[Ksummit-discuss] [TECH TOPIC] printk redesign

[Al Viro]

On Sat, Jun 24, 2017 at 04:26:42PM -0700, Linus Torvalds wrote:
> On Sat, Jun 24, 2017 at 4:21 PM, Andrew Lunn <andrew at lunn.ch> wrote:
> > This assumes timestamps are fine grained enough. I still prefer a
> > sequence number in addition.
> 
> Guyes, you're overdesigning.
> 
> The general old printk subsystem had "continuations". Nobody ever used
> them. Nobody. I know, because they were broken, and nobody even
> reported it.
> 
> Similarly, nobody is going to use sequence numbers and timestamps.
> What *is* going to get used is digital cameras to take pictures of a
> screen, and "dmesg" output (and no, dmesg will not use those sequence
> numbers either, see above).

I'd really hate to have to use pictures of screen...  I really hope that
printk to serial console keeps working - I don't care about timestamps
granularity, etc., but losing this would hurt.  Is it really that
uncommon use case?