[PATCH] tracing/function-return-tracer: change the name into function-graph-tracer

From: Frederic Weisbecker
Date: Tue Nov 25 2008 - 15:07:27 EST

Impact: cleanups

This patch changes the name of the return function tracer into
function-graph-tracer which is a more suitable name for a tracing
which makes one able to retrieve the ordered call stack during
the code flow.

Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
---
arch/x86/Kconfig | 2 +-
arch/x86/include/asm/ftrace.h | 4 +-
arch/x86/kernel/Makefile | 4 +-
arch/x86/kernel/entry_32.S | 12 ++--
arch/x86/kernel/ftrace.c | 12 ++--
include/linux/ftrace.h | 24 ++++----
include/linux/ftrace_irq.h | 2 +-
include/linux/sched.h | 2 +-
kernel/Makefile | 2 +-
kernel/fork.c | 4 +-
kernel/sched.c | 2 +-
kernel/trace/Kconfig | 19 ++++---
kernel/trace/Makefile | 2 +-
kernel/trace/ftrace.c | 26 +++++-----
kernel/trace/trace.c | 18 +++---
kernel/trace/trace.h | 12 ++--
kernel/trace/trace_functions_graph.c | 98 ++++++++++++++++++++++++++++++++++
17 files changed, 173 insertions(+), 72 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index f10d40b..e7c0a1b 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -29,7 +29,7 @@ config X86
select HAVE_FTRACE_MCOUNT_RECORD
select HAVE_DYNAMIC_FTRACE
select HAVE_FUNCTION_TRACER
- select HAVE_FUNCTION_RET_TRACER if X86_32
+ select HAVE_FUNCTION_GRAPH_TRACER if X86_32
select HAVE_FUNCTION_TRACE_MCOUNT_TEST
select HAVE_KVM if ((X86_32 && !X86_VOYAGER && !X86_VISWS && !X86_NUMAQ) || X86_64)
select HAVE_ARCH_KGDB if !X86_VOYAGER
diff --git a/arch/x86/include/asm/ftrace.h b/arch/x86/include/asm/ftrace.h
index 754a3e0..7e61b4c 100644
--- a/arch/x86/include/asm/ftrace.h
+++ b/arch/x86/include/asm/ftrace.h
@@ -28,7 +28,7 @@ struct dyn_arch_ftrace {
#endif /* __ASSEMBLY__ */
#endif /* CONFIG_FUNCTION_TRACER */

-#ifdef CONFIG_FUNCTION_RET_TRACER
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER

#ifndef __ASSEMBLY__

@@ -51,6 +51,6 @@ struct ftrace_ret_stack {
extern void return_to_handler(void);

#endif /* __ASSEMBLY__ */
-#endif /* CONFIG_FUNCTION_RET_TRACER */
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */

#endif /* _ASM_X86_FTRACE_H */
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 01272a4..6074f7c 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -15,7 +15,7 @@ CFLAGS_REMOVE_ftrace.o = -pg
CFLAGS_REMOVE_early_printk.o = -pg
endif

-ifdef CONFIG_FUNCTION_RET_TRACER
+ifdef CONFIG_FUNCTION_GRAPH_TRACER
# Don't trace __switch_to() but let it for function tracer
CFLAGS_REMOVE_process_32.o = -pg
endif
@@ -72,7 +72,7 @@ obj-$(CONFIG_X86_LOCAL_APIC) += apic.o nmi.o
obj-$(CONFIG_X86_IO_APIC) += io_apic.o
obj-$(CONFIG_X86_REBOOTFIXUPS) += reboot_fixups_32.o
obj-$(CONFIG_DYNAMIC_FTRACE) += ftrace.o
-obj-$(CONFIG_FUNCTION_RET_TRACER) += ftrace.o
+obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += ftrace.o
obj-$(CONFIG_KEXEC) += machine_kexec_$(BITS).o
obj-$(CONFIG_KEXEC) += relocate_kernel_$(BITS).o crash.o
obj-$(CONFIG_CRASH_DUMP) += crash_dump_$(BITS).o
diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index 7a934c0..dbe8488 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -1199,9 +1199,9 @@ ENTRY(mcount)

