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

On Sat, Aug 25, 2012 at 03:16:49PM +0200, Frederic Weisbecker wrote:

On Fri, Aug 24, 2012 at 08:50:47PM -0700, Paul E. McKenney wrote:

quoted

On Sat, Aug 25, 2012 at 02:19:14AM +0100, Ben Hutchings wrote:

quoted

On Fri, 2012-08-24 at 14:26 -0700, Paul E. McKenney wrote:

quoted

On Thu, Aug 23, 2012 at 04:58:24PM +0200, Frederic Weisbecker wrote:

quoted

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() ?

In theory, definitely.  In practice, they haven't been running into it,
or they would be reporting hangs.

							Thanx, Paul