On Thu, Jan 16, 2014 at 09:12:14PM -0800, Andrew Morton wrote:

On Thu, 16 Jan 2014 23:57:51 -0500 Steven Rostedt [off-list ref] wrote:

quoted

When PROVE_LOCKING and PREEMPT is configured, the preempt state
tracking is active. Testing this out, I added a module that did the
following:

So I assume your kernel at least has no instances of this bug, so we
don't need the patch ;) It *is* a fairly daft thing to do.

Yeah, its exceedingly daft, but I do run into it every so often. Say
once a year or so.

Also, its usually not really a problem on 'normal' kernels, but it
absolutely blows on -rt.