise-identical machines?  Or are you talking about 'lttng list -u'?  Or 'lttng list <session_name>'?

   LTTng makes no guarantees that the list of events is sorted in any particular way.  Kernel events normally appear in last-module-loaded-first order, with the events within a module appearing in seemingly arbitrary order (probably last-declared-first within each module).  The ordering of user-space events is truly unpredictable, as it depends on the order in which tracepoint providers register with the session daemon.

   If you need strict ordering of the event listing, you must do it yourself (in a programmatic context) or pipe it through the 'sort' applet (in a shell script context).

Daniel U. Thibault
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