tracing: infrastructure for supporting binary record
Impact: save on memory for tracing Current tracers are typically using a struct(like struct ftrace_entry, struct ctx_switch_entry, struct special_entr etc...)to record a binary event. These structs can only record a their own kind of events. A new kind of tracer need a new struct and a lot of code too handle it. So we need a generic binary record for events. This infrastructure is for this purpose. [fweisbec@gmail.com: rebase against latest -tip, make it safe while sched tracing as reported by Steven Rostedt] Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <1236356510-8381-3-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
parent
546e5354a6
commit
1427cdf059
|
@ -223,6 +223,9 @@ extern int ftrace_make_nop(struct module *mod,
|
|||
*/
|
||||
extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr);
|
||||
|
||||
#ifdef CONFIG_TRACE_BPRINTK
|
||||
extern int trace_vbprintk(unsigned long ip, const char *fmt, va_list args);
|
||||
#endif
|
||||
|
||||
/* May be defined in arch */
|
||||
extern int ftrace_arch_read_dyn_info(char *buf, int size);
|
||||
|
|
|
@ -97,6 +97,12 @@ config FUNCTION_GRAPH_TRACER
|
|||
This is done by setting the current return address on the current
|
||||
task structure into a stack of calls.
|
||||
|
||||
config TRACE_BPRINTK
|
||||
bool "Binary printk for tracing"
|
||||
default y
|
||||
depends on TRACING
|
||||
select BINARY_PRINTF
|
||||
|
||||
config IRQSOFF_TRACER
|
||||
bool "Interrupts-off Latency Tracer"
|
||||
default n
|
||||
|
|
|
@ -22,6 +22,7 @@ obj-$(CONFIG_TRACING) += trace.o
|
|||
obj-$(CONFIG_TRACING) += trace_clock.o
|
||||
obj-$(CONFIG_TRACING) += trace_output.o
|
||||
obj-$(CONFIG_TRACING) += trace_stat.o
|
||||
obj-$(CONFIG_TRACE_BPRINTK) += trace_bprintk.o
|
||||
obj-$(CONFIG_CONTEXT_SWITCH_TRACER) += trace_sched_switch.o
|
||||
obj-$(CONFIG_SYSPROF_TRACER) += trace_sysprof.o
|
||||
obj-$(CONFIG_FUNCTION_TRACER) += trace_functions.o
|
||||
|
|
|
@ -3792,6 +3792,62 @@ int __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap)
|
|||
}
|
||||
EXPORT_SYMBOL_GPL(__ftrace_vprintk);
|
||||
|
||||
/**
|
||||
* trace_vbprintk - write binary msg to tracing buffer
|
||||
*
|
||||
* Caller must insure @fmt are valid when msg is in tracing buffer.
|
||||
*/
|
||||
int trace_vbprintk(unsigned long ip, const char *fmt, va_list args)
|
||||
{
|
||||
static DEFINE_SPINLOCK(trace_buf_lock);
|
||||
static u32 trace_buf[TRACE_BUF_SIZE];
|
||||
|
||||
struct ring_buffer_event *event;
|
||||
struct trace_array *tr = &global_trace;
|
||||
struct trace_array_cpu *data;
|
||||
struct bprintk_entry *entry;
|
||||
unsigned long flags;
|
||||
int resched;
|
||||
int cpu, len = 0, size, pc;
|
||||
|
||||
if (tracing_disabled || !trace_bprintk_enable)
|
||||
return 0;
|
||||
|
||||
pc = preempt_count();
|
||||
resched = ftrace_preempt_disable();
|
||||
cpu = raw_smp_processor_id();
|
||||
data = tr->data[cpu];
|
||||
|
||||
if (unlikely(atomic_read(&data->disabled)))
|
||||
goto out;
|
||||
|
||||
spin_lock_irqsave(&trace_buf_lock, flags);
|
||||
len = vbin_printf(trace_buf, TRACE_BUF_SIZE, fmt, args);
|
||||
|
||||
if (len > TRACE_BUF_SIZE || len < 0)
|
||||
goto out_unlock;
|
||||
|
||||
size = sizeof(*entry) + sizeof(u32) * len;
|
||||
