Virtualization - Jun 2022 - [PATCH 24/36] printk: Remove trace_.*_rcuidle() usage

On Thu 2022-06-09 20:30:58, Sergey Senozhatsky wrote:
> My emails are getting rejected... Let me try web-interface
Bad day for mail sending. I have problems as well ;-)
> Kudos to Petr for the questions and thanks to PeterZ for the answers.
> 
> On Thu, Jun 9, 2022 at 7:02 PM Peter Zijlstra <peterz at
infradead.org> wrote:
> > This is the tracepoint used to spool all of printk into ftrace, I
> > suspect there's users, but I haven't used it myself.
> 
> I'm somewhat curious whether we can actually remove that trace event.
Good question.

Well, I think that it might be useful. It allows to see trace and
printk messages together.

It was ugly when it was in the console code. The new location
in vprintk_store() allows to have it even "correctly" sorted
(timestamp) against other tracing messages.

Best Regards,
Petr

On Thu, 9 Jun 2022 15:02:20 +0200
Petr Mladek <pmladek at suse.com> wrote:
> > I'm somewhat curious whether we can actually remove that trace
event.
> 
> Good question.
> 
> Well, I think that it might be useful. It allows to see trace and
> printk messages together.
Yes people still use it. I was just asked about it at Kernel Recipes. That
is, someone wanted printk mixed in with the tracing, and I told them about
this event (which they didn't know about but was happy to hear that it
existed).

-- Steve