cmpl $ftrace_stub, ftrace_trace_function
jnz trace
-#ifdef CONFIG_FUNCTION_RET_TRACER
- cmpl $ftrace_stub, ftrace_function_return
- jnz ftrace_return_caller
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ cmpl $ftrace_stub, ftrace_graph_function
+ jnz ftrace_graph_caller
#endif
.globl ftrace_stub
ftrace_stub:
@@ -1226,8 +1226,8 @@ END(mcount)
#endif /* CONFIG_DYNAMIC_FTRACE */
#endif /* CONFIG_FUNCTION_TRACER */

-#ifdef CONFIG_FUNCTION_RET_TRACER
-ENTRY(ftrace_return_caller)
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ENTRY(ftrace_graph_caller)
cmpl $0, function_trace_stop
jne ftrace_stub

@@ -1241,7 +1241,7 @@ ENTRY(ftrace_return_caller)
popl %ecx
popl %eax
ret
-END(ftrace_return_caller)
+END(ftrace_graph_caller)

.globl return_to_handler
return_to_handler:
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index bb137f7..3595a4c 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -323,7 +323,7 @@ int __init ftrace_dyn_arch_init(void *data)
}
#endif

-#ifdef CONFIG_FUNCTION_RET_TRACER
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER

#ifndef CONFIG_DYNAMIC_FTRACE

@@ -389,11 +389,11 @@ static void pop_return_trace(unsigned long *ret, unsigned long long *time,
*/
unsigned long ftrace_return_to_handler(void)
{
- struct ftrace_retfunc trace;
+ struct ftrace_graph_ret trace;
pop_return_trace(&trace.ret, &trace.calltime, &trace.func,
&trace.overrun);
trace.rettime = cpu_clock(raw_smp_processor_id());
- ftrace_function_return(&trace);
+ ftrace_graph_function(&trace);

return trace.ret;
}
@@ -440,12 +440,12 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
);

if (WARN_ON(faulted)) {
- unregister_ftrace_return();
+ unregister_ftrace_graph();
return;
}

if (WARN_ON(!__kernel_text_address(old))) {
- unregister_ftrace_return();
+ unregister_ftrace_graph();
*parent = old;
return;
}
@@ -456,4 +456,4 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
*parent = old;
}

-#endif /* CONFIG_FUNCTION_RET_TRACER */
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 7854d87..b4ac734 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -115,8 +115,8 @@ extern int ftrace_update_ftrace_func(ftrace_func_t func);
extern void ftrace_caller(void);
extern void ftrace_call(void);
extern void mcount_call(void);
-#ifdef CONFIG_FUNCTION_RET_TRACER
-extern void ftrace_return_caller(void);
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+extern void ftrace_graph_caller(void);
#endif

/**
@@ -315,7 +315,7 @@ ftrace_init_module(struct module *mod,
/*
* Structure that defines a return function trace.
*/
-struct ftrace_retfunc {
+struct ftrace_graph_ret {
unsigned long ret; /* Return address */
unsigned long func; /* Current function */
unsigned long long calltime;
@@ -324,22 +324,22 @@ struct ftrace_retfunc {
unsigned long overrun;
};

-#ifdef CONFIG_FUNCTION_RET_TRACER
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
#define FTRACE_RETFUNC_DEPTH 50
#define FTRACE_RETSTACK_ALLOC_SIZE 32
/* Type of a callback handler of tracing return function */
-typedef void (*trace_function_return_t)(struct ftrace_retfunc *);
+typedef void (*trace_function_graph_t)(struct ftrace_graph_ret *);

-extern int register_ftrace_return(trace_function_return_t func);
+extern int register_ftrace_graph(trace_function_graph_t func);
/* The current handler in use */
-extern trace_function_return_t ftrace_function_return;
-extern void unregister_ftrace_return(void);
+extern trace_function_graph_t ftrace_graph_function;
+extern void unregister_ftrace_graph(void);

