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

From: Steven Rostedt
Date: Tue Jul 12 2022 - 10:54:15 EST

On Tue, 12 Jul 2022 06:49:16 -0700
"Paul E. McKenney" <paulmck@xxxxxxxxxx> wrote:

> > I guess the question is, can we have printk() in such a place? Because this
> > tracepoint is attached to printk and where ever printk is done so is this
> > tracepoint.
> As I understand it, code in such a place should be labeled noinstr.
> Then the call to printk() would be complained about as an illegal
> noinstr-to-non-noinstr call.
> But where exactly is that printk()?

Perhaps the fix is to remove the _rcuidle() from trace_console_rcuidle().
If printk() can never be called from noinstr (aka RCU not watching).

-- Steve