Messages in this thread | | | Subject | Re: [PATCH] pwm: Add missing '\n' in log messages | From | Joe Perches <> | Date | Tue, 14 Apr 2020 12:04:32 -0700 |
| |
On Tue, 2020-04-14 at 20:30 +0200, Christophe JAILLET wrote: > Being able to detect early missing trailing '\n' would help maintainers > and patch providers. > > You are the 2nd person (I've added Paul Cercueil in copy of my reply) > who reports that he is thinking that it is no more required to add a '\n'.
The printk subsystem will, for every printk, check if the last printk has a newline termination and if it doesn't and the current printk does not start with KERN_CONT will insert a newline.
The negative to this approach is the last printk, if it does not have a newline, is buffered and not emitted until another printk occurs.
There is also the (now small) possibility that multiple concurrent kernel threads or processes could interleave printks without a terminating newline and a different process could emit a printk that starts with KERN_CONT and the emitted message could be garbled.
See:
commit 4bcc595ccd80decb4245096e3d1258989c50ed41 Author: Linus Torvalds <torvalds@linux-foundation.org> Date: Sat Oct 8 20:32:40 2016 -0700
printk: reinstate KERN_CONT for printing continuation lines
| |