event = trace_buffer_lock_reserve(tr, TRACE_BPRINTK, size, flags, pc);
|
||||
if (!event)
|
||||
goto out_unlock;
|
||||
entry = ring_buffer_event_data(event);
|
||||
entry->ip = ip;
|
||||
entry->fmt = fmt;
|
||||
|
||||
memcpy(entry->buf, trace_buf, sizeof(u32) * len);
|
||||
ring_buffer_unlock_commit(tr->buffer, event);
|
||||
|
||||
out_unlock:
|
||||
spin_unlock_irqrestore(&trace_buf_lock, flags);
|
||||
|
||||
out:
|
||||
ftrace_preempt_enable(resched);
|
||||
|
||||
return len;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(trace_vbprintk);
|
||||
|
||||
static int trace_panic_handler(struct notifier_block *this,
|
||||
unsigned long event, void *unused)
|
||||
{
|
||||
|
|
|
@ -20,6 +20,7 @@ enum trace_type {
|
|||
TRACE_WAKE,
|
||||
TRACE_STACK,
|
||||
TRACE_PRINT,
|
||||
TRACE_BPRINTK,
|
||||
TRACE_SPECIAL,
|
||||
TRACE_MMIO_RW,
|
||||
TRACE_MMIO_MAP,
|
||||
|
@ -124,6 +125,16 @@ struct print_entry {
|
|||
char buf[];
|
||||
};
|
||||
|
||||
struct bprintk_entry {
|
||||
struct trace_entry ent;
|
||||
unsigned long ip;
|
||||
const char *fmt;
|
||||
u32 buf[];
|
||||
};
|
||||
#ifdef CONFIG_TRACE_BPRINTK
|
||||
extern int trace_bprintk_enable;
|
||||
#endif
|
||||
|
||||
#define TRACE_OLD_SIZE 88
|
||||
|
||||
struct trace_field_cont {
|
||||
|
@ -285,6 +296,7 @@ extern void __ftrace_bad_type(void);
|
|||
IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK); \
|
||||
IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
|
||||
IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT); \
|
||||
IF_ASSIGN(var, ent, struct bprintk_entry, TRACE_BPRINTK);\
|
||||
IF_ASSIGN(var, ent, struct special_entry, 0); \
|
||||
IF_ASSIGN(var, ent, struct trace_mmiotrace_rw, \
|
||||
TRACE_MMIO_RW); \
|
||||
|
|
87
kernel/trace/trace_bprintk.c
Normal file
87
kernel/trace/trace_bprintk.c
Normal file
|
@ -0,0 +1,87 @@
|
|||
/*
|
||||
* trace binary printk
|
||||
*
|
||||
* Copyright (C) 2008 Lai Jiangshan <laijs@cn.fujitsu.com>
|
||||
*
|
||||
*/
|
||||
#include <linux/kernel.h>
|
||||
#include <linux/ftrace.h>
|
||||
#include <linux/string.h>
|
||||
#include <linux/ctype.h>
|
||||
#include <linux/list.h>
|
||||
#include <linux/mutex.h>
|
||||
#include <linux/slab.h>
|
||||
#include <linux/module.h>
|
||||
#include <linux/seq_file.h>
|
||||
#include <linux/fs.h>
|
||||
#include <linux/marker.h>
|
||||
#include <linux/uaccess.h>
|
||||
|
||||
#include "trace.h"
|
||||
|
||||
/* binary printk basic */
|
||||
static DEFINE_MUTEX(btrace_mutex);
|
||||
static int btrace_metadata_count;
|
||||
|
||||
static inline void lock_btrace(void)
|
||||
{
|
||||
mutex_lock(&btrace_mutex);
|
||||
}
|
||||
|
||||
static inline void unlock_btrace(void)
|
||||
{
|
||||
mutex_unlock(&btrace_mutex);
|
||||
}
|
||||
|
||||
static void get_btrace_metadata(void)
|
||||
{
|
||||
lock_btrace();
|
||||
btrace_metadata_count++;
|
||||
unlock_btrace();
|
||||
}
|
||||
|
||||
static void put_btrace_metadata(void)
|
||||
{
|
||||
lock_btrace();
|
||||
btrace_metadata_count--;
|
||||
unlock_btrace();
|
||||
}
|
||||
|
||||
/* events tracer */
|
||||
int trace_bprintk_enable;
|
||||
|
||||
static void start_bprintk_trace(struct trace_array *tr)
|
||||
{
|
||||
get_btrace_metadata();
|
||||
tracing_reset_online_cpus(tr);
|
||||
trace_bprintk_enable = 1;
|
||||
}
|
||||
|
||||
static void stop_bprintk_trace(struct trace_array *tr)
