On 07/25/2017 09:00 AM, Peter Zijlstra wrote: > On Tue, Jul 25, 2017 at 08:17:27AM -0400, Prarit Bhargava wrote: >> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug >> index 5b1662ec546f..6cd38a25f8ea 100644 >> --- a/lib/Kconfig.debug >> +++ b/lib/Kconfig.debug >> @@ -1,8 +1,8 @@ >> menu "printk and dmesg options" >> >> config PRINTK_TIME >> - int "Show timing information on printks (0-1)" >> - range 0 1 >> + int "Show timing information on printks (0-3)" >> + range 0 3 >> default "0" >> depends on PRINTK >> help >> @@ -13,7 +13,8 @@ config PRINTK_TIME >> The timestamp is always recorded internally, and exported >> to /dev/kmsg. This flag just specifies if the timestamp should >> be included, not that the timestamp is recorded. 0 disables the >> - timestamp and 1 uses the local clock. >> + timestamp and 1 uses the local clock, 2 uses the monotonic clock, and >> + 3 uses real clock. >> >> The behavior is also controlled by the kernel command line >> parameter printk.time=1. See >> Documentation/admin-guide/kernel-parameters.rst > > > choice > prompt "printk default clock" > default PRIMTK_TIME_DISABLE > help > goes here > > config PRINTK_TIME_DISABLE > bool "Disabled" > help > goes here > > config PRINTK_TIME_LOCAL > bool "local clock" > help > goes here > > config PRINTK_TIME_MONO > bool "CLOCK_MONOTONIC" > help > goes here > > config PRINTK_TIME_REAL > bool "CLOCK_REALTIME" > help > goes here > > endchoice > > config PRINTK_TIME > int > default 0 if PRINTK_TIME_DISABLE > default 1 if PRINTK_TIME_LOCAL > default 2 if PRINTK_TIME_MONO > default 3 if PRINTK_TIME_REAL > >
Thanks for the above change. I can see that makes the code simpler. > Although I must strongly discourage using REALTIME, DST will make > untangling your logs an absolute nightmare. I would simply not provide > it. I understand your concern, however, I've been in situations where REALTIME stamping has pointed me in the direction of where a bug was. Even with the complicated logs I think it is worthwhile. P.
