mirror of
https://github.com/adulau/aha.git
synced 2024-12-28 03:36:19 +00:00
769b0441f4
Impact: faster and lighter tracing Now that we have trace_bprintk() which is faster and consume lesser memory than trace_printk() and has the same purpose, we can now drop the old implementation in favour of the binary one from trace_bprintk(), which means we move all the implementation of trace_bprintk() to trace_printk(), so the Api doesn't change except that we must now use trace_seq_bprintk() to print the TRACE_PRINT entries. Some changes result of this: - Previously, trace_bprintk depended of a single tracer and couldn't work without. This tracer has been dropped and the whole implementation of trace_printk() (like the module formats management) is now integrated in the tracing core (comes with CONFIG_TRACING), though we keep the file trace_printk (previously trace_bprintk.c) where we can find the module management. Thus we don't overflow trace.c - changes some parts to use trace_seq_bprintk() to print TRACE_PRINT entries. - change a bit trace_printk/trace_vprintk macros to support non-builtin formats constants, and fix 'const' qualifiers warnings. But this is all transparent for developers. - etc... V2: - Rebase against last changes - Fix mispell on the changelog V3: - Rebase against last changes (moving trace_printk() to kernel.h) Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <1236356510-8381-5-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
138 lines
3 KiB
C
138 lines
3 KiB
C
/*
|
|
* 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"
|
|
|
|
#ifdef CONFIG_MODULES
|
|
|
|
/*
|
|
* modules trace_printk()'s formats are autosaved in struct trace_bprintk_fmt
|
|
* which are queued on trace_bprintk_fmt_list.
|
|
*/
|
|
static LIST_HEAD(trace_bprintk_fmt_list);
|
|
|
|
/* serialize accesses to trace_bprintk_fmt_list */
|
|
static DEFINE_MUTEX(btrace_mutex);
|
|
|
|
struct trace_bprintk_fmt {
|
|
struct list_head list;
|
|
char fmt[0];
|
|
};
|
|
|
|
static inline struct trace_bprintk_fmt *lookup_format(const char *fmt)
|
|
{
|
|
struct trace_bprintk_fmt *pos;
|
|
list_for_each_entry(pos, &trace_bprintk_fmt_list, list) {
|
|
if (!strcmp(pos->fmt, fmt))
|
|
return pos;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
static
|
|
void hold_module_trace_bprintk_format(const char **start, const char **end)
|
|
{
|
|
const char **iter;
|
|
|
|
mutex_lock(&btrace_mutex);
|
|
for (iter = start; iter < end; iter++) {
|
|
struct trace_bprintk_fmt *tb_fmt = lookup_format(*iter);
|
|
if (tb_fmt) {
|
|
*iter = tb_fmt->fmt;
|
|
continue;
|
|
}
|
|
|
|
tb_fmt = kmalloc(offsetof(struct trace_bprintk_fmt, fmt)
|
|
+ strlen(*iter) + 1, GFP_KERNEL);
|
|
if (tb_fmt) {
|
|
list_add_tail(&tb_fmt->list, &trace_bprintk_fmt_list);
|
|
strcpy(tb_fmt->fmt, *iter);
|
|
*iter = tb_fmt->fmt;
|
|
} else
|
|
*iter = NULL;
|
|
}
|
|
mutex_unlock(&btrace_mutex);
|
|
}
|
|
|
|
static int module_trace_bprintk_format_notify(struct notifier_block *self,
|
|
unsigned long val, void *data)
|
|
{
|
|
struct module *mod = data;
|
|
if (mod->num_trace_bprintk_fmt) {
|
|
const char **start = mod->trace_bprintk_fmt_start;
|
|
const char **end = start + mod->num_trace_bprintk_fmt;
|
|
|
|
if (val == MODULE_STATE_COMING)
|
|
hold_module_trace_bprintk_format(start, end);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
#else /* !CONFIG_MODULES */
|
|
__init static int
|
|
module_trace_bprintk_format_notify(struct notifier_block *self,
|
|
unsigned long val, void *data)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif /* CONFIG_MODULES */
|
|
|
|
|
|
__initdata_or_module static
|
|
struct notifier_block module_trace_bprintk_format_nb = {
|
|
.notifier_call = module_trace_bprintk_format_notify,
|
|
};
|
|
|
|
int __trace_printk(unsigned long ip, const char *fmt, ...)
|
|
{
|
|
int ret;
|
|
va_list ap;
|
|
|
|
if (unlikely(!fmt))
|
|
return 0;
|
|
|
|
if (!(trace_flags & TRACE_ITER_PRINTK))
|
|
return 0;
|
|
|
|
va_start(ap, fmt);
|
|
ret = trace_vprintk(ip, task_curr_ret_stack(current), fmt, ap);
|
|
va_end(ap);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(__trace_printk);
|
|
|
|
int __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap)
|
|
{
|
|
if (unlikely(!fmt))
|
|
return 0;
|
|
|
|
if (!(trace_flags & TRACE_ITER_PRINTK))
|
|
return 0;
|
|
|
|
return trace_vprintk(ip, task_curr_ret_stack(current), fmt, ap);
|
|
}
|
|
EXPORT_SYMBOL_GPL(__ftrace_vprintk);
|
|
|
|
|
|
static __init int init_trace_printk(void)
|
|
{
|
|
return register_module_notifier(&module_trace_bprintk_format_nb);
|
|
}
|
|
|
|
early_initcall(init_trace_printk);
|