|
||||
{
|
||||
trace_bprintk_enable = 0;
|
||||
tracing_reset_online_cpus(tr);
|
||||
put_btrace_metadata();
|
||||
}
|
||||
|
||||
static int init_bprintk_trace(struct trace_array *tr)
|
||||
{
|
||||
start_bprintk_trace(tr);
|
||||
return 0;
|
||||
}
|
||||
|
||||
static struct tracer bprintk_trace __read_mostly =
|
||||
{
|
||||
.name = "events",
|
||||
.init = init_bprintk_trace,
|
||||
.reset = stop_bprintk_trace,
|
||||
.start = start_bprintk_trace,
|
||||
.stop = stop_bprintk_trace,
|
||||
};
|
||||
|
||||
static __init int init_bprintk(void)
|
||||
{
|
||||
return register_tracer(&bprintk_trace);
|
||||
}
|
||||
|
||||
device_initcall(init_bprintk);
|
|
@ -53,6 +53,26 @@ trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
|
|||
return len;
|
||||
}
|
||||
|
||||
static int
|
||||
trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary)
|
||||
{
|
||||
int len = (PAGE_SIZE - 1) - s->len;
|
||||
int ret;
|
||||
|
||||
if (!len)
|
||||
return 0;
|
||||
|
||||
ret = bstr_printf(s->buffer + s->len, len, fmt, binary);
|
||||
|
||||
/* If we can't write it all, don't bother writing anything */
|
||||
if (ret >= len)
|
||||
return 0;
|
||||
|
||||
s->len += ret;
|
||||
|
||||
return len;
|
||||
}
|
||||
|
||||
/**
|
||||
* trace_seq_puts - trace sequence printing of simple string
|
||||
* @s: trace sequence descriptor
|
||||
|
@ -855,6 +875,60 @@ static struct trace_event trace_print_event = {
|
|||
.raw = trace_print_raw,
|
||||
};
|
||||
|
||||
/* TRACE_BPRINTK */
|
||||
static enum print_line_t
|
||||
trace_bprintk_print(struct trace_iterator *iter, int flags)
|
||||
{
|
||||
struct trace_entry *entry = iter->ent;
|
||||
struct trace_seq *s = &iter->seq;
|
||||
struct bprintk_entry *field;
|
||||
|
||||
trace_assign_type(field, entry);
|
||||
|
||||
if (!seq_print_ip_sym(s, field->ip, flags))
|
||||
goto partial;
|
||||
|
||||
if (!trace_seq_puts(s, ": "))
|
||||
goto partial;
|
||||
|
||||
if (!trace_seq_bprintf(s, field->fmt, field->buf))
|
||||
goto partial;
|
||||
|
||||
return TRACE_TYPE_HANDLED;
|
||||
|
||||
partial:
|
||||
return TRACE_TYPE_PARTIAL_LINE;
|
||||
}
|
||||
|
||||
static enum print_line_t
|
||||
trace_bprintk_raw(struct trace_iterator *iter, int flags)
|
||||
{
|
||||
struct trace_entry *entry = iter->ent;
|
||||
struct trace_seq *s = &iter->seq;
|
||||
struct bprintk_entry *field;
|
||||
|
||||
trace_assign_type(field, entry);
|
||||
|
||||
if (!trace_seq_printf(s, ": %lx : ", field->ip))
|
||||
goto partial;
|
||||
|
||||
if (!trace_seq_bprintf(s, field->fmt, field->buf))
|
||||
goto partial;
|
||||
|
||||
return TRACE_TYPE_HANDLED;
|
||||
|
||||
partial:
|
||||
return TRACE_TYPE_PARTIAL_LINE;
|
||||
}
|
||||
|
||||
static struct trace_event trace_bprintk_event = {
|
||||
.type = TRACE_BPRINTK,
|
||||
.trace = trace_bprintk_print,
|
||||
.raw = trace_bprintk_raw,
|
||||
.hex = trace_nop_print,
|
||||
.binary = trace_nop_print,
|
||||
};
|
||||
|
||||
static struct trace_event *events[] __initdata = {
|
||||
&trace_fn_event,
|
||||
&trace_ctx_event,
|
||||
|
@ -863,6 +937,7 @@ static struct trace_event *events[] __initdata = {
|
|||
&trace_stack_event,
|
||||
&trace_user_stack_event,
|
||||
&trace_print_event,
|
||||
&trace_bprintk_event,
|
||||
NULL
|
||||
};
|
||||
|
||||
|
|
Loading…
Reference in a new issue