Re: [ANNOUNCE] 3.0.1-rt11

On Mon, Aug 29, 2011 at 12:57:21PM -0700, Frank Rowand wrote:

On 08/26/11 16:55, Paul E. McKenney wrote:

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On Wed, Aug 24, 2011 at 04:58:49PM -0700, Frank Rowand wrote:

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On 08/13/11 03:53, Peter Zijlstra wrote:

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Whee, I can skip release announcements too!

So no the subject ain't no mistake its not, 3.0.1-rt11 is there for the
grabs.

Changes include (including the missing -rt10):

  - hrtimer fix that should make RT_GROUP work again
  - RCU fixes that should make the RCU stalls go away
  - fixes SMP=n builds after breaking them in -rt9

I have a consistent (every boot) hang on boot.  With a few
hacks to get console output, I get the

  rcu_preempt_state detected stalls on CPUs/tasks

messages in the attached console log.

< snip >

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Hmmm...  The last few that I have seen that looked like this were
due to my messing up rcutorture so that the RCU-boost testing kthreads
ran CPU-bound at real-time priority.

Is it possible that something similar is happening on your system?

                                                        Thanx, Paul

I don't think so.  That would require CONFIG_RCU_TORTURE_TEST, correct?
And that is not set:

< way big snip >

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# CONFIG_RCU_TORTURE_TEST is not set
CONFIG_RCU_CPU_STALL_TIMEOUT=60
CONFIG_RCU_CPU_STALL_VERBOSE=y

I'm finally getting back to this today, so I'm starting to learn about
the RCU stall detector, so maybe I can make some more sense of this.

This condition does not require CONFIG_RCU_TORTURE_TEST, rather, my
bug in CONFIG_RCU_TORTURE_TEST was one way to make this happen.  Any
condition that prevents RCU_SOFTIRQ from ever executing can cause these
symptoms.

							Thanx, Paul