Every perf script Python script should start by setting up a
Python module search path and 'import'ing a few support modules
(see module descriptions below):
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import os
import sys
sys.path.append(os.environ['PERF_EXEC_PATH'] + \
'/scripts/python/Perf-Trace-Util/lib/Perf/Trace')
from perf_trace_context import *
from Core import *
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The rest of the script can contain handler functions and support
functions in any order.
Aside from the event handler functions discussed above, every
script can implement a set of optional functions:
trace_begin, if defined, is called before any event is processed
and gives scripts a chance to do setup tasks:
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def trace_begin():
pass
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trace_end, if defined, is called after all events have been
processed and gives scripts a chance to do end-of-script tasks,
such as display results:
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def trace_end():
pass
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trace_unhandled, if defined, is called after for any event that
doesn't have a handler explicitly defined for it. The standard
set of common arguments are passed into it:
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def trace_unhandled(event_name, context, event_fields_dict):
pass
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process_event, if defined, is called for any non-tracepoint event
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def process_event(param_dict):
pass
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context_switch, if defined, is called for any context switch
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def context_switch(ts, cpu, pid, tid, np_pid, np_tid, machine_pid, out, out_preempt, *x):
pass
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auxtrace_error, if defined, is called for any AUX area tracing
error
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def auxtrace_error(typ, code, cpu, pid, tid, ip, ts, msg, cpumode, *x):
pass
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The remaining sections provide descriptions of each of the
available built-in perf script Python modules and their
associated functions.
