155 lines
3.4 KiB
C
155 lines
3.4 KiB
C
/*
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*
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* Function graph tracer.
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* Copyright (c) 2008 Frederic Weisbecker <fweisbec@gmail.com>
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* Mostly borrowed from function tracer which
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* is Copyright (c) Steven Rostedt <srostedt@redhat.com>
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*
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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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#define TRACE_GRAPH_INDENT 2
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#define TRACE_GRAPH_PRINT_OVERRUN 0x1
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static struct tracer_opt trace_opts[] = {
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/* Display overruns or not */
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{ TRACER_OPT(overrun, TRACE_GRAPH_PRINT_OVERRUN) },
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{ } /* Empty entry */
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};
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static struct tracer_flags tracer_flags = {
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.val = 0, /* Don't display overruns by default */
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.opts = trace_opts
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};
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/* pid on the last trace processed */
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static pid_t last_pid = -1;
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static int graph_trace_init(struct trace_array *tr)
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{
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int cpu;
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for_each_online_cpu(cpu)
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tracing_reset(tr, cpu);
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return register_ftrace_graph(&trace_graph_return,
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&trace_graph_entry);
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}
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static void graph_trace_reset(struct trace_array *tr)
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{
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unregister_ftrace_graph();
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}
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/* If the pid changed since the last trace, output this event */
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static int verif_pid(struct trace_seq *s, pid_t pid)
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{
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if (last_pid != -1 && last_pid == pid)
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return 1;
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last_pid = pid;
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return trace_seq_printf(s, "\n------------8<---------- thread %d"
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" ------------8<----------\n\n",
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pid);
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}
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static enum print_line_t
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print_graph_entry(struct ftrace_graph_ent *call, struct trace_seq *s,
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struct trace_entry *ent)
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{
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int i;
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int ret;
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if (!verif_pid(s, ent->pid))
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return TRACE_TYPE_PARTIAL_LINE;
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for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
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ret = trace_seq_printf(s, " ");
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if (!ret)
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return TRACE_TYPE_PARTIAL_LINE;
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}
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ret = seq_print_ip_sym(s, call->func, 0);
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if (!ret)
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return TRACE_TYPE_PARTIAL_LINE;
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ret = trace_seq_printf(s, "() {\n");
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if (!ret)
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return TRACE_TYPE_PARTIAL_LINE;
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return TRACE_TYPE_HANDLED;
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}
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static enum print_line_t
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print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
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struct trace_entry *ent)
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{
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int i;
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int ret;
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if (!verif_pid(s, ent->pid))
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return TRACE_TYPE_PARTIAL_LINE;
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for (i = 0; i < trace->depth * TRACE_GRAPH_INDENT; i++) {
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ret = trace_seq_printf(s, " ");
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if (!ret)
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return TRACE_TYPE_PARTIAL_LINE;
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}
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ret = trace_seq_printf(s, "} ");
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if (!ret)
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return TRACE_TYPE_PARTIAL_LINE;
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ret = trace_seq_printf(s, "%llu\n", trace->rettime - trace->calltime);
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if (!ret)
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return TRACE_TYPE_PARTIAL_LINE;
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if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERRUN) {
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ret = trace_seq_printf(s, " (Overruns: %lu)\n",
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trace->overrun);
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if (!ret)
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return TRACE_TYPE_PARTIAL_LINE;
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}
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return TRACE_TYPE_HANDLED;
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}
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enum print_line_t
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print_graph_function(struct trace_iterator *iter)
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{
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struct trace_seq *s = &iter->seq;
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struct trace_entry *entry = iter->ent;
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switch (entry->type) {
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case TRACE_GRAPH_ENT: {
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struct ftrace_graph_ent_entry *field;
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trace_assign_type(field, entry);
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return print_graph_entry(&field->graph_ent, s, entry);
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}
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case TRACE_GRAPH_RET: {
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struct ftrace_graph_ret_entry *field;
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trace_assign_type(field, entry);
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return print_graph_return(&field->ret, s, entry);
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}
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default:
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return TRACE_TYPE_UNHANDLED;
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}
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}
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static struct tracer graph_trace __read_mostly = {
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.name = "function-graph",
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.init = graph_trace_init,
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.reset = graph_trace_reset,
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.print_line = print_graph_function,
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.flags = &tracer_flags,
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};
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static __init int init_graph_trace(void)
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{
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return register_tracer(&graph_trace);
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}
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device_initcall(init_graph_trace);
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