Built-In Probe Point Types (Dwarf Probes) - Red Hat ENTERPRISE LINUX 5.4 - SYSTEMTAP LANGUAGE Reference Manual

Chapter 4. Probe points
The following is the general syntax.
kernel.function("no_such_function") ?

4.2. Built-in probe point types (DWARF probes)

This family of probe points uses symbolic debugging information for the target kernel or module, as
may be found in executables that have not been stripped, or in the separate debuginfo packages.
They allow logical placement of probes into the execution path of the target by specifying a set of
points in the source or object code. When a matching statement executes on any processor, the probe
handler is run in that context.
Points in a kernel are identified by module, source file, line number, function name or some
combination of these.
Here is a list of probe point specifications currently supported:
kernel.function(PATTERN)
kernel.function(PATTERN).call
kernel.function(PATTERN).return
kernel.function(PATTERN).return.maxactive(VALUE)
kernel.function(PATTERN).inline
kernel.function(PATTERN).label(LPATTERN)
module(MPATTERN).function(PATTERN)
module(MPATTERN).function(PATTERN).call
module(MPATTERN).function(PATTERN).return.maxactive(VALUE)
module(MPATTERN).function(PATTERN).inline
kernel.statement(PATTERN)
kernel.statement(ADDRESS).absolute
module(MPATTERN).statement(PATTERN)
The .function variant places a probe near the beginning of the named function, so that parameters
are available as context variables.
The .return variant places a probe at the moment of return from the named function, so the return
value is available as the $return context variable. The entry parameters are also available, though the
function may have changed their values. Return probes may be further qualified with .maxactive,
which specifies how many instances of the specified function can be probed simultaneously. You can
leave off .maxactive in most cases, as the default should be sufficient. However, if you notice an
excessive number of skipped probes, try setting .maxactive to incrementally higher values to see if
the number of skipped probes decreases.
The .inline modifier for .function filters the results to include only instances of inlined functions.
The .call modifier selects the opposite subset. Inline functions do not have an identifiable return
point, so .return is not supported on .inline probes.
The .statement variant places a probe at the exact spot, exposing those local variables that are
visible there.
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