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

From: Steven Rostedt
Date: Tue Jul 12 2022 - 09:39:53 EST

On Tue, 12 Jul 2022 04:49:54 -0700
"Paul E. McKenney" <paulmck@xxxxxxxxxx> wrote:

> > But a quick fix that stopped the bleeding and allowed printk() to
> > progress would be useful in the short term, regardless of whether or
> > not in the longer term it makes sense to make srcu_read_lock_trace()
> > and srcu_read_unlock_trace() NMI-safe.
> Except that doesn't rcuidle && in_nmi() imply a misplaced trace event?
> Isn't it still the case that you are not supposed to have trace events
> in NMI handlers before RCU is watching or after it is no longer watching,
> just as for entry/exit code in general? Once in the body of the handler,
> rcuidle should be false and all should be well.
> Or am I missing something here?

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

-- Steve