Re: [PATCH 00/11] rcu: Add missing RCU idle APIs on idle loop v2

[Frederic Weisbecker <fweisbec@gmail.com>]

On Fri, Aug 24, 2012 at 08:50:47PM -0700, Paul E. McKenney wrote:
> On Sat, Aug 25, 2012 at 02:19:14AM +0100, Ben Hutchings wrote:
> > On Fri, 2012-08-24 at 14:26 -0700, Paul E. McKenney wrote:
> > > On Thu, Aug 23, 2012 at 04:58:24PM +0200, Frederic Weisbecker wrote:
> > > > Hi,
> > > > 
> > > > Changes since v1:
> > > > 
> > > > - Fixed preempt handling in alpha idle loop
> > > > - added ack from Geert
> > > > - fixed stable email address, sorry :-/
> > > > 
> > > > This time I built tested everywhere but: h8300 (compiler internal error),
> > > > and mn10300, parisc, score (cross compilers not available in
> > > > ftp://ftp.kernel.org/pub/tools/crosstool/files/bin/x86_64/4.6.3/)
> > > > 
> > > > For testing, you can pull from:
> > > > 
> > > > git://github.com/fweisbec/linux-dynticks.git
> > > > 	rcu/idle-fix-v2 
> > > > 
> > > > Thanks.
> > > 
> > > I have queued these on -rcu branch rcu/idle:
> > > 
> > > 	git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git
> > > 
> > > This problem has been in place since 3.3, so it is hard to argue that
> > > it is a regression for this merge window.  I have therefore queued it
> > > for 3.7.
> > 
> > I don't follow that; I would expect any serious bug fix (serious enough
> > for a stable update) to be acceptable for 3.6 at this point.
> 
> OK, if any of the arch maintainers wishes to submit the patch to 3.6,
> they are free to do so -- just let me know and I will drop the patch from
> my tree.
> 
> That said, all this does is cause spurious warnings to be printed, so
> not sure it really qualifies as serious.  But I am happy to leave that
> decision with the individual arch maintainers -- it is their arch,
> after all, so their decision.

Couldn't that cause hung tasks due to long lasting synchronize_rcu() ?