[lttng-dev] LTTng event loglevel

[Alexandre Montplaisir]

Hi,

On 2015-06-22 05:06 PM, Jeffrey Chen wrote:
> Hi:
>
> I am reading the LTTng and I am confused about the loglevel in the document. The document talked about it could assign a loglevel to each event. (http://lttng.org/docs/#doc-assigning-log-levels)

This part refers to when you define your own tracepoints in your pogram, 
using the TRACEPOINT_EVENT macro.

>   But, later in the document, it says all events from LTTng are traced as loglevel TRACE_DEBUG_FUNCTION. (http://lttng.org/docs/#doc-liblttng%E2%80%91ust%E2%80%91cyg%E2%80%91profile)

That part however, refers to using the liblttng-ust-cyg-profile library, 
to automatically instrument function entries and exits. This library 
implements the callbacks expected by cyg-profile, and puts the 
information into UST tracepoints. Since it's this 
liblttng-ust-cyg-profile library that "defines" the tracepoints here, 
they are stuck at the log level specified in their definition, which is 
TRACE_DEBUG_FUNCTION in this case.


Hope this helps,
Alexandre