-extern void ftrace_retfunc_init_task(struct task_struct *t);
-extern void ftrace_retfunc_exit_task(struct task_struct *t);
+extern void ftrace_graph_init_task(struct task_struct *t);
+extern void ftrace_graph_exit_task(struct task_struct *t);
#else
-static inline void ftrace_retfunc_init_task(struct task_struct *t) { }
-static inline void ftrace_retfunc_exit_task(struct task_struct *t) { }
+static inline void ftrace_graph_init_task(struct task_struct *t) { }
+static inline void ftrace_graph_exit_task(struct task_struct *t) { }
#endif

#endif /* _LINUX_FTRACE_H */
diff --git a/include/linux/ftrace_irq.h b/include/linux/ftrace_irq.h
index 0b4df55..366a054 100644
--- a/include/linux/ftrace_irq.h
+++ b/include/linux/ftrace_irq.h
@@ -2,7 +2,7 @@
#define _LINUX_FTRACE_IRQ_H


-#if defined(CONFIG_DYNAMIC_FTRACE) || defined(CONFIG_FUNCTION_RET_TRACER)
+#if defined(CONFIG_DYNAMIC_FTRACE) || defined(CONFIG_FUNCTION_GRAPH_TRACER)
extern void ftrace_nmi_enter(void);
extern void ftrace_nmi_exit(void);
#else
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 3f80f40..a572392 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1362,7 +1362,7 @@ struct task_struct {
unsigned long default_timer_slack_ns;

struct list_head *scm_work_list;
-#ifdef CONFIG_FUNCTION_RET_TRACER
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
/* Index of current stored adress in ret_stack */
int curr_ret_stack;
/* Stack of return addresses for return function tracing */
diff --git a/kernel/Makefile b/kernel/Makefile
index 010ccb3..86e2d82 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -20,7 +20,7 @@ CFLAGS_REMOVE_rtmutex-debug.o = -pg
CFLAGS_REMOVE_cgroup-debug.o = -pg
CFLAGS_REMOVE_sched_clock.o = -pg
endif
-ifdef CONFIG_FUNCTION_RET_TRACER
+ifdef CONFIG_FUNCTION_GRAPH_TRACER
CFLAGS_REMOVE_extable.o = -pg # For __kernel_text_address()
CFLAGS_REMOVE_module.o = -pg # For __module_text_address()
endif
diff --git a/kernel/fork.c b/kernel/fork.c
index d183739..afb376d 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -141,7 +141,7 @@ void free_task(struct task_struct *tsk)
prop_local_destroy_single(&tsk->dirties);
free_thread_info(tsk->stack);
rt_mutex_debug_task_free(tsk);
- ftrace_retfunc_exit_task(tsk);
+ ftrace_graph_exit_task(tsk);
free_task_struct(tsk);
}
EXPORT_SYMBOL(free_task);
@@ -1276,7 +1276,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
total_forks++;
spin_unlock(&current->sighand->siglock);
write_unlock_irq(&tasklist_lock);
- ftrace_retfunc_init_task(p);
+ ftrace_graph_init_task(p);
proc_fork_connector(p);
cgroup_post_fork(p);
return p;
diff --git a/kernel/sched.c b/kernel/sched.c
index 60fa98a..6ff2667 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -5864,7 +5864,7 @@ void __cpuinit init_idle(struct task_struct *idle, int cpu)
* The idle tasks have their own, simple scheduling class:
*/
idle->sched_class = &idle_sched_class;
- ftrace_retfunc_init_task(idle);
+ ftrace_graph_init_task(idle);
}

/*
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 620fead..eb9b901 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -12,7 +12,7 @@ config NOP_TRACER
config HAVE_FUNCTION_TRACER
bool

-config HAVE_FUNCTION_RET_TRACER
+config HAVE_FUNCTION_GRAPH_TRACER
bool

config HAVE_FUNCTION_TRACE_MCOUNT_TEST
@@ -63,15 +63,18 @@ config FUNCTION_TRACER
(the bootup default), then the overhead of the instructions is very
small and not measurable even in micro-benchmarks.

