From: Randy Dunlap Add "notime" boot option to prevent timing data from being printed on each printk message line. We've seen a few cases of 'time' data locking problems (possibly involving netconsole or net drivers). If a kernel is built with CONFIG_PRINTK_TIME=y, it may have a boot locking hang. Booting with "notime" may (i.e., could) prevent the lock hang and allow the kernel to boot successfully, without requiring a kernel rebuild. Signed-off-by: Randy Dunlap Signed-off-by: Andrew Morton --- Documentation/kernel-parameters.txt | 2 ++ kernel/printk.c | 10 +++++++++- 2 files changed, 11 insertions(+), 1 deletion(-) diff -puN Documentation/kernel-parameters.txt~add-notime-boot-option Documentation/kernel-parameters.txt --- a/Documentation/kernel-parameters.txt~add-notime-boot-option +++ a/Documentation/kernel-parameters.txt @@ -1237,6 +1237,8 @@ and is between 256 and 4096 characters. nosync [HW,M68K] Disables sync negotiation for all devices. + notime Do not print timing data on each printk message line. + notsc [BUGS=X86-32] Disable Time Stamp Counter nousb [USB] Disable the USB subsystem diff -puN kernel/printk.c~add-notime-boot-option kernel/printk.c --- a/kernel/printk.c~add-notime-boot-option +++ a/kernel/printk.c @@ -458,9 +458,17 @@ static int __init printk_time_setup(char printk_time = 1; return 1; } - __setup("time", printk_time_setup); +static int __init printk_notime_setup(char *str) +{ + if (*str) + return 0; + printk_time = 0; + return 1; +} +__setup("notime", printk_notime_setup); + __attribute__((weak)) unsigned long long printk_clock(void) { return sched_clock(); _