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Date: Thu, 15 Feb 2024 09:39:00 -0800
From: Ira Weiny <ira.weiny@intel.com>
To: Jonathan Cameron <Jonathan.Cameron@huawei.com>, Steven Rostedt
	<rostedt@goodmis.org>
CC: Ira Weiny <ira.weiny@intel.com>, "Rafael J. Wysocki" <rafael@kernel.org>,
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	<linux-cxl@vger.kernel.org>, <linux-kernel@vger.kernel.org>, Dan Carpenter
	<dan.carpenter@linaro.org>, Masami Hiramatsu <mhiramat@kernel.org>, "Mathieu
 Desnoyers" <mathieu.desnoyers@efficios.com>,
	<linux-trace-kernel@vger.kernel.org>
Subject: Re: [PATCH v2] acpi/ghes: Prevent sleeping with spinlock held
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Jonathan Cameron wrote:
> On Wed, 14 Feb 2024 17:33:18 -0500
> Steven Rostedt <rostedt@goodmis.org> wrote:
> 
> > On Wed, 14 Feb 2024 14:19:19 -0800
> > Ira Weiny <ira.weiny@intel.com> wrote:
> > 
> > > > > Jonathan Cameron <Jonathan.Cameron@huawei.com> wrote:
> > > > >     
> > > > > > So I'm thinking this is a won't fix - wait for the printk rework to land and
> > > > > > assume this will be resolved as well?      
> > > > > 
> > > > > That pretty much sums up what I was about to say ;-)
> > > > > 
> > > > > tp_printk is more of a hack and not to be used sparingly. With the right
> > > > > trace events it can hang the machine.
> > > > > 
> > > > > So, you can use your internal patch locally, but I would recommend waiting
> > > > > for the new printk changes to land.    
> > > 
> > > Steven, Do you think that will land in 6.9?
> > >   
> > > > >
> > > > > I'm really hoping that will be soon!
> > > > >   
> > 
> > I may be like Jon Corbet predicting RT will land in mainline if I do.
> > 
> > -- Steve
> > 
> 
> 
> Agreed. Don't wait on printk fixes landing. (Well unless you are sure
> it's the year of the Linux desktop.) Reverting is fine for 6.8
> if you and Dan feel it's unwise to take this forwards (all the distros
> will backport it anyway and 6.8 isn't an LTS so no great rush)
> so fine to just queue it up again for 6.9 with this fix.
> 
> As Steve said, tp_printk is a hack (a very useful one) and
> hopefully no one runs it in production.

OMG...  I did not realize what tp_printk() was exactly.  I should have
looked closer.

Do we have evidence of its use in production?

I would love to not have to revert/respin,
Ira