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tracing/core: drop the old trace_printk() implementation in favour of trace_bprintk()

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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>
This commit is contained in:
Frederic Weisbecker 2009-03-06 17:21:49 +01:00 • committed by Ingo Molnar
commit 769b0441f4
12 changed files with 164 additions and 315 deletions
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25
include/linux/ftrace.h
View file

@ -223,31 +223,6 @@ 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);
extern int __trace_bprintk(unsigned long ip, const char *fmt, ...)
__attribute__ ((format (printf, 2, 3)));
static inline void ____trace_bprintk_check_format(const char *fmt, ...)
__attribute__ ((format (printf, 1, 2)));
static inline void ____trace_bprintk_check_format(const char *fmt, ...) {}
#define __trace_bprintk_check_format(fmt, args...) \
do { \
if (0) \
____trace_bprintk_check_format(fmt, ##args); \
} while (0)
#define trace_bprintk(fmt, args...) \
do { \
static char *__attribute__((section("__trace_bprintk_fmt"))) \
trace_bprintk_fmt = fmt; \
__trace_bprintk_check_format(fmt, ##args); \
__trace_bprintk(_THIS_IP_, trace_bprintk_fmt, ##args); \
} while (0)
#else
#define trace_bprintk trace_printk
#endif
/* May be defined in arch */
extern int ftrace_arch_read_dyn_info(char *buf, int size);