From 769b0441f438c4bb4872cb8560eb6fe51bcc09ee Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Fri, 6 Mar 2009 17:21:49 +0100 Subject: tracing/core: drop the old trace_printk() implementation in favour of trace_bprintk() 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 Acked-by: Steven Rostedt LKML-Reference: <1236356510-8381-5-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar --- include/linux/kernel.h | 34 +++++++++++++++++++++++++++++++--- 1 file changed, 31 insertions(+), 3 deletions(-) (limited to 'include/linux/kernel.h') diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 7aef15c4645e..4e726b9a71ec 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -423,6 +423,16 @@ extern void ftrace_off_permanent(void); extern void ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3); +static inline void __attribute__ ((format (printf, 1, 2))) +____trace_printk_check_format(const char *fmt, ...) +{ +} +#define __trace_printk_check_format(fmt, args...) \ +do { \ + if (0) \ + ____trace_printk_check_format(fmt, ##args); \ +} while (0) + /** * trace_printk - printf formatting in the ftrace buffer * @fmt: the printf format for printing @@ -439,13 +449,31 @@ ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3); * Please refrain from leaving trace_printks scattered around in * your code. */ -# define trace_printk(fmt...) __trace_printk(_THIS_IP_, fmt) + +#define trace_printk(fmt, args...) \ +do { \ + static const char *trace_printk_fmt \ + __attribute__((section("__trace_printk_fmt"))); \ + trace_printk_fmt = fmt; \ + __trace_printk_check_format(fmt, ##args); \ + __trace_printk(_THIS_IP_, trace_printk_fmt, ##args); \ +} while (0) + extern int __trace_printk(unsigned long ip, const char *fmt, ...) __attribute__ ((format (printf, 2, 3))); -# define ftrace_vprintk(fmt, ap) __trace_printk(_THIS_IP_, fmt, ap) + +#define ftrace_vprintk(fmt, vargs) \ +do { \ + static const char *trace_printk_fmt \ + __attribute__((section("__trace_printk_fmt"))); \ + trace_printk_fmt = fmt; \ + __ftrace_vprintk(_THIS_IP_, trace_printk_fmt, vargs); \ +} while (0) + extern int __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap); + extern void ftrace_dump(void); #else static inline void @@ -467,7 +495,7 @@ ftrace_vprintk(const char *fmt, va_list ap) return 0; } static inline void ftrace_dump(void) { } -#endif +#endif /* CONFIG_TRACING */ /* * Display an IP address in readable format. -- cgit v1.2.3-71-gd317