From mboxrd@z Thu Jan  1 00:00:00 1970
From: NeilBrown <neilb@suse.de>
Subject: Re: RCU locking issues in jbd2_dev_to_name
Date: Thu, 28 Jul 2011 08:45:31 +1000
Message-ID: <20110728084531.06aa878a@notabene.brown>
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	<7A69E96B-0763-4440-BE10-A39B808C44FA@mit.edu>
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Cc: linux-ext4@vger.kernel.org,
	"Paul E.McKenney" <paulmck@linux.vnet.ibm.com>
To: Theodore Tso <tytso@MIT.EDU>
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On Wed, 27 Jul 2011 07:28:27 -0400 Theodore Tso <tytso@MIT.EDU> wrote:

> 
> On Jul 27, 2011, at 3:41 AM, NeilBrown wrote:
> 
> > 
> > 
> > Hi Ted and all,
> > 
> > I've been exploring RCU usage in the kernel looking for strange things, and
> > jbd2_dev_to_name looks particularly strange.  The following patch explains
> > and addresses the issues that I found.  Comments welcome.
> 
> Yeah its broken.  But I have patches pending for the merge window that solve
> it by nuking the function altogether; the problem is calling a function from
> TP_PRINTK causes perf to die on the spot, terminating its tracing.  :-(
> 

Sounds painful...

If it is about to go, that is good enough for me.

Thanks,
NeilBrown