-config FUNCTION_RET_TRACER
- bool "Kernel Function return Tracer"
- depends on HAVE_FUNCTION_RET_TRACER
+config FUNCTION_GRAPH_TRACER
+ bool "Kernel Function Graph Tracer"
+ depends on HAVE_FUNCTION_GRAPH_TRACER
depends on FUNCTION_TRACER
help
- Enable the kernel to trace a function at its return.
- It's first purpose is to trace the duration of functions.
- This is done by setting the current return address on the thread
- info structure of the current task.
+ Enable the kernel to trace a function at both its return
+ and its entry.
+ It's first purpose is to trace the duration of functions and
+ draw a call graph for each thread with some informations like
+ the return value.
+ This is done by setting the current return address on the current
+ task structure into a stack of calls.

config IRQSOFF_TRACER
bool "Interrupts-off Latency Tracer"
diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile
index cef4bcb..08c5fe6 100644
--- a/kernel/trace/Makefile
+++ b/kernel/trace/Makefile
@@ -29,7 +29,7 @@ obj-$(CONFIG_NOP_TRACER) += trace_nop.o
obj-$(CONFIG_STACK_TRACER) += trace_stack.o
obj-$(CONFIG_MMIOTRACE) += trace_mmiotrace.o
obj-$(CONFIG_BOOT_TRACER) += trace_boot.o
-obj-$(CONFIG_FUNCTION_RET_TRACER) += trace_functions_return.o
+obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += trace_functions_graph.o
obj-$(CONFIG_TRACE_BRANCH_PROFILING) += trace_branch.o
obj-$(CONFIG_BTS_TRACER) += trace_bts.o

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 53042f1..9e19976 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -395,11 +395,11 @@ __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
unsigned long ip, fl;
unsigned long ftrace_addr;

-#ifdef CONFIG_FUNCTION_RET_TRACER
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
if (ftrace_tracing_type == FTRACE_TYPE_ENTER)
ftrace_addr = (unsigned long)ftrace_caller;
else
- ftrace_addr = (unsigned long)ftrace_return_caller;
+ ftrace_addr = (unsigned long)ftrace_graph_caller;
#else
ftrace_addr = (unsigned long)ftrace_caller;
#endif
@@ -1496,13 +1496,13 @@ ftrace_enable_sysctl(struct ctl_table *table, int write,
return ret;
}

-#ifdef CONFIG_FUNCTION_RET_TRACER
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER

static atomic_t ftrace_retfunc_active;

/* The callback that hooks the return of a function */
-trace_function_return_t ftrace_function_return =
- (trace_function_return_t)ftrace_stub;
+trace_function_graph_t ftrace_graph_function =
+ (trace_function_graph_t)ftrace_stub;


/* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
@@ -1549,7 +1549,7 @@ free:
}

/* Allocate a return stack for each task */
-static int start_return_tracing(void)
+static int start_graph_tracing(void)
{
struct ftrace_ret_stack **ret_stack_list;
int ret;
@@ -1569,7 +1569,7 @@ static int start_return_tracing(void)
return ret;
}

-int register_ftrace_return(trace_function_return_t func)
+int register_ftrace_graph(trace_function_graph_t func)
{
int ret = 0;

