Re: [PATCH -printk] printk, tracing: fix console tracepoint

[John Ogness]

On 2022-05-03, Marco Elver <elver@xxxxxxxxxx> wrote:
> One notable difference is that by moving tracing into printk_sprint(),
> the 'text' will no longer include the "header" (loglevel and timestamp),
> but only the raw message. Arguably this is less of a problem now that
> the console tracepoint happens on the printk() call and isn't delayed.

Another slight difference is that messages composed of LOG_CONT pieces
will trigger the tracepoint for each individual piece and _never_ as a
complete line.

It was never guaranteed that all LOG_CONT pieces make it into the final
printed line anyway, but with this change it will be guaranteed that
they are always handled separately.

I am OK with this change, but like Steven, I agree the the users of that
tracepoint need to chime in.

Acked-by: John Ogness <john.ogness@xxxxxxxxxxxxx>

The ongoing printbuf/seq_buf work [0] will hopefully someday do away
with LOG_CONT altogether.

John

[0] https://lwn.net/Articles/892611