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Date: Thu, 16 Feb 2017 13:25:00 +0900
From: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To: Tony Lindgren <tony@atomide.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
        Petr Mladek <pmladek@suse.com>, Steven Rostedt <rostedt@goodmis.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Thomas Gleixner <tglx@linutronix.de>, linux-kernel@vger.kernel.org,
        "Rafael J. Wysocki" <rjw@rjwysocki.net>, linux-pm@vger.kernel.org,
        Russell King <rmk@armlinux.org.uk>
Subject: Re: Regression in next with use printk_safe buffers in printk
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On (02/15/17 20:03), Tony Lindgren wrote:
> * Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> [170215 17:32]:
> > On (02/15/17 10:01), Tony Lindgren wrote:
> > [..]
> > > Below is another issue I noticed caused by commit f975237b7682 that
> > > I noticed during booting.
> > 
> > do you mean that with f975237b7682 you _always_ see that illegal RCU
> > usage warning?
> 
> Yeah on every boot on devices using cpuidle_coupled.

does this mean that with the printk-safe patches reverted
(so, basically, the same conditions module 4 printk patches)
you don't see illegal RCU usage reports? at the moment I can't
see any connection between f975237b7682 and RCU usage from idle CPU.

[..]

> > ---
> > 
> > diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
> > index 7180088cbb23..34da86e73d00 100644
> > --- a/kernel/printk/printk.c
> > +++ b/kernel/printk/printk.c
> > @@ -1563,7 +1563,7 @@ static void call_console_drivers(const char *ext_text, size_t ext_len,
> >  {
> >  	struct console *con;
> >  
> > -	trace_console(text, len);
> > +	trace_console_rcuidle(text, len);
> >  
> >  	if (!console_drivers)
> >  		return;
> > 
> > ---
> > 
> > 
> > I need to look more at this.
> 
> That fixes it for me thanks, so feel free to add:
> 
> Tested-by: Tony Lindgren <tony@atomide.com>

thanks.

	-ss