/*
*
* Function graph tracer.
* Copyright (c) 2008 Frederic Weisbecker <fweisbec@gmail.com>
* Mostly borrowed from function tracer which
* is Copyright (c) Steven Rostedt <srostedt@redhat.com>
*
*/
#include <linux/debugfs.h>
#include <linux/uaccess.h>
#include <linux/ftrace.h>
#include <linux/fs.h>
#include "trace.h"
#define TRACE_GRAPH_INDENT 2
/* Flag options */
#define TRACE_GRAPH_PRINT_OVERRUN 0x1
#define TRACE_GRAPH_PRINT_CPU 0x2
#define TRACE_GRAPH_PRINT_OVERHEAD 0x4
#define TRACE_GRAPH_PRINT_PROC 0x8
static struct tracer_opt trace_opts[] = {
/* Display overruns ? */
{ TRACER_OPT(funcgraph-overrun, TRACE_GRAPH_PRINT_OVERRUN) },
/* Display CPU ? */
{ TRACER_OPT(funcgraph-cpu, TRACE_GRAPH_PRINT_CPU) },
/* Display Overhead ? */
{ TRACER_OPT(funcgraph-overhead, TRACE_GRAPH_PRINT_OVERHEAD) },
/* Display proc name/pid */
{ TRACER_OPT(funcgraph-proc, TRACE_GRAPH_PRINT_PROC) },
{ } /* Empty entry */
};
static struct tracer_flags tracer_flags = {
/* Don't display overruns and proc by default */
.val = TRACE_GRAPH_PRINT_CPU | TRACE_GRAPH_PRINT_OVERHEAD,
.opts = trace_opts
};
/* pid on the last trace processed */
static pid_t last_pid[NR_CPUS] = { [0 ... NR_CPUS-1] = -1 };
static int graph_trace_init(struct trace_array *tr)
{
int cpu, ret;
for_each_online_cpu(cpu)
tracing_reset(tr, cpu);
ret = register_ftrace_graph(&trace_graph_return,
&trace_graph_entry);
if (ret)
return ret;
tracing_start_cmdline_record();
return 0;
}
static void graph_trace_reset(struct trace_array *tr)
{
tracing_stop_cmdline_record();
unregister_ftrace_graph();
}
static inline int log10_cpu(int nb)
{
if (nb / 100)
return 3;
if (nb / 10)
return 2;
return 1;
}
static enum print_line_t
print_graph_cpu(struct trace_seq *s, int cpu)
{
int i;
int ret;
int log10_this = log10_cpu(cpu);
int log10_all = log10_cpu(cpus_weight_nr(cpu_online_map));
/*
* Start with a space character - to make it stand out
* to the right a bit when trace output is pasted into
* email:
*/
ret = trace_seq_printf(s, " ");
/*
* Tricky - we space the CPU field according to the max
* number of online CPUs. On a 2-cpu system it would take
* a maximum of 1 digit - on a 128 cpu system it would
* take up to 3 digits:
*/
for (i = 0; i < log10_all - log10_this; i++) {
ret = trace_seq_printf(s, " ");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
}
ret = trace_seq_printf(s, "%d) ", cpu);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
return TRACE_TYPE_HANDLED;
}
#define TRACE_GRAPH_PROCINFO_LENGTH 14
static enum print_line_t
print_graph_proc(struct trace_seq *s, pid_t pid)
{
int i;
int ret;
int len;
char comm[8];
int spaces = 0;
/* sign + log10(MAX_INT) + '\0' */
char pid_str[11];
strncpy(comm, trace_find_cmdline(pid), 7);
comm[7] = '\0';
sprintf(pid_str, "%d", pid);