@@ -1584,13 +1584,13 @@ int register_ftrace_return(trace_function_return_t func)
goto out;
}
atomic_inc(&ftrace_retfunc_active);
- ret = start_return_tracing();
+ ret = start_graph_tracing();
if (ret) {
atomic_dec(&ftrace_retfunc_active);
goto out;
}
ftrace_tracing_type = FTRACE_TYPE_RETURN;
- ftrace_function_return = func;
+ ftrace_graph_function = func;
ftrace_startup();

out:
@@ -1598,12 +1598,12 @@ out:
return ret;
}

-void unregister_ftrace_return(void)
+void unregister_ftrace_graph(void)
{
mutex_lock(&ftrace_sysctl_lock);

atomic_dec(&ftrace_retfunc_active);
- ftrace_function_return = (trace_function_return_t)ftrace_stub;
+ ftrace_graph_function = (trace_function_graph_t)ftrace_stub;
ftrace_shutdown();
/* Restore normal tracing type */
ftrace_tracing_type = FTRACE_TYPE_ENTER;
@@ -1612,7 +1612,7 @@ void unregister_ftrace_return(void)
}

/* Allocate a return stack for newly created task */
-void ftrace_retfunc_init_task(struct task_struct *t)
+void ftrace_graph_init_task(struct task_struct *t)
{
if (atomic_read(&ftrace_retfunc_active)) {
t->ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
@@ -1626,7 +1626,7 @@ void ftrace_retfunc_init_task(struct task_struct *t)
t->ret_stack = NULL;
}

-void ftrace_retfunc_exit_task(struct task_struct *t)
+void ftrace_graph_exit_task(struct task_struct *t)
{
struct ftrace_ret_stack *ret_stack = t->ret_stack;

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 8df8fdd..f21ab2c 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -878,15 +878,15 @@ trace_function(struct trace_array *tr, struct trace_array_cpu *data,
ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
}

-#ifdef CONFIG_FUNCTION_RET_TRACER
-static void __trace_function_return(struct trace_array *tr,
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+static void __trace_function_graph(struct trace_array *tr,
struct trace_array_cpu *data,
- struct ftrace_retfunc *trace,
+ struct ftrace_graph_ret *trace,
unsigned long flags,
int pc)
{
struct ring_buffer_event *event;
- struct ftrace_ret_entry *entry;
+ struct ftrace_graph_entry *entry;
unsigned long irq_flags;

if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled))))
@@ -1177,8 +1177,8 @@ function_trace_call(unsigned long ip, unsigned long parent_ip)
local_irq_restore(flags);
}

-#ifdef CONFIG_FUNCTION_RET_TRACER
-void trace_function_return(struct ftrace_retfunc *trace)
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+void trace_function_graph(struct ftrace_graph_ret *trace)
{
struct trace_array *tr = &global_trace;
struct trace_array_cpu *data;
@@ -1193,12 +1193,12 @@ void trace_function_return(struct ftrace_retfunc *trace)
disabled = atomic_inc_return(&data->disabled);
if (likely(disabled == 1)) {
pc = preempt_count();
- __trace_function_return(tr, data, trace, flags, pc);
+ __trace_function_graph(tr, data, trace, flags, pc);
}
atomic_dec(&data->disabled);
raw_local_irq_restore(flags);
}
-#endif /* CONFIG_FUNCTION_RET_TRACER */
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */

static struct ftrace_ops trace_ops __read_mostly =
{
@@ -2001,7 +2001,7 @@ static enum print_line_t print_trace_fmt(struct trace_iterator *iter)
break;
}
case TRACE_FN_RET: {
- return print_return_function(iter);
+ return print_graph_function(iter);
break;
}
case TRACE_BRANCH: {
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 3abd645..72b5ef8 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -57,7 +57,7 @@ struct ftrace_entry {
};

/* Function return entry */
-struct ftrace_ret_entry {
+struct ftrace_graph_entry {
struct trace_entry ent;
unsigned long ip;
unsigned long parent_ip;
@@ -264,7 +264,7 @@ extern void __ftrace_bad_type(void);
IF_ASSIGN(var, ent, struct trace_boot_call, TRACE_BOOT_CALL);\
IF_ASSIGN(var, ent, struct trace_boot_ret, TRACE_BOOT_RET);\
IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
- IF_ASSIGN(var, ent, struct ftrace_ret_entry, TRACE_FN_RET);\
+ IF_ASSIGN(var, ent, struct ftrace_graph_entry, TRACE_FN_RET);\
IF_ASSIGN(var, ent, struct bts_entry, TRACE_BTS);\
__ftrace_bad_type(); \
} while (0)
@@ -398,7 +398,7 @@ void trace_function(struct trace_array *tr,
unsigned long parent_ip,
unsigned long flags, int pc);
void
-trace_function_return(struct ftrace_retfunc *trace);
+trace_function_graph(struct ftrace_graph_ret *trace);

void trace_bts(struct trace_array *tr,
unsigned long from,
@@ -489,11 +489,11 @@ extern int trace_vprintk(unsigned long ip, const char *fmt, va_list args);
extern unsigned long trace_flags;

