Re: [PATCH] printk: add KERN_NOTIME to skip the timestamp

From: Sergey Senozhatsky
Date: Wed Feb 13 2019 - 01:29:20 EST


On (02/13/19 14:19), xiang xiao wrote:
> Here is my case:
> 1.A small MCU(Cortex M4) in SoC run RTOS
> 2.RTOS append timestamp to log for the accurate timing
> 3.RTOS send log to Linux kernel when buffer exceed the threshold
> 4.Kernel call printk to dump the received buffer
> So I want that printk skip the timestamp here.
>
> > If anything, I would probably prefer that we export whether
> > time is being printed, and have the caller not print time if printk is
> > doing it already, than to add the complexity into printk itself.
>
> Actually, the timestamp of our initial implementation like your
> suggestion come from printk,

cat /sys/module/printk/parameters/time ?

Y - we add time prefix
N - we don't add time prefix

-ss