[lttng-dev] [RFC] LTTng-UST loglevels

Mathieu Desnoyers mathieu.desnoyers at efficios.com
Mon Feb 6 18:01:32 EST 2012

From the feedback I got from other lttng developers and users in the
last days, I envision going for loglevels such as:

        TRACE_EMERG     = 0,
        TRACE_ALERT     = 1,
        TRACE_CRIT      = 2,
        TRACE_ERR       = 3,
        TRACE_WARNING   = 4,
        TRACE_NOTICE    = 5,
        TRACE_INFO      = 6,

        TRACE_DEBUG_SYSTEM    = 7,
        TRACE_DEBUG_PROGRAM   = 8,
        TRACE_DEBUG_PROCESS   = 9,
        TRACE_DEBUG_MODULE    = 10,
        TRACE_DEBUG_UNIT      = 11,
        TRACE_DEBUG_LINE      = 13,  (default for TRACEPOINT_EVENT)
        TRACE_DEBUG           = 14,  (default for trace_printf)

The idea is that all the SYSTEM to LINE loglevels are actually sub-parts
of the "debug" loglevel. It seems to make it clearer to keep the "DEBUG"
as part of the names.

I'm not sure about the choices for defaults though. We might want to
keep some room in the numbering for placing loglevels in between
TRACE_DEBUG_LINE and TRACE_DEBUG, as well as below DEBUG. I'm not sure
how to call those. These would be useful if we know for sure that a
tracepoint is higher-throughput that the default TRACEPOINT_LOGLEVEL.
Same reasoning apply to trace_printf.

Thoughts ?



Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.

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