/* Standard output formatting function used for function return traces */
-#ifdef CONFIG_FUNCTION_RET_TRACER
-extern enum print_line_t print_return_function(struct trace_iterator *iter);
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+extern enum print_line_t print_graph_function(struct trace_iterator *iter);
#else
static inline enum print_line_t
-print_return_function(struct trace_iterator *iter)
+print_graph_function(struct trace_iterator *iter)
{
return TRACE_TYPE_UNHANDLED;
}
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
new file mode 100644
index 0000000..f5bad46
--- /dev/null
+++ b/kernel/trace/trace_functions_graph.c
@@ -0,0 +1,98 @@
+/*
+ *
+ * Function graph tracer.
+ * Copyright (c) 2008 Frederic Weisbecker <fweisbec@xxxxxxxxx>
+ * Mostly borrowed from function tracer which
+ * is Copyright (c) Steven Rostedt <srostedt@xxxxxxxxxx>
+ *
+ */
+#include <linux/debugfs.h>
+#include <linux/uaccess.h>
+#include <linux/ftrace.h>
+#include <linux/fs.h>
+
+#include "trace.h"
+
+
+#define TRACE_GRAPH_PRINT_OVERRUN 0x1
+static struct tracer_opt trace_opts[] = {
+ /* Display overruns or not */
+ { TRACER_OPT(overrun, TRACE_GRAPH_PRINT_OVERRUN) },
+ { } /* Empty entry */
+};
+
+static struct tracer_flags tracer_flags = {
+ .val = 0, /* Don't display overruns by default */
+ .opts = trace_opts
+};
+
+
+static int graph_trace_init(struct trace_array *tr)
+{
+ int cpu;
+ for_each_online_cpu(cpu)
+ tracing_reset(tr, cpu);
+
+ return register_ftrace_graph(&trace_function_graph);
+}
+
+static void graph_trace_reset(struct trace_array *tr)
+{
+ unregister_ftrace_graph();
+}
+
+
+enum print_line_t
+print_graph_function(struct trace_iterator *iter)
+{
+ struct trace_seq *s = &iter->seq;
+ struct trace_entry *entry = iter->ent;
+ struct ftrace_graph_entry *field;
+ int ret;
+
+ if (entry->type == TRACE_FN_RET) {
+ trace_assign_type(field, entry);
+ ret = trace_seq_printf(s, "%pF -> ", (void *)field->parent_ip);
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+
+ ret = seq_print_ip_sym(s, field->ip,
+ trace_flags & TRACE_ITER_SYM_MASK);
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+
+ ret = trace_seq_printf(s, " (%llu ns)",
+ field->rettime - field->calltime);
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+
+ if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERRUN) {
+ ret = trace_seq_printf(s, " (Overruns: %lu)",
+ field->overrun);
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+ }
+
+ ret = trace_seq_printf(s, "\n");
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+
+ return TRACE_TYPE_HANDLED;
+ }
+ return TRACE_TYPE_UNHANDLED;
+}
+
+static struct tracer graph_trace __read_mostly = {
+ .name = "function-graph",
+ .init = graph_trace_init,
+ .reset = graph_trace_reset,
+ .print_line = print_graph_function,
+ .flags = &tracer_flags,
+};
+
+static __init int init_graph_trace(void)
+{
+ return register_tracer(&graph_trace);
+}
+
+device_initcall(init_graph_trace);
--
1.5.2.5
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