History

[PATCH] clean up kernel messages

Arrange for all kernel printks to be no-ops. Only available if CONFIG_EMBEDDED. This patch saves about 375k on my laptop config and nearly 100k on minimal configs.

Matt Mackall committed 21 years ago

Commit d59745c1 parent cd7619d4 files · +43 −6Browse files

Unified · Split

4 files
  1. arch/i386/kernel/head.S +2 −0
  2. include/linux/kernel.h +9 −0
  3. init/Kconfig +11 −0
  4. kernel/printk.c +21 −6
arch/i386/kernel/head.S+2−0
@@ -380,6 +380,7 @@ rp_sidt: · 379 unmodified lines
380 ALIGN380 ALIGN
381ignore_int:381ignore_int:
382 cld382 cld
383#ifdef CONFIG_PRINTK
383 pushl %eax384 pushl %eax
384 pushl %ecx385 pushl %ecx
385 pushl %edx386 pushl %edx
@@ -400,6 +401,7 @@ ignore_int: · 14 unmodified lines
400 popl %edx401 popl %edx
401 popl %ecx402 popl %ecx
402 popl %eax403 popl %eax
404#endif
403 iret405 iret
404 406
405/*407/*
include/linux/kernel.h+9−0
@@ -115,10 +115,19 @@ extern int __kernel_text_address(unsigned long addr); · 114 unmodified lines
115extern int kernel_text_address(unsigned long addr);115extern int kernel_text_address(unsigned long addr);
116extern int session_of_pgrp(int pgrp);116extern int session_of_pgrp(int pgrp);
117 117
118#ifdef CONFIG_PRINTK
118asmlinkage int vprintk(const char *fmt, va_list args)119asmlinkage int vprintk(const char *fmt, va_list args)
119 __attribute__ ((format (printf, 1, 0)));120 __attribute__ ((format (printf, 1, 0)));
120asmlinkage int printk(const char * fmt, ...)121asmlinkage int printk(const char * fmt, ...)
121 __attribute__ ((format (printf, 1, 2)));122 __attribute__ ((format (printf, 1, 2)));
123#else
124static inline int vprintk(const char *s, va_list args)
125 __attribute__ ((format (printf, 1, 0)));
126static inline int vprintk(const char *s, va_list args) { return 0; }
127static inline int printk(const char *s, ...)
128 __attribute__ ((format (printf, 1, 2)));
129static inline int printk(const char *s, ...) { return 0; }
130#endif
122 131
123unsigned long int_sqrt(unsigned long);132unsigned long int_sqrt(unsigned long);
124 133
init/Kconfig+11−0
@@ -275,6 +275,17 @@ config KALLSYMS_EXTRA_PASS · 274 unmodified lines
275 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while275 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
276 you wait for kallsyms to be fixed.276 you wait for kallsyms to be fixed.
277 277
278
279config PRINTK
280 default y
281 bool "Enable support for printk" if EMBEDDED
282 help
283 This option enables normal printk support. Removing it
284 eliminates most of the message strings from the kernel image
285 and makes the kernel more or less silent. As this makes it
286 very difficult to diagnose system problems, saying N here is
287 strongly discouraged.
288
278config BUG289config BUG
279 bool "BUG() support" if EMBEDDED290 bool "BUG() support" if EMBEDDED
280 default y291 default y
kernel/printk.c+21−6
@@ -85,10 +85,6 @@ static int console_locked; · 84 unmodified lines
85 */85 */
86static DEFINE_SPINLOCK(logbuf_lock);86static DEFINE_SPINLOCK(logbuf_lock);
87 87
88static char __log_buf[__LOG_BUF_LEN];
89static char *log_buf = __log_buf;
90static int log_buf_len = __LOG_BUF_LEN;
91
92#define LOG_BUF_MASK (log_buf_len-1)88#define LOG_BUF_MASK (log_buf_len-1)
93#define LOG_BUF(idx) (log_buf[(idx) & LOG_BUF_MASK])89#define LOG_BUF(idx) (log_buf[(idx) & LOG_BUF_MASK])
94 90
@@ -99,7 +95,6 @@ static int log_buf_len = __LOG_BUF_LEN; · 4 unmodified lines
99static unsigned long log_start; /* Index into log_buf: next char to be read by syslog() */95static unsigned long log_start; /* Index into log_buf: next char to be read by syslog() */
100static unsigned long con_start; /* Index into log_buf: next char to be sent to consoles */96static unsigned long con_start; /* Index into log_buf: next char to be sent to consoles */
101static unsigned long log_end; /* Index into log_buf: most-recently-written-char + 1 */97static unsigned long log_end; /* Index into log_buf: most-recently-written-char + 1 */
102static unsigned long logged_chars; /* Number of chars produced since last read+clear operation */
103 98
104/*99/*
105 * Array of consoles built from command line options (console=)100 * Array of consoles built from command line options (console=)
@@ -120,6 +115,13 @@ static int preferred_console = -1; · 14 unmodified lines
120/* Flag: console code may call schedule() */115/* Flag: console code may call schedule() */
121static int console_may_schedule;116static int console_may_schedule;
122 117
118#ifdef CONFIG_PRINTK
119
120static char __log_buf[__LOG_BUF_LEN];
121static char *log_buf = __log_buf;
122static int log_buf_len = __LOG_BUF_LEN;
123static unsigned long logged_chars; /* Number of chars produced since last read+clear operation */
124
123/*125/*
124 * Setup a list of consoles. Called from init/main.c126 * Setup a list of consoles. Called from init/main.c
125 */127 */
@@ -535,6 +537,7 @@ __setup("time", printk_time_setup); · 409 unmodified lines
535 * then changes console_loglevel may break. This is because console_loglevel537 * then changes console_loglevel may break. This is because console_loglevel
536 * is inspected when the actual printing occurs.538 * is inspected when the actual printing occurs.
537 */539 */
540
538asmlinkage int printk(const char *fmt, ...)541asmlinkage int printk(const char *fmt, ...)
539{542{
540 va_list args;543 va_list args;
@@ -655,6 +658,18 @@ out: · 114 unmodified lines
655EXPORT_SYMBOL(printk);658EXPORT_SYMBOL(printk);
656EXPORT_SYMBOL(vprintk);659EXPORT_SYMBOL(vprintk);
657 660
661#else
662
663asmlinkage long sys_syslog(int type, char __user * buf, int len)
664{
665 return 0;
666}
667
668int do_syslog(int type, char __user * buf, int len) { return 0; }
669static void call_console_drivers(unsigned long start, unsigned long end) {}
670
671#endif
672
658/**673/**
659 * acquire_console_sem - lock the console system for exclusive use.674 * acquire_console_sem - lock the console system for exclusive use.
660 *675 *
@@ -931,7 +946,7 @@ int unregister_console(struct console * console) · 270 unmodified lines
931 return res;946 return res;
932}947}
933EXPORT_SYMBOL(unregister_console);948EXPORT_SYMBOL(unregister_console);
934 949
935/**950/**
936 * tty_write_message - write a message to a certain tty, not just the console.951 * tty_write_message - write a message to a certain tty, not just the console.
937 *952 *