diff options
-rw-r--r-- | Documentation/sysctl/kernel.txt | 8 | ||||
-rw-r--r-- | include/linux/kernel.h | 2 | ||||
-rw-r--r-- | kernel/printk.c | 15 | ||||
-rw-r--r-- | kernel/sysctl.c | 14 |
4 files changed, 39 insertions, 0 deletions
diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt index 3e5b63ebb82..b3d8b492274 100644 --- a/Documentation/sysctl/kernel.txt +++ b/Documentation/sysctl/kernel.txt | |||
@@ -313,6 +313,14 @@ send before ratelimiting kicks in. | |||
313 | 313 | ||
314 | ============================================================== | 314 | ============================================================== |
315 | 315 | ||
316 | printk_delay: | ||
317 | |||
318 | Delay each printk message in printk_delay milliseconds | ||
319 | |||
320 | Value from 0 - 10000 is allowed. | ||
321 | |||
322 | ============================================================== | ||
323 | |||
316 | randomize-va-space: | 324 | randomize-va-space: |
317 | 325 | ||
318 | This option can be used to select the type of process address | 326 | This option can be used to select the type of process address |
diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 2b5b1e0899a..0a2a1908786 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h | |||
@@ -246,6 +246,8 @@ extern int printk_ratelimit(void); | |||
246 | extern bool printk_timed_ratelimit(unsigned long *caller_jiffies, | 246 | extern bool printk_timed_ratelimit(unsigned long *caller_jiffies, |
247 | unsigned int interval_msec); | 247 | unsigned int interval_msec); |
248 | 248 | ||
249 | extern int printk_delay_msec; | ||
250 | |||
249 | /* | 251 | /* |
250 | * Print a one-time message (analogous to WARN_ONCE() et al): | 252 | * Print a one-time message (analogous to WARN_ONCE() et al): |
251 | */ | 253 | */ |
diff --git a/kernel/printk.c b/kernel/printk.c index 932ea21feb1..f38b07f78a4 100644 --- a/kernel/printk.c +++ b/kernel/printk.c | |||
@@ -653,6 +653,20 @@ static int recursion_bug; | |||
653 | static int new_text_line = 1; | 653 | static int new_text_line = 1; |
654 | static char printk_buf[1024]; | 654 | static char printk_buf[1024]; |
655 | 655 | ||
656 | int printk_delay_msec __read_mostly; | ||
657 | |||
658 | static inline void printk_delay(void) | ||
659 | { | ||
660 | if (unlikely(printk_delay_msec)) { | ||
661 | int m = printk_delay_msec; | ||
662 | |||
663 | while (m--) { | ||
664 | mdelay(1); | ||
665 | touch_nmi_watchdog(); | ||
666 | } | ||
667 | } | ||
668 | } | ||
669 | |||
656 | asmlinkage int vprintk(const char *fmt, va_list args) | 670 | asmlinkage int vprintk(const char *fmt, va_list args) |
657 | { | 671 | { |
658 | int printed_len = 0; | 672 | int printed_len = 0; |
@@ -662,6 +676,7 @@ asmlinkage int vprintk(const char *fmt, va_list args) | |||
662 | char *p; | 676 | char *p; |
663 | 677 | ||
664 | boot_delay_msec(); | 678 | boot_delay_msec(); |
679 | printk_delay(); | ||
665 | 680 | ||
666 | preempt_disable(); | 681 | preempt_disable(); |
667 | /* This stops the holder of console_sem just where we want him */ | 682 | /* This stops the holder of console_sem just where we want him */ |
diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 6ba49c7cb12..0dfaa47d7cb 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c | |||
@@ -106,6 +106,9 @@ static int __maybe_unused one = 1; | |||
106 | static int __maybe_unused two = 2; | 106 | static int __maybe_unused two = 2; |
107 | static unsigned long one_ul = 1; | 107 | static unsigned long one_ul = 1; |
108 | static int one_hundred = 100; | 108 | static int one_hundred = 100; |
109 | #ifdef CONFIG_PRINTK | ||
110 | static int ten_thousand = 10000; | ||
111 | #endif | ||
109 | 112 | ||
110 | /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */ | 113 | /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */ |
111 | static unsigned long dirty_bytes_min = 2 * PAGE_SIZE; | 114 | static unsigned long dirty_bytes_min = 2 * PAGE_SIZE; |
@@ -722,6 +725,17 @@ static struct ctl_table kern_table[] = { | |||
722 | .mode = 0644, | 725 | .mode = 0644, |
723 | .proc_handler = &proc_dointvec, | 726 | .proc_handler = &proc_dointvec, |
724 | }, | 727 | }, |
728 | { | ||
729 | .ctl_name = CTL_UNNUMBERED, | ||
730 | .procname = "printk_delay", | ||
731 | .data = &printk_delay_msec, | ||
732 | .maxlen = sizeof(int), | ||
733 | .mode = 0644, | ||
734 | .proc_handler = &proc_dointvec_minmax, | ||
735 | .strategy = &sysctl_intvec, | ||
736 | .extra1 = &zero, | ||
737 | .extra2 = &ten_thousand, | ||
738 | }, | ||
725 | #endif | 739 | #endif |
726 | { | 740 | { |
727 | .ctl_name = KERN_NGROUPS_MAX, | 741 | .ctl_name = KERN_NGROUPS_MAX, |