79 строки
1.6 KiB
C
79 строки
1.6 KiB
C
/*
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* ring buffer based function tracer
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*
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* Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
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* Copyright (C) 2008 Ingo Molnar <mingo@redhat.com>
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*
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* Based on code from the latency_tracer, that is:
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*
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* Copyright (C) 2004-2006 Ingo Molnar
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* Copyright (C) 2004 William Lee Irwin III
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*/
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#include <linux/debugfs.h>
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#include <linux/uaccess.h>
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#include <linux/ftrace.h>
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#include <linux/fs.h>
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#include "trace.h"
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static void function_reset(struct trace_array *tr)
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{
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int cpu;
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tr->time_start = ftrace_now(tr->cpu);
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for_each_online_cpu(cpu)
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tracing_reset(tr->data[cpu]);
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}
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static void start_function_trace(struct trace_array *tr)
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{
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function_reset(tr);
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atomic_inc(&trace_record_cmdline_enabled);
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tracing_start_function_trace();
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}
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static void stop_function_trace(struct trace_array *tr)
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{
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tracing_stop_function_trace();
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atomic_dec(&trace_record_cmdline_enabled);
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}
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static void function_trace_init(struct trace_array *tr)
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{
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if (tr->ctrl)
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start_function_trace(tr);
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}
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static void function_trace_reset(struct trace_array *tr)
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{
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if (tr->ctrl)
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stop_function_trace(tr);
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}
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static void function_trace_ctrl_update(struct trace_array *tr)
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{
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if (tr->ctrl)
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start_function_trace(tr);
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else
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stop_function_trace(tr);
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}
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static struct tracer function_trace __read_mostly =
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{
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.name = "ftrace",
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.init = function_trace_init,
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.reset = function_trace_reset,
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.ctrl_update = function_trace_ctrl_update,
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#ifdef CONFIG_FTRACE_SELFTEST
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.selftest = trace_selftest_startup_function,
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#endif
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};
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static __init int init_function_trace(void)
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{
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return register_tracer(&function_trace);
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}
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device_initcall(init_function_trace);
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