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From: Thomas Gleixner <tglx@linutronix.de>
To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Linus Walleij <linus.walleij@linaro.org>,
	Santosh Shilimkar <santosh.shilimkar@ti.com>,
	Rob Herring <rob.herring@calxeda.com>,
	linux-rt-users <linux-rt-users@vger.kernel.org>,
	Gregoire Gentil <gregoire@gentil.com>
Subject: Re: cpufreq + PREEMPT_RT_FULL give bad context sleeping BUG
Date: Tue, 26 Mar 2013 22:44:53 +0100 (CET)	[thread overview]
Message-ID: <alpine.LFD.2.02.1303262243540.22263@ionos> (raw)
In-Reply-To: <alpine.LFD.2.02.1303262236300.22263@ionos>

On Tue, 26 Mar 2013, Thomas Gleixner wrote:

> On Tue, 26 Mar 2013, Sebastian Andrzej Siewior wrote:
> 
> > * Thomas Gleixner | 2013-03-26 22:07:45 [+0100]:
> > 
> > >> that means it should trigger on mainline as well.
> > >
> > >No. It won't. Mainline uses a spinlock which gets converted to a
> > >sleeping spinlock on rt.
> > >
> > >  (rt_spin_lock+0x30/0x64) from (clk_get_rate+0x30/0x54)
> > 
> > This is true but this spinlock in only available in the OOT code
> > Gregoire Gentil pointed out ([0]). In mainline we have a mutex in
> > drivers/clk/clk.c and this is what my omap4 blaze is using.
> > 
> > [0] http://dev.omapzoom.org/?p=integration/kernel-ubuntu.git;a=blob;f=arch/arm/plat-omap/clock.c;h=8c0e8fe2c5c51673e41e4304194d922dbfaedf38;hb=3e1c9f139425663ceee48f92e8d3f23158580334
> 
> Yeah, it's that way in mainline as well.

I meant, that the mutex is taken. So yes, this will cause a warning in
!RT too.


  reply	other threads:[~2013-03-26 21:44 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-03-22 22:10 [ANNOUNCE] 3.8.4-rt1 Thomas Gleixner
2013-03-23  1:30 ` Luis Claudio R. Goncalves
2013-03-23 17:17   ` cpufreq + PREEMPT_RT_FULL give bad context sleeping BUG Gregoire Gentil
2013-03-26 20:51     ` Sebastian Andrzej Siewior
2013-03-26 21:07       ` Thomas Gleixner
2013-03-26 21:33         ` Sebastian Andrzej Siewior
2013-03-26 21:38           ` Thomas Gleixner
2013-03-26 21:44             ` Thomas Gleixner [this message]
2013-03-27 15:23               ` Gregoire Gentil
2013-04-25 15:23                 ` Sebastian Andrzej Siewior
2013-03-23 18:38   ` [ANNOUNCE] 3.8.4-rt1 Sebastian Andrzej Siewior
2013-03-24  1:15     ` Luis Claudio R. Goncalves
2013-03-23  3:31 ` Luis Claudio R. Goncalves

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